We thank Ivan Laermans, Rosita Kinart, Ann Lissens (Centre for Surgical Technologies, KU Leuven, Leuven, Belgium). Jo Verbinnen and Kristof Reyniers (Vesalius Institute of Anatomy, Faculty of Medicine, KU Leuven, Leuven, Belgium) provided technical support during the experiment. We thank Leen Mortier for the help with data and manuscript management. We thank FEG Textiltechniken for manufacturing prototype meshes, sterilizing them, and donating them unconditionally for research.

Ethical approval for this experiment was obtained from the Ethics Committee on Animal Experimentation of the KU Leuven (P065/2013). Animals were treated in accordance with current national guidelines on animal welfare.
1. Material and the Experimental Animal
<ol>
	<li>Surgery preparation
	<ol>
		<li>In the surgical theater cover a table with a sterile drape and prepare one sterile curved trocar (Figure 1, panel A), sterile surgical instruments, sutures, and sterile gauze. Perform the entire surgical procedure in sterile conditions if the experiment includes follow-up. Place all instruments on the table to be ready for use during surgery.</li>
		<li>Remove a sterile rectangular implant and/or an implant with anchoring arms from the sterile package and put them on the table covered with sterile drape (Figure 1B, C, and D).</li>
	</ol>
	</li>
</ol>
<img alt="Figure 1" src="/files/ftp_upload/55706/55706fig1.jpg" /> 
Figure 1: Trocar and Implants. (A) Schematic drawing of the trocar. (B) H-shaped polyvinylidene fluoride (PVDF) implant, with a detail of the central part (panel C). Its shape was inspired by the four-arm meshes currently available for transvaginal prolapse repair. The rectangular body (30 x 40 mm2) is laterally extended by four outstretched arms (150 x 10 mm2). The dimensions of the arms are designed to be long enough to pierce the relevant suspension structures, based on earlier anatomical studies17. (D) The rectangular implant (30 x 40 mm2). Both implants were made of polyvinylidene fluoride; textile characteristics and properties are in Table 1.
<ol start="2">
	<li>Experimental animal (Ewe, 45-60 kg)
	<ol>
		<li>Administer premedication of 1 mL of 15 mg/mL atropine sulfate and 1 mL/50 kg of xylazine HCl intramuscularly (i.m.) 30 min before the surgical procedure.</li>
		<li>After 30 min, ensure that the premedication has made the sheep lethargic and sleepy.</li>
		<li>Insert an intravenous catheter into the jugular vein and administer 0.075 mL/kg of ketamine 100 mg/mL HCl. Confirm deep anesthesia by observing the lack of reaction to painful stimuli.</li>
		<li>Move the animal onto the surgical table and secure its airways by intubation. Maintain the anesthesia with 2.5% isoflurane in 5 L/min oxygen.</li>
		<li>Keep the intravenous line inserted in the jugular vein and supply 500 mL of saline solution at a flow rate of 150 mL/h.</li>
		<li>Administer prophylactic antibiotics i.m. (amoxicillin clavulanate, 7 mg/kg) and post-operative analgesics (buprenorfin and chlorocresol, 1 mL) or the equivalent according to local protocols.</li>
		<li>Place the animal in lithotomy position on the end of the surgical table and secure its limbs, with the hips in hyper-flexion, using ropes (Figure 2, panel A).</li>
		<li>Manually empty the bladder and rectum by pushing on them trans-vaginally.</li>
		<li>Shave the perineum, the medial part of the thigh, and the tail folds and disinfect with polyvidone iodium 7.5% (Figure 2, panel B and C).</li>
	</ol>
	</li>
</ol>
<img alt="Figure 2" src="/files/ftp_upload/55706/55706fig2.jpg" /> 
Figure 2: Animal Surgery. (A) A sheep placed in the supine position, with the hips hyper-flexed by securing the lower limbs. (B) The external entrance points for trocar insertion are on the ventral side (empty arrow) and dorsally on the lateral tail folds (full arrow). (C) Position of the ventral insertion points; the dashed line in the middle represents the midsagittal plane of the animal. (D) Dissected rectovaginal septum. (E) Insertion of the ventral trocar through the muscles on the medial side of the thigh, the obturator foramen, and the paravaginal space. The trajectory of the piercing trocar is controlled with the finger. (F and G) Once the trocar is in place, the wire sling (open arrow) is advanced and loaded with the arm of the vaginal mesh. (H) Final position of the ventral (full arrows) and dorsal (empty arrow) arms. (I) The central part is placed tension-free between the vaginal wall and the rectal adventitia.
<ol start="10" style="margin-left: 40px;">
	<li>Prepare personnel for a surgery in sterile conditions. Put on a surgical cap and mouth mask, wash hands for surgery, and put on a surgical gown and sterile gloves.</li>
	<li>Cover the animal with a sterile drape and make an opening above the genital hiatus.</li>
</ol>
2. Surgical Procedure
<ol>
	<li>Preparation of the rectovaginal septum
	<ol>
		<li>Grasp the dorsal vaginal wall 3 cm cranial to the hymeneal ring using Allis forceps.</li>
		<li>Take a syringe loaded with 10 mL of saline and fitted with a 22 G needle. Insert it through the vaginal epithelium (approximately 3 - 4 mm deep) and into the midline of the rectovaginal septum, 1.5 cm cranial to the hymeneal ring.</li>
		<li>Perform &#34;aqua-dissection&#34; by injecting saline in the rectovaginal septum11.</li>
		<li>Make a 3 cm-long midline incision on the vaginal epithelium, starting caudal to the Allis forceps (step 2.1.1) and ending at the hymeneal ring using a scalpel. Enter the recto-vaginal space through this incision.</li>
		<li>Place the self-retaining retractor (see the Table of Materials) over the perineum and place four sharp stay hooks in the vaginal incision to keep it open.</li>
		<li>With your finger, bluntly dissect the recto-vaginal fascia from the vaginal wall laterally towards the pelvic side walls and cranially up to the caudal aspect of the cul-de-sac. Create suitable space for the 30 x 40 mm2 central part of the mesh (Figure 2, panel D).</li>
		<li>Perform haemostasis with haemostatic forceps or a crisscross haemostatic ligature whenever necessary. 
		NOTE: Small bleeders can be clamped with the hemostatic forceps. This crushes the vessel and initiates the natural coagulation cascade. For stronger bleeding, grasp the bleeding vessel with forceps and place a crisscross ligature, securing it with a square knot. At this point, one can either insert the rectangular implant (step 2.2) or continue with the dissection to insert the implant with anchoring arms (step 2.3).</li>
	</ol>
	</li>
	<li>Flat mesh insertion
	<ol>
		<li>Insert the vaginal retractor into the vaginal incision to allow a better view of the cranial part of the dissected area.</li>
		<li>Suture the left and right cranial corner of the implant with a simple interrupted 3/0 polypropylene suture on the left and right sides of the most cranial aspect of the dissected recto-vaginal space. Cut the residual suture material. Keep the suture away from the vaginal lumen (i.e., do not penetrate the vaginal wall). 
		NOTE: The implant is always sutured to the connective tissue comprising the recto-vaginal septum. The vaginal wall is not penetrated if the suture material cannot be seen in the vagina.</li>
		<li>Add one additional simple interrupted suture midway along the cranial aspect of the implant.</li>
		<li>Suture the lateral edges of the implant midway onto the surrounding connective tissue with a simple interrupted 3/0 polypropylene. Keep the implant as flat as possible and tension-free.</li>
		<li>Suture the left and right caudal corners with simple interrupted 3/0 polypropylene sutures on the left and right sides of the most caudal aspect of the rectovaginal space.</li>
		<li>Add one additional simple interrupted suture midway along the caudal aspect of the implant.</li>
		<li>Close the vaginal incisions with a running 3/0 polyglactin suture.</li>
	</ol>
	</li>
	<li>Insertion and anchoring of implant with arms (trocar-guided technique).
	<ol>
		<li>Continue the dissection of the recto-vaginal space created in step 2.1 cranio-ventrally to reach the medial aspect of the obturator foramen, which can easily be palpated.</li>
		<li>Dissect the space caudo-laterally to reach the caudal aspect of the sacrotuberous ligament and the caudally located coccygeus muscle.</li>
		<li>With a no. 24 blade, make four 1 cm-wide incisions on the vulvar side, cutting through the skin and superficial muscular fascia (Figure 2, panel B and C).</li>
		<li>Make two &#8220;ventral&#8221; incisions on the medial aspect of the thigh, proximately 4 cm cranial from the caudal border of the sciatic arch (i.e., the inferior border of the symphysis) and 3 cm lateral from the midline (Figure 2, panel C).</li>
		<li>Make two &#34;dorsal&#34; incisions at the level of the insertion of the tail folds, 2 cm medial to the tuber ischiadicum, which can be easily palpated (Figure 2, panel B).</li>
		<li>Place a curved trocar through one of the ventral incisions (Figure 2, panel E).</li>
		<li>Pass the trocar through the adductor magnus muscle, the external obturator, and the medial aspect of the obturator foramen.</li>
		<li>Control the progression of the trocar with a finger inserted through the vaginal incision. Guide its tip to the tendinous arc of the levator ani muscle (Figure 2, panel E).</li>
		<li>Expose the guiding wire in the vaginal wall incision and load it with the corresponding ipsilateral cranial mesh arm (Figure 2, panel F).</li>
		<li>Pull the trocar loaded with the mesh arm through the above structures. Keep the arm tension-free.</li>
		<li>Repeat the process with the second cranial arm through the ventral incision on the other side of the animal.</li>
		<li>Through one of dorsal incisions, pass the trocar through the coccygeus muscle, just distal to the sacrotuberous ligament (Figure 2, panel G).</li>
		<li>Expose the guide wire through the vaginal incision, grasp the dorsal arm of the mesh, and pull it out. Keep the arm tension-free and repeat on the other side.</li>
		<li>Adjust the position of the mesh by flattening it and applying tension to the arms, but keep the mesh tension-free (Figure 2, panel I; Figure 3).</li>
		<li>Fix the body of the mesh with a simple interrupted 3/0 polypropylene suture in the middle of its caudal border, securing it to the surrounding connective tissue.</li>
		<li>Cut the arms at the level of the skin and close all skin incisions with simple interrupted 3/0 polyglecaprone sutures (Figure 2, panel H).</li>
		<li>Close the vaginal incision with a running 3/0 polyglecaprone suture.</li>
	</ol>
	</li>
</ol>
<img alt="Figure 3" src="/files/ftp_upload/55706/55706fig3.jpg" /> 
Figure 3: Schematic Illustration of the Ovine Pelvis, with the Cranial Arms Passing through the Obturator Foramen and the Caudal Arms Passing through the Tail Folds. The broad sacrotuberous ligament is in blue. The smaller panel illustrates the position of the arms on an animal in recumbent position, just before shortening the excessive amount of material. The main panel shows the same but with the skin and muscles removed.

<ol>
	<li>Glazener, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Childbirth+and+prolapse:+Long-term+associations+with+the+symptoms+and+objective+measurement+of+pelvic+organ+prolapse.">Childbirth and prolapse: Long-term associations with the symptoms and objective measurement of pelvic organ prolapse.</a> BJOG An Int. J. Obstet. Gynaecol. 120 (2), 161-168 (2013).</li><li>Jia, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+and+safety+of+using+mesh+or+grafts+in+surgery+for+anterior+and/or+posterior+vaginal+wall+prolapse:+systematic+review+and+meta-analysis.">Efficacy and safety of using mesh or grafts in surgery for anterior and/or posterior vaginal wall prolapse: systematic review and meta-analysis.</a> BJOG. 115 (11), 1350-1361 (2008).</li><li>Maher, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transvaginal+mesh+or+grafts+compared+with+native+tissue+repair+for+vaginal+prolapse.">Transvaginal mesh or grafts compared with native tissue repair for vaginal prolapse.</a> Review. 2 (2), 10-13 (2016).</li><li>Nieminen, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Outcomes+after+anterior+vaginal+wall+repair+with+mesh:+a+randomized,+controlled+trial+with+a+3+year+follow-up.">Outcomes after anterior vaginal wall repair with mesh: a randomized, controlled trial with a 3 year follow-up.</a> Am. J. Obstet. Gynecol. 203 (3), e1-e8 (2010).</li><li>Abramowitch, S. D., Feola, A., Jallah, Z., Moalli, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+mechanics,+animal+models,+and+pelvic+organ+prolapse:+a+review.">Tissue mechanics, animal models, and pelvic organ prolapse: a review.</a> Eur. J. Obstet. Gynecol. Reprod. Biol. 144, S146-S158 (2009).</li><li>Couri, B., Lenis, A., Borazjani, A., Paraiso, M. F. R., Damaser, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+female+pelvic+organ+prolapse:+lessons+learned.">Animal models of female pelvic organ prolapse: lessons learned.</a> Expert Rev. Obs. Gynecol. 7 (3), 249-260 (2012).</li><li>Deprest, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biology+behind+fascial+defects+and+the+use+of+implants+in+pelvic+organ+prolapse+repair.">The biology behind fascial defects and the use of implants in pelvic organ prolapse repair.</a> Int. Urogynecol. J. Pelvic Floor Dysfunct. 17, S16-S25 (2006).</li><li>Ozog, Y., Mazza, E., De Ridder, D., Deprest, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+effects+of+polyglecaprone+fibers+in+a+polypropylene+mesh+after+abdominal+and+rectovaginal+implantation+in+a+rabbit.">Biomechanical effects of polyglecaprone fibers in a polypropylene mesh after abdominal and rectovaginal implantation in a rabbit.</a> Int. Urogynecol. J. 23 (10), 1397-1402 (2012).</li><li>Manodoro, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Graft-related+complications+and+biaxial+tensiometry+following+experimental+vaginal+implantation+of+flat+mesh+of+variable+dimensions.">Graft-related complications and biaxial tensiometry following experimental vaginal implantation of flat mesh of variable dimensions.</a> BJOG. 120 (2), 244-250 (2013).</li><li>Endo, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cross-linked+xenogenic+collagen+implantation+in+the+sheep+model+for+vaginal+surgery.">Cross-linked xenogenic collagen implantation in the sheep model for vaginal surgery.</a> Gynecol. Surg. , 113-122 (2015).</li><li>Feola, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Host+reaction+to+vaginally+inserted+collagen+containing+polypropylene+implants+in+sheep.">Host reaction to vaginally inserted collagen containing polypropylene implants in sheep.</a> Am. J. Obstet. Gynecol. 212 (4), e1-e474 (2015).</li><li>Barnhart, K. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Baseline+dimensions+of+the+human+vagina.">Baseline dimensions of the human vagina.</a> Hum. Reprod. 21 (6), 1618-1622 (2006).</li><li>Tayrac, R., Alves, A., Th&#233;rin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collagen-coated+vs+noncoated+low-weight+polypropylene+meshes+in+a+sheep+model+for+vaginal+surgery.+A+pilot+study.">Collagen-coated vs noncoated low-weight polypropylene meshes in a sheep model for vaginal surgery. A pilot study.</a> Int. Urogynecol. J. Pelvic Floor Dysfunct. 18 (5), 513-520 (2007).</li><li>Sobiraj, A., Busse, G., I, H. B. O. S. E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ivastigation+into+the+blood+plasma+profiles+progesterone+in+sheep+sufferingform+vaignal+inversion+and+prolapse.">Ivastigation into the blood plasma profiles progesterone in sheep sufferingform vaignal inversion and prolapse.</a> Br. Vet. J. 142 (142), 218-223 (1986).</li><li>Reisenauer, C., Kirschniak, A., Drews, U., Wallwiener, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomical+conditions+for+pelvic+floor+reconstruction+with+polypropylene+implant+and+its+application+for+the+treatment+of+vaginal+prolapse.">Anatomical conditions for pelvic floor reconstruction with polypropylene implant and its application for the treatment of vaginal prolapse.</a> Eur. J. Obstet. Gynecol. Reprod. Biol. 131, 214-225 (2007).</li><li>Carey, M., Slack, M., Higgs, P., Wynn-Williams, M., Cornish, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vaginal+surgery+for+pelvic+organ+prolapse+using+mesh+and+a+vaginal+support+device.">Vaginal surgery for pelvic organ prolapse using mesh and a vaginal support device.</a> BJOG An Int. J. Obstet. Gynaecol. 115 (3), 391-397 (2008).</li><li>Urbankova, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+anatomy+of+the+ovine+and+female+pelvis.">Comparative anatomy of the ovine and female pelvis.</a> Gynecol. Obstet. Invest. , (2016).</li><li>Maurer, M. M., R&#246;hrnbauer, B., Feola, a., Deprest, J., Mazza, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+biocompatibility+of+prosthetic+meshes:+A+comprehensive+protocol+for+mechanical+characterization.">Mechanical biocompatibility of prosthetic meshes: A comprehensive protocol for mechanical characterization.</a> J. Mech. Behav. Biomed. Mater. 40, 42-58 (2014).</li><li>Leval, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+Surgical+Technique+for+the+Treatment+of+Female+Stress+Urinary+Incontinence.">Novel Surgical Technique for the Treatment of Female Stress Urinary Incontinence.</a> Transobturator Vaginal Tape Inside-Out. Eur. Urol. 44 (6), 724-730 (2003).</li><li>Reisenauer, C., Kirschniak, A., Drews, U., Wallwiener, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transobturator+vaginal+tape+inside-out.">Transobturator vaginal tape inside-out.</a> Eur. J. Obstet. Gynecol. Reprod. Biol. 127 (1), 123-129 (2006).</li><li>Bafghi, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bowel+perforation+as+late+complication+of+tension-free+vaginal+tape.">Bowel perforation as late complication of tension-free vaginal tape.</a> J Gynecol Obs. Biol Reprod. 34 (6), 606-607 (2005).</li><li>Hinoul, P., Vanormelingen, L., Roovers, J. P., de Jonge, E., Smajda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomical+variability+in+the+trajectory+of+the+inside-out+transobturator+vaginal+tape+technique+(TVT-O).">Anatomical variability in the trajectory of the inside-out transobturator vaginal tape technique (TVT-O).</a> Int. Urogynecol. J. Pelvic Floor Dysfunct. 18 (10), 1201-1206 (2007).</li><li>Schaller, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Illustrated Veterinary Anatomical Nomenclature. , (2007).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serious+Complications+Associated+with+Transvaginal+Placement+of+Surgical+Mesh+for+Pelvic+Organ+Prolapse.">Serious Complications Associated with Transvaginal Placement of Surgical Mesh for Pelvic Organ Prolapse.</a> FDA Safety Communication. , (2016).</li><li>Reinier, M., Groep, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Final+Opinion+on+the+use+of+meshes+in+urogynecological+surgery.">Final Opinion on the use of meshes in urogynecological surgery.</a> SCENIHR- European Commission. , (2016).</li></ol>

This research program on the ovine model was supported by an unconditional grant from Medri and Blasingame, Burch, Garrard and Ashley (Atlanta GA, USA). Agreements are handled via the Leuven Research and Development transfer office. Sponsors did not interfere with the planning, execution, or reporting of this experiment, nor do they own the results. NS and LH are recipients of a grant from the EC in the FP7-framework (Bip-Upy project; NMP3-LA-2012-310389). AF was supported by a grant from the EC in the industry-academic partnership program (251356).

Here, we describe an experimental procedure in sheep, aimed to mimic vaginal dissection and transvaginal mesh insertion of an implant with or without anchoring arms. The subsequent steps and instruments were inspired by surgical procedures done for POP and stress urinary incontinence15,16,19,20. After initial anatomical dissections, there were still some problems during experimental mesh insert...

Pelvic organ prolapse is clinically diagnosed in half of women who had at least one vaginal delivery, but subjectively, it bothers half of women overall1. The mainstay of therapy is surgical reconstruction using either native tissue or implant materials, but each of these methods has its limitations, including recurrence or local complications2,3,4. The ideal implant has not yet been identified; hence, there is an ongoing demand for product innovation and for the development of a proper pipeline for preclinical experimentation prior to the introduction of new products and techniques to the market. One of the steps in this track is experimental evaluation on suitable animal models5,6. Ideally, they should mimic the anatomical, biomechanical, and biological environments. When it comes to the experimental evaluation of novel implants, they are typically tested first in smaller models, either for biocompatibility or for the reconstruction of abdominal wall defects. That type of experiments has been criticized, because the implants are not inserted into the area of interest (i.e., the vagina)7. Vaginal surgery models are more scarce, certainly when the goal of the experiment is to document the biomechanical characteristics of explants. For this reason, there was a move from rabbits to sheep8. Adult ewes are large-animal models with a reasonably sized and accessible vagina. They can be used for the mid-term evaluation of novel implants, and it is possible to reproduce vaginal exposures with certain materials9,10,11,12,13. Not only the dimensions and anatomy of the ovine vagina and pelvic floor are comparable to those in humans, but also the spontaneous occurrence of prolapse, which occurs in 15% of ewes. Prolapse risk factors are overlapping (i.e., multiparity, previous history of POP, increased intra-abdominal pressure induced by a higher bodyweight or when grazing on hills, and comparable effects of (phyto)estrogens)6,14. In Europe, sheep are the only reasonable alternative, as research on non-human primates has been nearly completely banned. Here, the model was taken one step further by mimicking the transvaginal insertion of implants using trocars and guides for the tension-free placement of meshes into the recto-vaginal septum. This was followed by fixing the implant using anchoring with arms through the ligaments of muscles, which can be considered equivalent to clinical practice15,16. So far, this technique has not been studied, though many believe that specific complications may occur due to the use of these longer strips and/or the piercing of anatomical structures.
In an earlier detailed anatomical study, the ovine pelvic floor was compared to the female pelvis17. When it comes to anchoring the implant, sheep do not have the sacrospinous ligament, yet they do have a very well-developed and broad sacrotuberous ligament. The pudendal nerve runs ventrally over it, making it unsafe to use this landmark as a suspension point. Conversely, the coccygeus muscle and its fascia, as well as the obturator membrane, are accessible through the rectovaginal space. Here, the access and position of the anatomical structures for the fixation of anchoring arms is proposed. The instruments that can be used to position the mesh are discussed. Finally, the relationship of the arms or trocars to adjacent anatomical structures, such as vessels and nerves, as well as potential intraoperative complications, are also described.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Animals:&#160;</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>parous female sheep (45 - 65 kg)</td>
			<td>Zo&#246;technical Institute of the KU Leuven</td>
			<td>NA</td>
			<td>experimetnal animal</td>
		</tr>
		<tr>
			<td>Sterile clothing:&#160;</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>sterile drape 45 x 75 cm</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>33002</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>sterile OR drape 150 x 180 cm</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>33009</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>sterile glowes 2x</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>16652</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>sterile surgical gown 2x</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>19342</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>surgical head cap 2x</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>17427</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>surgical face mask 2x</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>11983</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>Other surgical material</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>implant</td>
			<td>FEG Textiltechnik GmbH, Aachen, Germany</td>
			<td>NA</td>
			<td>purposely designed implant</td>
		</tr>
		<tr>
			<td>3/0 polypropylene suture</td>
			<td>Prolene, Ethicon, Diegem, Belgium</td>
			<td>8762H</td>
			<td>suture material</td>
		</tr>
		<tr>
			<td>3/0 polygecaprone suture</td>
			<td>Vicryl, Ethicon</td>
			<td>J311H</td>
			<td>suture material</td>
		</tr>
		<tr>
			<td>gauze swabs 10 x 10 cm 10x, 12-ply</td>
			<td>Lohmann &#38; Rauscher, Regensdorf, Germany</td>
			<td>11574</td>
			<td>other material</td>
		</tr>
		<tr>
			<td>syringe 20 mL</td>
			<td>Becton Dickinsosn S.A., Madrid, Spain</td>
			<td>300613</td>
			<td>aqua-dissection</td>
		</tr>
		<tr>
			<td>needle 16 gauge</td>
			<td>Terumo, Leuven, Belgium</td>
			<td>NN-2238R</td>
			<td>aqua-dissection</td>
		</tr>
		<tr>
			<td>Surgical equipment:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>blade no.22</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>10022-00</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Allis tissue forceps 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>11091-15</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Standart pattern forceps 1x2 theeth 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>11023-14</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Standart pattern forceps straight serrated 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>11000-14</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Scalpel handle 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>10004-13</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Halstead-Mosquito forceps 2x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>13008-12</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Standart pattern scissors 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>14001-14</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Metzenbaum scissors 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>14016-18</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Crile Wood needle holder 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>12003-15</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Kell forceps 1x</td>
			<td>Fine science isntruments, Heidelberg, Germany</td>
			<td>13018-14</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Long Starr Self-Retaining Retractor with eight 5mm sharp stay hooks</td>
			<td>Cooper Surgical, Tumbull, USA</td>
			<td>3704</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Heaney Simon Vaginal Retractor</td>
			<td>Medical supplies &#38; equipments co., Katy, Texas, USA</td>
			<td>403-129FSI</td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>Trocar (Insnare)</td>
			<td>Bard, West Sussex, United Kingdom</td>
			<td>NA</td>
			<td>any trocar on market for transvaginal mesh implantation</td>
		</tr>
		<tr>
			<td>Medication:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>amoxilicilline clavulanate 1000mg / 300 mL (Ampiciline)</td>
			<td>GSK, Wavre, Belgium</td>
			<td>NA</td>
			<td>antibiotics</td>
		</tr>
		<tr>
			<td>buprenorfin 0.3 mg/mL + chlorocresol 1.35 mg/mL (Vetregesic)</td>
			<td>Ecuphar, Oostkamp, Belgium</td>
			<td>NA</td>
			<td>analgesia</td>
		</tr>
		<tr>
			<td>ketamin HCL 100mg/mL (Ketamine 1000)</td>
			<td>Ceva Sante Animale, Brussels, Belgium</td>
			<td>NA</td>
			<td>anesthesia</td>
		</tr>
		<tr>
			<td>isoflurane (IsoFlo)</td>
			<td>Abbott Laboratories Ltd, Maidenhead, Berkshire, UK</td>
			<td>NA</td>
			<td>anesthesia</td>
		</tr>
		<tr>
			<td>polyvidone iodium 7.5% (Braunol)</td>
			<td>B. Braun Medical, Machelen, Belgium</td>
			<td>NA</td>
			<td>local desinfection</td>
		</tr>
		<tr>
			<td>saline solution 500ml</td>
			<td>B. Braun Medical, Machelen, Belgium</td>
			<td>NA</td>
			<td>aqua-dissection</td>
		</tr>
		<tr>
			<td>Xxylazine HCl , 1 mL/50 kg&#160;</td>
			<td>Vexylan, Ceva Sante Animale, Belgium</td>
			<td>NA</td>
			<td>premedication</td>
		</tr>
		<tr>
			<td>atropine Sulfate 15 mg/ml (),</td>
			<td>Viatris, Belgium</td>
			<td>NA</td>
			<td>premedication</td>
		</tr>
	</tbody>
</table>

transvaginal mesh insertion in the ovine model

This protocol describes mesh insertion into the rectovaginal septum in sheep using a single vaginal incision technique, with and without the trocar-guided insertion of anchoring arms. Parous sheep underwent the dissection of the rectovaginal septum, followed by the insertion of an implant with or without four anchoring arms, both designed to fit the ovine anatomy. The anchoring arms were put in place using a trocar and an "outside-in" technique. The cranial arms were passed through the obturator, gracilis, and adductor magnus muscles. The caudal arms were fixed near the sacrotuberous ligament, through the coccygeus muscles. This technique allows for the mimicking of surgical procedures performed in women suffering from pelvic organ prolapse. The anatomical spaces and elements are easily identified. The most critical part of the procedure is the insertion of the cranial trocar, which can easily penetrate the peritoneal cavity or the surrounding pelvic organs. This can be avoided by a more extensive retroperitoneal dissection and by guiding the trocar more laterally. This approach is designed only for experimental testing of novel implants in large animal models, as trocar-guided insertion is currently not used clinically.

Management in a Longer Observation Setup
Following the surgical procedure, vaginal packing (a saline-solution-soaked gauze package inserted in the vagina immediately after the surgery) may be inserted for 24 h to secure the implant position. The sheep should be placed in a recovery cage and its respiratory function followed until full recovery. Later, it is possible to place the sheep in the stable and to allow ...

Watch this Scientific Journal Video about Transvaginal Mesh Insertion in the Ovine Model at JoVE.com

Transvaginal Mesh Insertion in the Ovine Model

This protocol describes mesh implantation in the ovine rectovaginal septum using a single vaginal incision technique, with and without the trocar-guided insertion of anchoring arms.

This protocol describes mesh insertion into the rectovaginal septum in sheep using a single vaginal incision technique, with and without the trocar-guided ...

transvaginal-mesh-insertion-in-the-ovine-model

Research

JoVE Journal

Medicine

15.9K Views.  Clinical Specialties Research Groups, Faculty of Medicine, KU Leuven. This protocol describes mesh implantation in the ovine rectovaginal septum using a single vaginal incision technique, with and without the trocar-guided insertion of anchoring arms. 

Video: Transvaginal Mesh Insertion in the Ovine Model

The Monoiodoacetate Model of Osteoarthritis Pain in the Mouse

A major symptom of patients with osteoarthritis (OA) is pain that&#160;is triggered by peripheral as well as central changes within the pain pathways. The current treatments for OA pain such as NSAIDS or opiates are neither sufficiently effective nor devoid of detrimental side effects. Animal models of OA are being developed to improve our understanding of OA-related pain mechanisms and define novel pharmacological targets for therapy. Currently available models of OA in rodents include surgical and chemical interventions into one knee joint. The monoiodoacetate (MIA) model has become a standard for modelling joint disruption in OA in both rats and mice. The model, which is easier to perform in the rat, involves injection of MIA into a knee joint that induces rapid pain-like responses in the ipsilateral limb, the level of which can be controlled by injection of different doses. Intra-articular injection of MIA disrupts chondrocyte glycolysis by inhibiting glyceraldehyde-3-phosphatase dehydrogenase and results in chondrocyte death, neovascularization, subchondral bone necrosis and collapse, as well as inflammation. The morphological changes of the articular cartilage and bone disruption are reflective of some aspects of patient pathology. Along with joint damage, MIA injection induces referred mechanical sensitivity in the ipsilateral hind paw and weight bearing deficits that are measurable and quantifiable. These behavioral changes resemble some of the symptoms reported by the patient population, thereby validating the MIA injection in the knee as a useful and relevant pre-clinical model of OA pain.
The aim of this article is to describe the methodology of intra-articular injections of MIA and the behavioral recordings of the associated development of hypersensitivity with a mind to highlight the necessary steps to give consistent and reliable recordings.

Osteoarthritis (OA), or degenerative joint disease, is a debilitating condition associated with pain that remains only partially controlled by available analgesics. Animal models are being developed to improve our understanding of OA-related pain mechanisms. Here we describe the methodology for the monoiodoacetate model of OA pain in the mouse.

A major symptom of patients with osteoarthritis (OA) is pain that&#160;is triggered by peripheral as well as central changes within the pain pathways. The ...

Ovine Lumbar Intervertebral Disc Degeneration Model Utilizing a Lateral Retroperitoneal Drill Bit Injury

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration have been developed. The ideal animal model should closely mimic the human intervertebral disc with regard to morphology, biomechanical properties and the absence of notochordal cells. The sheep lumbar intervertebral disc model fulfils these criteria. We present an ovine model of intervertebral disc degeneration utilizing a drill bit injury through a lateral retroperitoneal approach. The lateral approach significantly reduces the incision and potential morbidity associated with the traditional anterior approach to the ovine spine. Utilization of a drill-bit method of injury affords the ability to produce a consistent and reproducible injury, of precise dimensions, that initiates a consistent degree of intervertebral disc degeneration. The focal nature of the annular and nucleus pulposus defect more closely mimics the clinical condition of focal intervertebral disc herniation. Sheep recover rapidly following this procedure and are typically mobile and eating within the hour. Intervertebral disc degeneration ensues and sheep undergo necropsy and subsequent analysis at periods from eight weeks. We believe that the drill bit injury model of intervertebral disc degeneration offers advantages over more conventional annular injury models.

Intervertebral disc degeneration is a significant contributor to back pain and a leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration exist. We demonstrate an ovine model of intervertebral disc degeneration, utilizing a drill bit, which achieves a consistent disc injury and reproducible level of disc degeneration.

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous ...

In Vitro Assays to Assess Blood-brain Barrier Mesh-like Vessel Formation and Disruption

Blood-brain barrier (BBB) coverage plays a central role in the homeostasis of the central nervous system (CNS). The BBB is dynamically maintained by astrocytes, pericytes and brain endothelial cells (BECs). Here, we detail methods to assess BBB coverage using single cultures of immortalized human BECs, single cultures of primary mouse BECs, and a humanized triple culture model (BECs, astrocytes and pericytes) of the BBB. To highlight the applicability of the assays to disease states, we describe the effect of oligomeric amyloid-&#946; (oA&#946;), which is an important contributor to Alzheimer&#39;s disease (AD) progression, on BBB coverage. Further, we utilize the epidermal growth factor (EGF) to illuminate the drug screening potential of the techniques. Our results show that single and triple cultured BECs form meshwork-like structures under basal conditions, and that oA&#946; disrupts this cell meshwork formation and degenerates the preformed mesh structures, but EGF blocks this disruption. Thus, the techniques described are important for dissecting fundamental and disease-relevant processes that modulate BBB coverage.

In Vitro Assays to Assess Blood-brain Barrier Mesh-like Vessel Formation and Disruption

Maintaining blood-brain barrier coverage is key for the homeostasis of the central nervous system. This protocol describes in vitro techniques to delineate the fundamental and pathological processes that modulate blood-brain barrier coverage.

Blood-brain barrier (BBB) coverage plays a central role in the homeostasis of the central nervous system (CNS). The BBB is dynamically maintained by ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Laparoscopic Repair of Para-Esophageal Hernia Using Absorbable Biosynthetic Mesh

Para-esophageal hernia repairs are challenging procedures and there is no consensus on the optimal approach to repair. Mesh reinforcement has been associated with lesser hernia recurrence when compared to the primary suture repair. The type of mesh that is most appropriate is still debatable. Synthetic and biosynthetic materials have been studied in the literature. It is well documented that a synthetic mesh is associated with esophageal erosion and migration into the stomach. Though there are limited long-term data on biosynthetic mesh, the short-term results are excellent and promising.
This paper illustrates how a biosynthetic prosthesis can be safely used with fibrin glue fixation and anterior Dor fundoplication to repair any para-esophageal defect. The absorbable biosynthetic mesh has been shown to produce good long-term patient satisfaction outcomes and low recurrence rates compared to conventional methods including repair with synthetic mesh. This technique also avoids the risk of esophageal erosion whilst strengthening the repair. Tacks that are still widely used to secure the mesh can be abandoned due to the associated risk of developing cardiac tamponade, or other disastrous consequences. This repair method, also, highlights how the prosthesis can be fashioned into a V-shape and easily placed in an onlay fashion behind the esophagus. The protocol demonstrates an alternative and safer method for mesh fixation using fibrin glue.

Presented here is a protocol of para-esophageal hernia repair. Use of absorbable biosynthetic mesh avoids the risk of erosion through the esophagus whilst reinforcing the repair. Glue fixation is preferred to avoid the risk of trauma such as bleeding or cardiac tamponade, which are associated with stitches or tacks.

Para-esophageal hernia repairs are challenging procedures and there is no consensus on the optimal approach to repair. Mesh reinforcement has been ...

The Lower Body Positive Pressure Treadmill for Knee Osteoarthritis Rehabilitation

Here, based on a clinician&rsquo;s point-of-view, we propose a two-model lower body positive pressure (LBPP) protocol (walking and squatting models) in addition to a clinical, functional assessment methodology, including details for further encouragement of the development of non-drug surgical intervention strategies in knee osteoarthritis patients. However, we only present the effect of LBPP training in improvement of pain and knee function in one patient through three-dimensional gait analysis. The exact, long-term effects of this approach should be explored in future studies.

Here, based on a clinician&#8217;s point-of-view, we propose a two-model lower body positive pressure (LBPP) protocol (walking and squatting models) in addition to a clinical, functional assessment methodology, including details for further encouragement of the development of non-drug surgical intervention strategies in knee osteoarthritis patients. However, we only present the effect of LBPP training in improvement of pain and knee function in one patient through three-dimensional gait analysis. The exact, long-term effects of this approach should be explored in future studies.

Here, based on a clinician&rsquo;s point-of-view, we propose a two-model lower body positive pressure (LBPP) protocol (walking and squatting models) in ...

Intravitreal Injections in the Ovine Eye

There are several methods for the delivery of therapeutic agents to the retina, including intravitreal (IVT), subretinal, suprachoroidal, periocular, or topical administration. IVT drug delivery involves an injection into the vitreous humor of the eye, a gelatinous substance that fills the posterior chamber of the eye and maintains the shape of the eye globe. Although the IVT route is less specifically targeted than subretinal delivery, it is much less invasive and is widely used in clinical settings for a range of ocular diseases. 
We previously demonstrated the efficacy of intravitreal delivery of an adeno-associated virus (AAV)-mediated gene therapy product (AAV9.CLN5) in sheep with a naturally occurring CLN5 form of neuronal ceroid lipofuscinosis (NCL). Affected sheep received IVT gene therapy in one eye, with the other untreated eye serving as an internal control. Retinal structure and function were maintained in the treated eye up to 15 months after treatment, while the untreated eye displayed progressively declining function and severe atrophy during postmortem examination. Based on the sheep studies, the CLN5 gene therapy product was cleared as a candidate investigational new drug (IND) by the United States Food and Drug Administration in September 2021. This paper details the surgical protocol for IVT delivery of a therapeutic viral vector to the ovine eye.

Intravitreal injections were performed in the sheep eye with the aim of delivering viral-mediated gene therapy to the retina.

There are several methods for the delivery of therapeutic agents to the retina, including intravitreal (IVT), subretinal, suprachoroidal, periocular, or ...

Laparoscopic Non-Mesh Cerclage Pectopexy for Pelvic Organ Prolapse

Pelvic organ prolapse (POP) is widespread among the female population and significantly impairs the patient's quality of life. It is important to restore apical support for treating POP. Sacrocolpopexy and pectopexy are indicated for apical prolapse. Using a synthetic mesh in these techniques increases success by enhancing apical support. However, the implantation of synthetic mesh is associated with mesh-related complications. In addition, the exorbitant cost of synthetic mesh and lack of universal access limit the popularity of these procedures. The current study develops a unique technique known as laparoscopic non-mesh cerclage pectopexy (LNMCP), in which permanent cervical cerclage sutures are embedded in the round ligament until the iliopectineal ligament. The iliopectineal ligament was sutured, resulting in a firm cervical suspension. The procedure was successfully performed in 16 cases in the hospital. The surgical duration was 67.8 min &plusmn; 15.5 min, and the blood loss was 73.1 mL &plusmn; 51.1 mL. No procedural complications were seen. LNMCP is associated with an objective success rate of 100% and a subjective success rate of 93.8%. LNMCP for patients with apical prolapse obviates the need for a mesh, thereby avoiding complications associated with mesh erosion and reducing medical costs. In addition, it is easy to perform even in resource-poor areas without access to synthetic mesh.

The present pilot study describes the development of laparoscopic non-mesh cerclage pectopexy to treat pelvic organ prolapse. The procedure can be used to prevent any complications associated with the use of mesh.

Pelvic organ prolapse (POP) is widespread among the female population and significantly impairs the patient's quality of life. It is important to restore ...

Neuronavigation and Laparoscopy Guided Ventriculoperitoneal Shunt Insertion for the Treatment of Hydrocephalus

Hydrocephalus is a common adult neurosurgical condition typically requiring treatment with a cerebrospinal fluid (CSF) shunt, of which the ventriculoperitoneal (VP) shunt is the most common type. Unfortunately, the failure rates of VP shunts are alarmingly high, with up to 50% of patients requiring revision surgery within 2 years. VP shunt failure may occur due to infection, or catheter mispositioning, migration, and occlusion. We undertook a joint neurosurgery and general surgery collaboration in a 7-year prospective non-randomized consecutive quality improvement cohort study to reduce the rates of ventriculoperitoneal (VP) shunt failures in 224 adult patients at a tertiary care institution. The initiative combined the use of electromagnetic stereotactic neuronavigation to guide the placement of the proximal catheter and laparoscopy to place the distal catheter under direct visualization. With laparoscopic assistance, the distal catheter was anchored through a small hole created in the falciform ligament and placed into the right retrohepatic space, free from the omentum, adhesions, or bowel that might obstruct the catheter tip. The surgeries were performed using a shunt infection prevention protocol to reduce the risk of shunt infections. Here, we present an intraoperative video of the surgical procedure. Compliance with shunt infection reduction strategies and the combined utilization of neuronavigation and laparoscopy techniques in adult VP shunt surgery resulted in a 44% reduction in the risk of overall shunt failure. The significant positive impact with regard to shunt-failure-free patient outcomes among patients who underwent VP shunt surgery using this strategy underscores the value associated with the use of these modern intraoperative techniques and cross-specialty collaboration during VP shunt surgery.

Patient outcomes of ventriculoperitoneal (VP) shunt surgery, the mainstay treatment for hydrocephalus in adults, are poor due to high shunt failure rates. We present intraoperative footage of VP shunt insertion using neuronavigation and laparoscopy guidance, with the goal to reduce the risks of proximal and distal shunt catheter failures, respectively.

Hydrocephalus is a common adult neurosurgical condition typically requiring treatment with a cerebrospinal fluid (CSF) shunt, of which the ...

Application of a New Mesh Fixation Method in Laparoscopic Incisional Hernia Repair

Laparoscopic incisional hernia repair using intraperitoneal onlay mesh (IPOM) is one of the most widely used minimally invasive methods for repairing incisional hernias. The laparoscopic IPOM involves implanting the mesh into the abdominal cavity through laparoscopy to repair an abdominal wall hernia. In the IPOM surgery, after the closure of the hernia ring, an anti-adhesion mesh is placed laparoscopically. The correct placement of this mesh is critical to the success of the method, and surgical skills are required to achieve perfect placement. If the mesh placement is not mastered properly, the operation and anesthesia time will be prolonged. In addition, improper placement of the mesh can lead to serious consequences, such as intestinal obstruction and mesh infection. A "contraposition and alignment" mesh fixation method is described in this study, which involves pre-marking the fixation position of the mesh to reduce the difficulty of mesh placement. A properly placed mesh is completely flat on the peritoneum, the edges are not curled or wrapped, and the mesh is adhered firmly such that there is no displacement after removing the pneumoperitoneum pressure. The "contraposition and alignment" mesh fixation technique offers the advantages of reliable placement of the mesh and fewer complications than other techniques, and it is easy to learn and master. It also allows for positioning the nail gun in advance based on the anatomy of the incisional hernia. This enables the use of the minimum number of nails possible while still ensuring good fixation, which can reduce the occurrence of complications and reduce the cost of surgery. Thus, the mesh fixation method described here is highly suitable for clinical applications based on the aforementioned advantages.

Presented here is a method for improving the mesh placement in laparoscopic incisional hernia repair, which can shorten the time required for mesh fixation and reduce the occurrence of postoperative chronic pain.

Laparoscopic incisional hernia repair using intraperitoneal onlay mesh (IPOM) is one of the most widely used minimally invasive methods for repairing ...