The authors would like to thank the second affiliated hospital of KMMU for providing cases and medical records related to this work. There is no funding support for this study.

The surgical method described in this paper has been approved by the Ethics Committee of the Second Affiliated Hospital of Kunming Medical University, and the use of patient surgical videos has been authorized. Informed consent was obtained from the patients, and patient data was used for presentation.
1. Instruments for operation
<ol>
	<li>Ensure that the display camera system and holmium laser are working properly.</li>
</ol>
2. Preparation for operation
<ol>
	<li>Use the following inclusion criteria to select participants for this study.
	<ol>
		<li>All patients who had been diagnosed with azoospermia or oligospermia and had consented to surgery.</li>
		<li>Semen volume less than 1.5 mL, pH&#60;7.2. Seminal plasma fructose &#8804;13 &#181;M/single ejaculation.</li>
		<li>Magnetic resonance imaging (MRI) revealed cysts in the ejaculatory duct area and enlarged bilateral seminal vesicle glands (Figure 1). 
		NOTE: It is difficult to identify prostate cysts and ejaculatory duct cysts through imaging accurately. We usually confirm the diagnosis through surgery when seminal vesicle dilatation has a width greater than 17 mm10.</li>
		<li>Sex hormone levels are within the normal range. The testicular volume was more than 15 mL (individual testicular volume). 
		NOTE: The purpose of testicular volume &#62;15 mL is to rule out azoospermia caused by some testicular factors. Testicular volume was measured using ultrasound report data and Lambert&#39;s formula: L x W x H x 0.71.</li>
		<li>There were no diseases that affected the safety of surgery, such as poorly controlled hypertension and hyperglycemia, respiratory diseases, etc.</li>
	</ol>
	</li>
	<li>Use the following exclusion criteria to exclude participants from this study.
	<ol>
		<li>Patients with urethral stricture, acute urinary tract infection, severe coagulopathy, or other contraindications to anesthesia.</li>
		<li>The testicular volume was less than 12 mL.</li>
	</ol>
	</li>
	<li>Administer intravenous antibiotics 30 min before surgery to prevent infection. Typically, use 1.5 g cefuroxime sodium with 100 mL of 0.9% sodium chloride solution.</li>
</ol>
3. Operational procedure
<ol>
	<li>Position the patient in lithotomy for anesthesia induction using sufentanil (0.3 &#181;g/kg), propofol (2 mg/kg), and rocuronium bromide (0.8 mg/kg). Perform tracheal intubation once drugs take effect, connecting to the anesthesia machine for mechanical ventilation.</li>
	<li>Maintain with propofol (2 mg/kg/h), remifentanil (0.15 &#181;g/kg/min), and 2% sevoflurane to achieve a BIS value of 40-60. Inject rocuronium bromide intermittently for inotropic relaxation. Disinfect the lower abdomen and perineal area 3x with iodophor.</li>
	<li>Connect the seminal vesiculoscope to the display system. Insert the endoscope through the external urethral opening and carefully advance it toward the posterior urethra. The urethral mucosa appears smooth and reddish, confirming the accurate positioning of the urethra within the visual field and extending towards the posterior urethra.</li>
	<li>If successful, check that the raised structure of the urethra, known as the colliculus seminalis, is visible.On either side of the colliculus seminalis, check for two small openings of the ejaculatory ducts (Figure 2A).</li>
	<li>Guide a wire (Bard) through the affected side&#39;s ejaculatory duct opening, entering the ejaculatory duct cyst. Observe a significant area filled with cloudy fluid during the procedure (Figure 2B).</li>
	<li>Flush the cyst with saline until achieving clear vision, examining for abnormal openings in the seminal canal. Enter the ipsilateral seminal vesicle through the abnormal ejaculatory duct cyst opening, revealing multiple honeycombed ductal lumens (Figure 2C).</li>
	<li>Using a 40 W holmium laser, expand the diameter of the ejaculatory tube to approximately 5 mm, facilitating improved circulation of the flush fluid and providing a clearer view (Figure 2D).</li>
	<li>Cut the ejaculatory duct opening along the direction of urine flow, which may be conducive to preserving the anti-urine reflux mechanism.</li>
	<li>Identify and explore the symmetrical position of the abnormal ejaculatory duct opening on the affected side.</li>
	<li>Enter the seminal vesicle of the healthy side for further exploration.Gently insert it into the seminal vesicle at the lower left and right of the cysts. It is important to note that the exact location may vary (Figure 2E).</li>
	<li>Use the holmium laser to precisely incise and widen the contralateral artificial opening, allowing smooth passage for the endoscope. This marks the pivotal endpoint of the operation, where sperm in the vas deferens on both sides is effectively released through the opening of the ejaculatory duct on the affected side (Figure 2F).</li>
	<li>Indwell a Fr18 catheter and rinse continuously with physiological sodium chloride to prevent blood clots from blocking the catheter.</li>
</ol>
4. Postoperative care
<ol>
	<li>On the 1st day post-surgery, continuously irrigate the bladder for 6 h and supplement with glucose and electrolytes as needed.</li>
	<li>Remove the catheter on the 2nd day post-surgery. Ensure that the patient experiences no evident pain after surgery; instead, they are able to endure the primary discomfort from the catheter, which is manageable without medication. Do not administer antibiotics postoperatively to patients without pre-existing infections. Keep the hospital stay for 2 days.</li>
	<li>Instruct the patients to increase water intake, urinate frequently, and ejaculate as soon as possible after discharge, aiming for 1-2 times per week. Additionally, closely observe the semen volume.</li>
</ol>
5. Follow up
<ol>
	<li>Perform semen analysis in the 3rd month after surgery to ensure that the gag time requirement was met, and follow up after 3 months mainly through telephone interviews.</li>
	<li>Perform semen samples using the automatic sperm motility testing instrument and the automatic seminal plasma biochemical instrument. Compare the semen analysis results obtained before the surgery with those at the 3rd month post-surgery.</li>
</ol>
6. Statistical analysis
<ol>
	<li>Analyze the results using GraphPad software and expressed as mean &#177; SD. Normality tests were performed using Shapiro-Wilk tests.If the preoperative and postoperative differences are normally distributed, analyze using the paired t-test; otherwise, use non-parametric tests (Mann-Whitney). Analyze differences between preoperative and postoperative data by paired t-test. Statistical differences were regarded as significant when P &#60;0.05.</li>
</ol>

Seminal Vesiculoscope Laser-Assisted Surgery to Treat Ejaculatory Duct Blockage

<ol>
	<li>Avellino, G. J., Lipshultz, L. I., Sigman, M., Hwang, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transurethral+resection+of+the+ejaculatory+ducts:+etiology+of+obstruction+and+surgical+treatment+options.">Transurethral resection of the ejaculatory ducts: etiology of obstruction and surgical treatment options.</a> Fertil Steril. 111 (3), 427-443 (2019).</li><li>Modgil, V., Rai, S., Ralph, D. J., Muneer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+update+on+the+diagnosis+and+management+of+ejaculatory+duct+obstruction.">An update on the diagnosis and management of ejaculatory duct obstruction.</a> Nat Rev Urol. 13 (1), 13-20 (2016).</li><li>Paick, J., Kim, S. H., Kim, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ejaculatory+duct+obstruction+in+infertile+men.">Ejaculatory duct obstruction in infertile men.</a> BJU Int. 85 (6), 720-724 (2000).</li><li>Wang, H., 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=Transurethral+seminal+vesiculoscopy+using+a+6F+vesiculoscope+for+ejaculatory+duct+obstruction:+initial+experience.">Transurethral seminal vesiculoscopy using a 6F vesiculoscope for ejaculatory duct obstruction: initial experience.</a> J Androl. 33 (4), 637-643 (2012).</li><li>Galloway, M., Woods, R., Nicholson, S., Foggin, J., Elliott, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+audit+of+waiting+times+in+a+haematology+clinic+before+and+after+the+introduction+of+point-of-care+testing.">An audit of waiting times in a haematology clinic before and after the introduction of point-of-care testing.</a> Clin Lab Haematol. 21 (3), 201-205 (1999).</li><li>WD, Z., 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=Clinical+effect+analysis+of+two+surgical+methods+for+the+treatment+of+ejaculatory+duct+obstruction.">Clinical effect analysis of two surgical methods for the treatment of ejaculatory duct obstruction.</a> Chinese J Androl. 4, 43-45 (2013).</li><li>Halpern, E. J., Hirsch, I. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sonographically+guided+transurethral+laser+incision+of+a+M&#252;llerian+duct+cyst+for+treatment+of+ejaculatory+duct+obstruction.">Sonographically guided transurethral laser incision of a M&#252;llerian duct cyst for treatment of ejaculatory duct obstruction.</a> AJR. Am J Roentgenol. 175 (3), 777-778 (2000).</li><li>Oh, T. H., Seo, I. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+treatment+for+persistent+hematospermia:+a+novel+technique+using+a+holmium+laser.">Endoscopic treatment for persistent hematospermia: a novel technique using a holmium laser.</a> Scand J Surg. 105 (3), 174-177 (2016).</li><li>Lee, J. Y., Diaz, R. R., Choi, Y. D., Cho, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hybrid+method+of+transurethral+resection+of+ejaculatory+ducts+using+holmium:+yttriumaluminium+garnet+laser+on+complete+ejaculatory+duct+obstruction.">Hybrid method of transurethral resection of ejaculatory ducts using holmium: yttriumaluminium garnet laser on complete ejaculatory duct obstruction.</a> Yonsei Med J. 54 (4), 1062-1065 (2013).</li><li>Guo, Y., 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=Role+of+MRI+in+assessment+of+ejaculatory+duct+obstruction.">Role of MRI in assessment of ejaculatory duct obstruction.</a> J Xray Sci Technol. 21 (1), 141-146 (2013).</li><li>Heshmat, S., Lo, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+and+treatment+of+ejaculatory+duct+obstruction+in+infertile+men.">Evaluation and treatment of ejaculatory duct obstruction in infertile men.</a> Can J Urol. 13 (Suppl 1), 18-21 (2006).</li><li>Tu, X. 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=Transurethral+bipolar+plasma+kinetic+resection+of+ejaculatory+duct+for+treatment+of+ejaculatory+duct+obstruction.">Transurethral bipolar plasma kinetic resection of ejaculatory duct for treatment of ejaculatory duct obstruction.</a> J Xray Sci Technol. 21 (2), 293-302 (2013).</li><li>El-Assmy, A., El-Tholoth, H., Abouelkheir, R. T., Abou-El-Ghar, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transurethral+resection+of+ejaculatory+duct+in+infertile+men:+outcome+and+predictors+of+success.">Transurethral resection of ejaculatory duct in infertile men: outcome and predictors of success.</a> Int Urol Nephrol. 44 (6), 1623-1630 (2012).</li><li>Faydaci, G., 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=Effectiveness+of+doxazosin+on+erectile+dysfunction+in+patients+with+lower+urinary+tract+symptoms.">Effectiveness of doxazosin on erectile dysfunction in patients with lower urinary tract symptoms.</a> Int Urol Nephrol. 43 (3), 619-624 (2011).</li><li>McQuaid, J. W., Tanrikut, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ejaculatory+duct+obstruction:+current+diagnosis+and+treatment.">Ejaculatory duct obstruction: current diagnosis and treatment.</a> Curr Urol Rep. 14 (4), 291-297 (2013).</li><li>Liu, Z. Y., 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=Transurethral+seminal+vesiculoscopy+in+the+diagnosis+and+treatment+of+persistent+or+recurrent+hemospermia:+a+single-institution+experience.">Transurethral seminal vesiculoscopy in the diagnosis and treatment of persistent or recurrent hemospermia: a single-institution experience.</a> Asian J Androl. 11 (5), 566-570 (2009).</li><li>Guo, 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=The+application+of+pediatric+ureteroscope+for+seminal+vesiculoscopy.">The application of pediatric ureteroscope for seminal vesiculoscopy.</a> Minim Invasive Surg. 2015, 946147 (2015).</li><li>Xu, B., 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=Novel+methods+for+the+diagnosis+and+treatment+of+ejaculatory+duct+obstruction.">Novel methods for the diagnosis and treatment of ejaculatory duct obstruction.</a> BJU Int. 108 (2), 263-266 (2011).</li><li>Enikeev, D., Shariat, S. F., Taratkin, M., Glybochko, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+changing+role+of+lasers+in+urologic+surgery.">The changing role of lasers in urologic surgery.</a> Curr Opin Urol. 30 (1), 24-29 (2020).</li></ol>

The authors declare that they have no competing interests.

TURED is a primary surgical approach to treat ejaculatory duct obstruction caused by the ejaculatory duct cyst, and its main operation mode is to reveal the ejaculatory duct opening after the excision of cysts with an electric incision to relieve the pressure and dreg the seminal canal11. The study subjects were asked about their medical history during the visit, and all had normal sexual activity frequency (1-2 times per week) and no sexual dysfunction or hematospermia. The preoperative semen exa...

Ejaculatory duct obstruction is a rare disease of the male reproductive system, with a reported incidence of 1%-5%1,2. Ejaculatory duct cysts represent the predominant cause of ejaculatory duct obstruction. Semen examination in typical EDO patients reveals four distinctive characteristics: 1. Semen volume less than 2 mL, with a direct correlation between obstruction severity and decreased volume; 2. Oligospermia, with bilateral complete obstruction resulting in azoospermia; 3. Decreased pH value of semen; 4. Reduced levels of seminal plasma fructose, sometimes even dropping to 0 mM/L3. Male infertility caused by EDO can be treated with surgery and is less effective with conservative treatment4. In the past, the main method was transurethral resection of the ejaculatory duct. Although this approach boasts benefits like reduced trauma and fewer intraoperative complications, the surgical removal of the verumontanum disrupts the normal physiological structure of the distal ejaculatory duct. This, in turn, increases the postoperative risk of complications such as urinary reflux, epididymitis, retrograde ejaculation, and urinary incontinence5. At the same time, heat production during the operation may lead to the injury of the ejaculatory duct, seminal vesicle, and even rectum, and the thermal effect of the electric incision may cause new obstruction6.
The verumontanum stands as a crucial anatomical element within the male reproductive system, ensuring the precise and regulated discharge of semen during ejaculation while also helping to prevent retrograde flow. Whether the disadvantages of TURED can be ameliorated by preserving the seminal caruncle is unclear. Several studies have attempted to utilize laser-assisted endoscopy for the treatment of EDO while preserving verumontanum2,7,8,9. Although the surgical approaches varied, post-operative semen recovery was notably successful with minimal complications. This indicates that preserving the epididymal head may be beneficial. However, the method they used is relatively complex and does not intervene in the healthy ejaculatory duct, which may increase the risk of recurrence. Therefore, we present a simple and effective surgical method.
In this study, the seminal vesiculoscope was guided into the ejaculatory duct cyst on the affected side by a wire guide. Then, the holmium laser was used to enlarge the ejaculatory duct opening on the affected side to ensure that it had a sufficiently large outflow channel.

<table><tbody><tr><td>Camera system</td><td>Karl Storz, Germany</td><td>TC200EN</td><td>Endoscopic camera system</td></tr><tr><td>Fr18 Cathete</td><td>Zhanjiang City Shida Industrial Co., Ltd.</td><td>2660476</td><td>Drainage of urine</td></tr><tr><td>Fr6/7.5 vesiculoscope</td><td>Richard Wolf, germany</td><td>8702.534</td><td>Operative procedure</td></tr><tr><td>iodophor</td><td>Shanghai Likang Disinfectant Hi-Tech Co., Ltd.</td><td>31005102</td><td>Skin disinfection</td></tr><tr><td>Nitinol Guidewire 0.035&quot;</td><td>C. R Bard, Inc. Covington, GA&amp;nbsp;</td><td>150NFS35</td><td>Guide</td></tr><tr><td>Propofol</td><td>Sichuan Kelun Pharmaceutical Research Institute Co., Ltd.</td><td>H20203571</td><td>Induction and maintenance of anesthesia</td></tr><tr><td>Remifentanil</td><td>Yichang Humanwell Pharmaceuticals CO,Ltd.</td><td>H20030200</td><td>Maintenance of anesthesia</td></tr><tr><td>Rocuronium bromide</td><td>Zhejiang Huahai&amp;nbsp; Pharmaceuticals CO,Ltd.</td><td>H20183264</td><td>Induction and maintenance of anesthesia</td></tr><tr><td>Sevoflurane</td><td>Jiangsu Hengrui Pharmaceuticals Co., Ltd.</td><td>H20070172</td><td>Maintenance of anesthesia</td></tr><tr><td>Slimline EZ 200</td><td>LUMENIS, USA</td><td>0642-393-01</td><td>Dissect capsule wall</td></tr><tr><td>Sodium Chloride Physiological Solution</td><td>Hua Ren MEDICAL TECHNOLOGY CO. Ltd.</td><td>H20034093</td><td>Flushing fluid</td></tr><tr><td>Sufentanil</td><td>Yichang Humanwell Pharmaceuticals CO,Ltd.</td><td>H20054171</td><td>Induction and maintenance of anesthesia</td></tr><tr><td>Syringe 50 mL&amp;nbsp;</td><td>Double Pigeon Group Co. Ltd.</td><td>20163141179</td><td>Inject 0.9% sodium chloride solution into the vesiculoscope</td></tr><tr><td>VersaPulse PowerSuite 100W Laser System</td><td>LUMENIS, Germany</td><td>PS.INT.100W</td><td>Provide energy</td></tr></tbody></table>

treatment of ejaculatory duct obstruction by seminal vesiculoscopy assisted flow modification

Transurethral resection of ejaculatory duct (TURED) is a primary surgical approach to treat ejaculatory duct obstruction (EDO) caused by the ejaculatory duct cyst. Intraoperative excision of the verumontanum is usually required to expose the ejaculatory ducts. However, preserving the verumontanum structure allows for a better simulation of normal physiological anatomy. Maintaining the verumontanum may increase the risk of postoperative distal ejaculatory duct scarring, leading to recurrent obstruction or reduced semen volume. Therefore, we attempted a novel technique that preserves the verumontanum, which is relatively easier and safer compared to TURED. The following were the procedural steps: 1. A 6F seminal vesiculoscope was introduced through the external urethral orifice to the vicinity of the verumontanum, locating the opening of the affected-side ejaculatory duct and introducing a guidewire into the cyst. This successful step preserved the verumontanum, maximizing the retention of the anti-reflux mechanism in the distal ejaculatory duct. 2. The holmium laser enlarged the affected-side ejaculatory duct opening to 5 mm, decreasing the likelihood of postoperative closure of the ejaculatory duct opening and simplifying the procedure. 3. A window was created within the cyst to access the contralateral seminal vesicle, and then a holmium laser was used to burn and dilate the opening to 5 mm, redirecting the contralateral ejaculatory duct into the cystic cavity. This modification preserved the opening of the healthy-side ejaculatory duct and provided a new outflow passage for semen, reducing the risk of decreased semen volume postoperatively. The patients experienced no complications postoperatively, had shorter hospital stays, and showed improvement in semen volume. Hence, this surgical approach is simple yet effective.

A total of 5 patients were enrolled in this study, ranging in age from 27 to 34 years (median 31 years), with a disease course of 6 to 15 months (mean 9 months). Follow-up was 12 to 48 months (mean 24.8 months). All patients successfully completed the operation. The average operation time was 26 min and the average hospital stay was 2 days. All 5 cases had unilateral EDO and contralateral seminal vesicle dilatation. The demographic information, incorporating preoperative and postoperative data, pertaining to the patients...

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Author Spotlight: Advanced Treatment of Seminal Duct Blockage Employing Endoscopy-Mediated Semen Channel Refluviation 

This protocol introduces the clinical application of seminal vesicle endoscopy combined with holmium laser in the treatment of ejaculatory duct obstruction caused by ejaculatory duct cyst.

Treatment of Ejaculatory Duct Obstruction by Seminal Vesiculoscopy Assisted Flow Modification

Transurethral resection of ejaculatory duct (TURED) is a primary surgical approach to treat ejaculatory duct obstruction (EDO) caused by the ejaculatory ...

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2.2K Views.  The Second Affiliated Hospital of Kunming Medical University. This protocol introduces the clinical application of seminal vesicle endoscopy combined with holmium laser in the treatment of ejaculatory duct obstruction caused by ejaculatory duct cyst.

Video: Author Spotlight: Advanced Treatment of Seminal Duct Blockage Employing Endoscopy-Mediated Semen Channel Refluviation 

Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision

Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base for dental restorations. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. A specific scanning protocol was tested to scan original tooth surface from dental impressions. Also, different model materials were verified. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 &#177; 1.1 &#181;m for trueness and 1.6 &#177; 0.6 &#181;m for precision in case of full arch scans. Current dental impression methods showed much higher deviations (trueness: 20.4 &#177; 2.2 &#181;m, precision: 12.5 &#177; 2.5 &#181;m) than the internal scanning accuracy of the reference scanner. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. The reference scanner can be used to measure differences for a lot of dental research fields. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes.

Accuracy is a major demand in dental medicine. To verify accuracy, reference scanners are needed. This article presents a new reference scanner with an adjusted scanning method to acquire a broad variety of dental morphologies with high trueness and precision.

Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base ...

Bile Duct Ligation in Mice: Induction of Inflammatory Liver Injury and Fibrosis by Obstructive Cholestasis

In most vertebrates, the liver produces bile that is necessary to emulsify absorbed fats and enable the digestion of lipids in the small intestine as well as to excrete bilirubin and other metabolic products. In the liver, the experimental obstruction of the extrahepatic biliary system initiates a complex cascade of pathological events that leads to cholestasis and inflammation resulting in a strong fibrotic reaction originating from the periportal fields. Therefore, surgical ligation of the common bile duct has become the most commonly used model to induce obstructive cholestatic injury in rodents and to study the molecular and cellular events that underlie these pathophysiological mechanisms induced by inappropriate bile flow. In recent years, different surgical techniques have been described that either allow reconnection or reanastomosis after bile duct ligation (BDL), e.g., partial BDL, or other microsurgical methods for specific research questions. However, the most frequently used model is the complete obstruction of the common bile duct that induces a strong fibrotic response after 21 to 28 days. The mortality rate can be high due to infectious complications or technical inaccuracies. Here we provide a detailed surgical procedure for the BDL model in mice that induce a highly reproducible fibrotic response in accordance to the 3R rule for animal welfare postulated by Russel and Burch in 1959.

Disruption of bile flow results in severe inflammatory cholestatic liver injury with a characteristic time-dependent sequence of morphological alterations. Here we present a protocol for the surgical ligation of the common bile duct in mice that allows to induce a strong fibrotic response after 21 to 28 days.

In most vertebrates, the liver produces bile that is necessary to emulsify absorbed fats and enable the digestion of lipids in the small intestine as well ...

A Murine Model of Irreversible and Reversible Unilateral Ureteric Obstruction

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive nephropathy induced by unilateral ureteric obstruction (UUO), which can either be irreversible (UUO) or reversible (R-UUO). In the irreversible UUO model, the ureter may be obstructed for variable periods of time in order to induce increasingly severe renal inflammation and interstitial fibrotic scarring. In the reversible R-UUO model the ureter is obstructed to induce hydronephrosis, tubular dilation and inflammation. After a suitable period of time the ureteric obstruction is then surgically reversed by anastomosis of the severed previously obstructed ureter to the bladder in order to allow complete decompression of the kidney and restoration of urinary flow to the bladder. The irreversible UUO model has been used to investigate various aspects of renal inflammation and scarring including the pathogenesis of disease and the testing of potential anti-inflammatory or anti-fibrotic therapies. The more challenging model of R-UUO has been used by some investigators and does offer significant research potential as it allows the study of inflammatory and immune processes and tissue remodeling in an injured and scarred kidney following the removal of the injurious stimulus. As a result, the R-UUO model offers investigators the opportunity to explore the resolution of kidney inflammation together with key aspects of tissue repair. These experimental models are of relevance to human disease as patients often present with obstruction of the renal tract that requires decompression and are commonly left with significant residual kidney impairment that has no current treatment options and may lead to eventual end stage kidney failure.

The murine model of irreversible unilateral ureteric obstruction (UUO) is presented together with the model of reversible UUO in which the ureteric obstruction is relieved by anastomosis of the severed ureter into the bladder. These models enable the study of renal inflammation and scarring as well as tissue remodeling.

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive ...

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.

This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings.

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control ...

Vessel-Sparing Microsurgical Longitudinal Intussusception Vasoepididymostomy to Treat Epididymal Obstructive Azoospermia

The epididymis is a common site of obstruction in obstructive azoospermia (OA). Vasoepididymostomy has become an important method for the treatment of epididymal OA since 2000. There are two challenges in classic microscopic vasoepididymostomy. First, anastomosis of the vas deferens and epididymis is performed with double-needle sutures. However, there is a lack of good-quality and cost-effective double-needle sutures in China, which leads to increased difficulty and poor success rates of anastomosis. Second, the separation of the vas deferens does not retain vasculature, although the vas deferens vasculature plays an important role in the blood supply to the vas deferens, epididymis, and testis. This affects the blood supply to the anastomotic area and epididymis.
Therefore, this team has made innovative improvements to address these problems. Good-quality, cost-effective, single-needle sutures, which are easy to purchase in China and other countries, were used in microsurgical longitudinal intussusception vasoepididymostomy. This can optimize the operation procedure and shorten the operation time while ensuring the success rate of the anastomosis. The surgical method of preserving the vas deferens vessels was innovatively proposed because the etiology of epididymal OA is mostly inflammatory in China. The protection of the blood supply to the vas deferens and epididymis is maximized using microsurgical forceps to separate and protect the vasculature. Patency reached 81.7% in the postoperative follow-up, indicating a better surgical treatment effect.

The present protocol describes a vessel-sparing, longitudinal intussusception vasoepididymostomy using readily available single-needle sutures in China, a safe and effective procedure, which may improve patients' patency and natural pregnancy rates.

The epididymis is a common site of obstruction in obstructive azoospermia (OA). Vasoepididymostomy has become an important method for the treatment of ...

A Modified Vessel-Sparing Microsurgical Vasoepididymostomy

Microsurgical vasoepididymostomy (MVE) is the main surgical treatment for epididymal obstruction. The vasal vessels are ligated during MVE. However, preserving the vasal vessels during MVE might better simulate the normal physiological structure and be meaningful for patients who have undergone varicocelectomy. Nevertheless, preserving the vasal vessels might elevate the risk of increasing the tension of anastomosis, affecting the patency rate and leading to delayed postoperative bleeding. Therefore, we developed a novel vessel-sparing MVE to make it safer. Here is a summary of the improvements to the procedure. 1) The retrograde dissociation of the vasal vessels on the proximal testicular side was adopted as the main method, and the anterograde dissociation of the vasal vessels on the distal testicular side was adopted as a supplement to dissociate the vasal vessels to be preserved. This improvement ensures the blood supply to the vas deferens that will be used for anastomosis and also provides longer vasal vessels, which reduces the tension of anastomosis. 2) By fixing the vas deferens to be anastomosed and the broken end of the vas deferens, the free vasal vessels get fixed, which resolves the problem of transmission of vas tension to the vasal vessels and reduces the risk of vasal vessel hemorrhage. 3) Dissociation of the vas deferens after opening the tunica vaginalis increases the mobilization of the vas deferens, which also makes the new procedure easier to complete. The evaluation of the outcomes of this new procedure showed that no significant postoperative complications occurred in the patients, and the patency rate was no different from that of the conventional procedure. Therefore, this new, improved procedure can be considered safe, with satisfactory postoperative results.

Here, we present a protocol to preserve the vasal vessels in microsurgical vasoepididymostomy. The surgical security is enhanced by preserving the vasal vessels using a retrograde-anterograde dissociation and fixing the vasal vessels.

Microsurgical vasoepididymostomy (MVE) is the main surgical treatment for epididymal obstruction. The vasal vessels are ligated during MVE. However, ...

Clinical Application of 24 G Cannula Needle and 3-0 Polypropylene Suture in Vas Deferens Exploration

The goal of this article is to present the application of a 24 G cannula and 3-0 polypropylene suture as a simple method for the exploration of the vas deferens. During the exploration of the vas deferens, a 24 G cannula needle was used to puncture it. The fluid in the smear confirmed the presence of sperm, to determine whether or not there was concomitant obstruction at the junction of the epididymis and the vas deferens. Then, a 3-0 polypropylene suture (this suture specification has the advantages of a smooth surface, robust quality, and can be passed through a 24 G cannula needle) was passed through the cannula needle to probe the location of the obstructed site. With this technique, exploration of the vas deferens could be more targeted and accurate.

This protocol presents the clinical application of a 24 G cannula and 3-0 polypropylene suture as a simple and effective method for the exploration of the vas deferens.

The goal of this article is to present the application of a 24 G cannula and 3-0 polypropylene suture as a simple method for the exploration of the vas ...

Combination of High Ligation and Intraoperative Embolization using Polidocanol for Treatment of Varicoceles

Varicoceles are dilated veins within the pampiniform plexus and are relatively common in the general male population. The spermatic vein has many branches in the scrotal segment and then gradually merges into 1-2 trunks after passing through the internal inguinal ring. The key to a successful varicocelectomy is to ligate all the spermatic veins while protecting the testicular arteries and spermatic lymphatic vessels from damage. The small veins, including the branches of spermatic veins and collateral veins, are easily missed for ligation during conventional high ligation of varicocele, which has been suggested as a major cause of postoperative recurrence. Although microsurgery effectively reduces the risk of missing ligation of the spermatic veins during surgery, it has several shortcomings, such as long operation time and a steep learning curve. More importantly, this technique is difficult to carry out in primary hospitals due to the requirement of specialized equipment. Therefore, an attempt to modify the traditional high ligation aiming to reduce the postoperative recurrence rate has been carried out here. The protocol here combines traditional high ligation with intraoperative embolization to seal off the branches of the spermatic vein and collateral veins. We rapidly injected foamed sclerosant into the internal spermatic vein under direct observation after separation of the spermatic vein and then ligated all the veins. The foamed sclerosant through the varicose vein hampers endothelial cell growth, promotes the growth of thrombus and fibrosis, and ultimately forms fibrous streaks that permanently fill the venous. The results showed a more satisfactory effect on reducing the postoperative recurrence rate compared with traditional high ligation. Since this protocol is simple to carry out and has better results in reducing the recurrence rate, this can be an alternative surgical method for the treatment of varicocele, especially in primary hospitals.

To reduce the postoperative recurrence rate of varicocelectomy, we combined high ligation of varicocele with intraoperative embolization. We injected polidocanol from the spermatic vein during surgery to embolize the branches of the spermatic vein and collateral veins. This is an alternative surgical method for the treatment of varicocele.

Varicoceles are dilated veins within the pampiniform plexus and are relatively common in the general male population. The spermatic vein has many branches ...

Bilateral Spermatic Nerve Blocks and Vasectomy Procedures in Males

Optimizing the Modified No-Scalpel Vasectomy Technique

No-scalpel vasectomy (NSV) is a commonly used contraceptive method for males. In previous applications of this surgical method, issues such as knot detachment and postoperative recanalization resulted in a reduced contraceptive success rate after vasectomy. This new technique innovatively modifies the ligation procedure during NSV to address knot detachment and postoperative recanalization. Two ligations of the testicular end of the vas deferens and one ligation of the abdominal end are completed before transection of the vas deferens. A fourth ligation of the abdominal end is performed using the suture tails of the third ligature of the testicular end after transection of the vas deferens. The fifth ligation of the abdominal end is performed using the suture tails of the first ligature of the testicular end. These modifications strengthen the ligations and reduce the postoperative recanalization rate. Additionally, the two stumps are gathered together, creating better conditions for a possible vasovasostomy in the future, thereby achieving overall better outcomes with vasectomy.

A modified no-scalpel vasectomy technique reduces the postoperative recanalization rate. This protocol describes a modified no-scalpel vasectomy technique that can reduce the postoperative recanalization rate.

No-scalpel vasectomy (NSV) is a commonly used contraceptive method for males. In previous applications of this surgical method, issues such as knot ...

Urethroplasty with Pedicled Tunica Vaginalis for the Treatment of Long-segment Anterior Urethral Stricture Caused by Lichen Sclerosus of Glans Penis

Urethroplasty for the management of long-segment urethral strictures associated with lichen sclerosus presents considerable clinical challenges. Oral mucosal grafts are commonly employed but are vulnerable to posttransplantation infection and recurrent stricture formation. Furthermore, the necessity for anesthesia and oral graft harvesting restricts their application in primary healthcare settings.
The single layer of flattened epithelium of the tunica vaginalis can serve as a potential alternative to oral mucosa. Animal experiments have demonstrated that the tunica vaginalis can readily form a tight connection with the multilayered urothelium of the urethra. Utilizing the tunica vaginalis as a scaffold for urethral re-epithelialization may help reduce the risk of recurrence of urethral stricture after surgery. Over a 19 year period, pedicled tunica vaginalis urethroplasty has been used for successfully treating 86 cases. 
The surgical procedure involves dorsally incising the urethral stricture segment, then covering it with a pedicled tunica vaginalis patch followed by suturing. Postoperatively, the pedicled tunica vaginalis graft exhibits good vascularization and take rate, facilitating urethral re-epithelialization. The surgical procedure is conducted in a sterile environment to mitigate the potential for infectious complications. Moreover, the operation can be executed under spinal anesthesia, which facilitates its implementation in primary healthcare settings.

This article introduces a surgical method using a pedicled tunica vaginalis to treat long-segment urethral stricture resulting from lichen sclerosus. The tunica vaginalis is an excellent substitute for the urethra, leading to quick postoperative recovery for patients.

Urethroplasty for the management of long-segment urethral strictures associated with lichen sclerosus presents considerable clinical challenges. Oral ...