Name: Video: A Case Series of Successful Abdominal Closure Utilizing a Novel Technique Combining a Mechanical Closure System with a Biologic Xenograft that Accelerates Wound Healing
Uploaded: 2019-07-04T13:00:00.000+00:00
Duration: 20 s

The authors have no acknowledgements.

1. Installation of Dynamic Tissue System
<ol>
	<li>Exclude if there is hemodynamic instability, a need for further abdominal washouts, or a concern for intraabdominal sepsis.
	<ol>
		<li>If an ostomy exists, trim the ostomy wafer to make as narrow as possible and outline on abdominal skin. Cover ostomy with 4x4 and secure in place with adhesive transparent film dressing.</li>
		<li>Apply antimicrobial betadine impregnated adhesive drape to the skin of the abdomen widely, covering the operating field.</li>
		<li>Wash the abdomen out with at least 2 L of 40.5&#176; C normal saline.</li>
		<li>Measure and record the myofascial gap (MFG), visceral extrusion (VE), and the length of incision in centimeters for documentation of progress on the operative note.</li>
		<li>Mark the skin of the anterior abdominal wall 5 cm laterally from medial fascial edge to create an ellipse around the midline wound.</li>
		<li>Place the elastomer buttons side by side on the ellipse created in step 1.1.5. with the &#8220;U&#8221; of the elastomer at the 5 cm ellipse demarcation around the midline wound. This will assure 3 cm spacing as recommended.</li>
		<li>Create superficial thickness dermotomies with an 11 blade.</li>
		<li>Pull the elastomer through the abdominal wall using the cannulator.</li>
		<li>Repeat the same steps on the opposite side. This time pull the elastomer across the myofascial gap and secure both ends with a hemostat.</li>
		<li>Loosely attach the elastomer bands to the elastomer buttons. Do not tighten elastomer bands.</li>
		<li>Attach elastomer adhesion stickers on the button tails.</li>
		<li>Perform osteopathic maneuvers throughout installation. This is performed with two people standing on either side of the patient. Apply bimanual forces in the flank area, gently massaging towards the midline and create circular motions synchronized with the other operator first towards the head and then creating circular motions towards the feet.</li>
	</ol>
	</li>
</ol>
2. Silicone Visceral Protector Inserted
<ol>
	<li>Insert silicone visceral protector midline over abdominal viscera, taking care to protect any ostomies (Figure 3).</li>
	<li>Envelop the abdominal viscera with silicone visceral protector down to each paracolic gutter.</li>
	<li>Create necessary cut outs in the visceral protector with scissors to protect the ostomies.</li>
	<li>Place elastomer retainer in the midline on top of visceral protector and evenly space elastomer bands into the retainer (trim to size).</li>
	<li>Adjust elastomer bands slowly in between osteopathic maneuvers.</li>
	<li>Stop elastomer adjustments when tension hashmarks across the MFG is 1.5 &#8211; 2x stretch.</li>
	<li>Record the MFG and VE with a ruler in centimeters at the start, install, and completion (Figure 4).</li>
</ol>
3. Installation of Negative Pressure Wound Therapy Device
<ol>
	<li>Make NPWT device sponge as thing as possible and place in the midline above the elastomer retainer (Figure 5).</li>
	<li>Cover with vacuum drape tape and apply the negative pressure device with continuous suction at -100 mmHg.</li>
	<li>Perform osteopathic maneuver a few more times.</li>
</ol>
4. Elastomer Adjustment
<ol>
	<li>Bring the patient back to operating room, or if your facility has the capability to perform in ICU, periodically. First elastomer adjustment can be 2 &#8211; 5 days after installation.</li>
	<li>Remove the NPWT device overlying the midline wound with scissors, taking care to leave the adhesive iodine drape on the skin intact.</li>
	<li>Prep the abdomen widely including the elastomers in place with 4% chlorhexidine gluconate.</li>
	<li>Perform osteopathic maneuvers intermittently throughout procedure. See step 1.1.12. for details.</li>
	<li>Record the MFG and myofascial apposition (Figure 6).</li>
	<li>Irrigate the midline wound with at least 2 L of 40.5&#176; C normal saline, taking care not to spill water on the DTS or the antimicrobial iodine impregnated adhesive drape.</li>
	<li>Adjust elastomers by releasing the elastomer from the anchor and pulling each elastomer laterally, away from the midline.</li>
	<li>Reapply the black sponge NPWT device.</li>
</ol>
5. Fascial Closure
<ol>
	<li>Bring the patient back to the operating room. Prep widely.</li>
	<li>Remove the elastomer retainer.</li>
	<li>Remove the visceral protector and irrigate the abdominal cavity with at least 2 L of normal saline.</li>
	<li>Close the fascia in a bi-directional fashion utilizing a Smead-Jones technique and a #2 vicryl suture on a TP1 needle.</li>
	<li>Irrigate and dry the midline wound.</li>
	<li>Apply PUBM micromatrix powder to the midline wound and evenly distribute the powder so that the newly created linea alba is covered in PUBM micromatrix.</li>
	<li>Hydrate a two-layer, 10x15 cm, PUBM wound sheet and delaminate so there are 2 single sheets. Apply the sheets on top of the powder to cover the entire midline wound surface (Figure 7).</li>
	<li>Appose skin edge with strips of vac drape tape (Figure 8).</li>
</ol>

<ol>
	<li>Kirkpatrick, A. W., 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=Update+from+the+Abdominal+Compartment+Society+(WSACS)+on+intra-abdominal+hypertension+and+abdominal+compartment+syndrome:+past,+present,+and+future+beyond+Banff+2017.">Update from the Abdominal Compartment Society (WSACS) on intra-abdominal hypertension and abdominal compartment syndrome: past, present, and future beyond Banff 2017.</a> Anaesthesiology Intensive Therapy. 49 (2), 83-87 (2017).</li><li>Yetisir, F., Sarer, A. E., Acar, H. Z., Aygar, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+Closure+of+61+Open+Abdomen+Patients+Based+on+an+Algorithm.">Delayed Closure of 61 Open Abdomen Patients Based on an Algorithm.</a> Indian Journal of Surgery. 79 (1), 38-44 (2017).</li><li>Ribeiro Junior, M. 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=Open+abdomen+in+gastrointestinal+surgery:+Which+technique+is+the+best+for+temporary+closure+during+damage+control?.">Open abdomen in gastrointestinal surgery: Which technique is the best for temporary closure during damage control?.</a> World Journal of Gastrointestinal Surgery. 8 (8), 590-597 (2016).</li><li>Karakose, 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=Bogota+Bag+Use+in+Planned+Re-Laparotomies.">Bogota Bag Use in Planned Re-Laparotomies.</a> Medical Science Monitor. 22, 2900-2904 (2016).</li><li>Lassalle, S., Chechin, C., de la Forge, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+cleansing+technique+for+complex+wounds.">A new cleansing technique for complex wounds.</a> Soins. 62 (814), 12-15 (2017).</li><li>Strang, S. G., Van Lieshout, E. M., Van Waes, O. J., Verhofstad, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+and+mortality+of+abdominal+compartment+syndrome+in+severely+injured+patients:+A+systematic+review.">Prevalence and mortality of abdominal compartment syndrome in severely injured patients: A systematic review.</a> The Journal of Trauma and Acute Care Surgery. 81 (3), 585-592 (2016).</li><li>Bressan, A. K., Ball, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intra-abdominal+hypertension+and+abdominal+compartment+syndrome+in+acute+pancreatitis,+hepato-pancreato-biliary+operations+and+liver+transplantation.">Intra-abdominal hypertension and abdominal compartment syndrome in acute pancreatitis, hepato-pancreato-biliary operations and liver transplantation.</a> Anaesthesiology Intensive Therapy. 49 (2), 159-166 (2017).</li><li>Muresan, 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=How+much+does+decompressive+laparotomy+reduce+the+mortality+rate+in+primary+abdominal+compartment+syndrome?:+A+single-center+prospective+study+on+66+patients.">How much does decompressive laparotomy reduce the mortality rate in primary abdominal compartment syndrome?: A single-center prospective study on 66 patients.</a> Medicine (Baltimore). 96 (5), e6006 (2017).</li><li>Coccolini, F., 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=IROA:+International+Register+of+Open+Abdomen,+preliminary+results.">IROA: International Register of Open Abdomen, preliminary results.</a> World Journal of Emergency Surgery. 12, 8 (2017).</li><li>Lecheminant, J., Field, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Porcine+urinary+bladder+matrix:+a+retrospective+study+and+establishment+of+protocol.">Porcine urinary bladder matrix: a retrospective study and establishment of protocol.</a> Journal of Wound Care. 21 (10), 482 (2012).</li><li>Coccolini, F., 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=IROA:+International+Register+of+Open+Abdomen,+preliminary+results.">IROA: International Register of Open Abdomen, preliminary results.</a> World Journal of Emergency Surgery. 12, 8 (2017).</li><li>Muturi, A., Ndaguatha, P., Ojuka, D., Kibet, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+and+predictors+of+intra-abdominal+hypertension+and+compartment+syndrome+in+surgical+patients+in+critical+care+units+at+Kenyatta+National+Hospital.">Prevalence and predictors of intra-abdominal hypertension and compartment syndrome in surgical patients in critical care units at Kenyatta National Hospital.</a> BMC Emergency Medicine. 17 (1), (2017).</li><li>Okullo, 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=The+Abdominal+Reapproximation+Anchor+Device.">The Abdominal Reapproximation Anchor Device.</a> Surgical Innovation. 24 (1), 49-54 (2017).</li><li>Yetisir, F., Sarer, A. 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Dr. Catherine Ronaghan is an ACell&#160;cadaver lab proctor and speaker. The rest of the authors have nothing to disclose.

The most critical step of the protocol for closing a complex abdominal wound is performing osteopathic maneuvers before elastomer placement, after elastomer placement, and before and after elastomer adjustments. In addition, we perform osteopathic maneuvers on these patients after surgery three times a day, for at least five days. Our approach describes the use of osteopathic maneuver prior and after elastomer adjustments. The anecdotal observation has been that these maneuvers aid in fascial approximation, by facilitati...

The increasing prevalence of abdominal compartment syndrome (ACS) has led to an emergence of various temporary abdominal closure (TAC) techniques1. TAC is performed to prevent evisceration, assist in the removal of unwanted intraperitoneal fluid, minimize intra-abdominal complications, and expedite the closure of the abdominal cavity2. Closure of an open abdomen facilitates restoration of normal physiology in the patient3. Prolonged duration of an open abdomen results in complications&#160;such as fistula formation and an inability to close the abdomen4. There are several methods to achieve final closure of an open abdomen.
The simplest way to temporarily close an abdomen is by using towel clips to close the skin5. One of the most commonly used and studied abdominal closure techniques is negative pressure wound therapy (NPWT)5. For the NPWT, a nonadherent barrier to protect the intraabdominal contents is applied followed by a moisture-absorbing sponge-like material,&#160;an outermost adhesive layer to sure the dressing in place, and a negative pressure mechanism6. A Bogota bag can also be used for temporary closure of an open abdomen. A Bogota bag is an empty intravenous fluid bag cut in half and sutured to&#160;skin edges7. NPWT and the Bogota bag closure are two temporizing measures that facilitate delayed primary closure of the abdominal cavity7.
Once the abdomen is deemed ready for closure, different closure methods can be utilized. The simplest way is to apply a split-thickness graft over the omentum once it has formed healthy granulation tissue. If the wound is not contaminated, a nonabsorbable synthetic sheet may be used to bridge the fascial edges8. If the fascial gap is less than 14-20 cm in maximal diameter, component separation of the rectus sheath can be performed9.
Some abdominal closure techniques allow for gradual reapproximation of the fascial edges and eventual primary closure10. A Wittmann patch consists of two opposing Velcro sheets that are sutured to each fascial edge11. The opposing sheets are then fastened together in the midline. This mechanism allows easy re-entry into the abdomen and adjustment for abdominal compartment pressures. Additionally, this can&#160;provide midline traction on the fascial edges that can prevent retraction of the fascial edges and also facilitate primary closure of the fascia.
Alternatively, a DTS is available and is part of the technique described in this paper. The described DTS is composed to a silicone viscera protector that is applied over abdominal contents to prevent adhesions and adherence of viscera to the abdominal wall. Adjustable elastomers then penetrate the full abdominal wall thickness on each side and provide medializing dynamic tension, allowing relaxation of the flat muscles (obliques and transversus abdominus). This allows medialization of the rectus myofascial units (Figure 1). A product composed of porcine urinary bladder extracellular matrix can be placed in the subcutaneous space once primary myofascial closure is achieved (Figure 2). Porcine xenograft placement in the subcutaneous space augments and expedites wound healing through angiogenesis, innervation, modulation of the inflammatory response, and resistance to infection12.
In this study, we describe a novel technique of primary abdominal closure following abdominal compartment syndrome utilizing a dynamic closure system and a biologic xenograft. At our level 1&#160;trauma and acute care center, abdominal compartment syndrome is a common diagnosis. Prior to utilization of this novel method, most catastrophic open abdomens were not amenable to primary closure and a skin graft was placed over the viscera or bridging&#160;mesh. Since the adoption of this method in May of 2016, we have closed 100% of open abdomens due to abdominal compartment syndrome in a high-risk&#160;population (average BMI 40.45, SD 9.83) (Table 1).

<table><tbody><tr><td>ABRA Abdominal Wall Closure Set</td><td>Southmedic</td><td>CWK08 Abdominal</td><td></td></tr><tr><td>3M Ioban 2 Antimicrobial Incise Drape</td><td>3M</td><td>6651EZ</td><td></td></tr><tr><td>MicroMatrix Micronized Particles 200 mg</td><td>ACell</td><td>MM0200</td><td></td></tr><tr><td>Cytal Wound Matrix 2-Layer 10 x 15 cm</td><td>ACell</td><td>WSM1015</td><td></td></tr><tr><td>Negative Pressure Therapy System</td><td>KCI</td><td>09-03-193.ABT.IE</td><td></td></tr></tbody></table>

a case series of successful abdominal closure utilizing a novel technique combining a mechanical closure system with a biologic xenograft that accelerates wound healing

In the acute setting, once intra-abdominal injuries have been addressed, the next great hurdle is restoring a functional and intact abdominal compartment. The short and long-term consequences of living with a chronically open abdominal compartment include pulmonary, musculoskeletal, gastrointestinal, and emotional disability. The closure of catastrophic open abdomens presents a challenge to the surgeon. We present a technique utilizing a mechanical abdominal closure device in conjunction with biologic xenograft in closing complex open abdomens. This technique offers another option for definitive fascial closure and accelerated wound healing in this difficult patient population. The dynamic tissue system (DTS) is installed after control of original intraabdominal pathology. A porcine urinary bladder matrix (PUBM) is then placed in the subcutaneous space once fascial closure is achieved. Overall, primary myofascial closure was achieved in 100% of patients at a mean of 9.36 days.

We have analyzed a total of 11 patients so far with catastrophic open abdomens. Primary myofascial closure was achieved at a mean of 9.36 days. We had 0% surgical site infections (SSI) and achieved 100% primary myofascial closure. No enteroatmospheric fistula resulted in this technique, unless present prior to this DTS and xenograft approach. Since May 2016, zero open abdomens were left open or covered with a skin graft (Figure 9).
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Watch this Scientific Journal Video about A Case Series of Successful Abdominal Closure Utilizing a Novel Technique Combining a Mechanical Closure System with a Biologic Xenograft that Accelerates Wou

A Case Series of Successful Abdominal Closure Utilizing a Novel Technique Combining a Mechanical Closure System with a Biologic Xenograft that Accelerates Wound Healing

Closure of catastrophic open abdominal wounds presents a challenge to the surgeon. We present a surgical technique utilizing a combination of mechanical and biologic xenograft closure systems in closing complex open abdominal wounds. This technique offers another option to the surgeon for definitive fascial closure and accelerated wound healing.

In the acute setting, once intra-abdominal injuries have been addressed, the next great hurdle is restoring a functional and intact abdominal compartment. ...

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51.2K Views.  Texas Tech University Health Sciences Center. Closure of catastrophic open abdominal wounds presents a challenge to the surgeon. We present a surgical technique utilizing a combination of mechanical and biologic xenograft closure systems in closing complex open abdominal wounds. This technique offers another option to the surgeon for definitive fascial closure and accelerated wound healing.

Video: A Case Series of Successful Abdominal Closure Utilizing a Novel Technique Combining a Mechanical Closure System with a Biologic Xenograft that Accelerates Wound Healing

A Full Skin Defect Model to Evaluate Vascularization of Biomaterials In Vivo

Insufficient vascularization is considered to be one of the main factors limiting the clinical success of tissue-engineered constructs. In order to evaluate new strategies that aim at improving vascularization, reliable methods are required to make the in-growth of new blood vessels into bio-artificial scaffolds visible and quantify the results. Over the past couple of years, our group has introduced a full skin defect model that enables the direct visualization of blood vessels by transillumination and provides the possibility of quantification through digital segmentation. In this model, one surgically creates full skin defects in the back of mice and replaces them with the material tested. Molecules or cells of interest can also be incorporated in such materials to study their potential effect. After an observation time of one&#8217;s own choice, materials are explanted for evaluation. Bilateral wounds provide the possibility of making internal comparisons that minimize artifacts among individuals as well as of decreasing the number of animals needed for the study. In comparison to other approaches, our method offers a simple, reliable and cost effective analysis. We have implemented this model as a routine tool to perform high-resolution screening when testing vascularization of different biomaterials and bio-activation approaches.

A Full Skin Defect Model to Evaluate Vascularization of Biomaterials In Vivo

Vascularization is key to approaches in successful tissue engineering. Therefore, reliable technologies are required to evaluate the development of vascular networks in tissue-constructs. Here we present a simple and cost-effective method to visualize and quantify vascularization in vivo.

Insufficient vascularization is considered to be one of the main factors limiting the clinical success of tissue-engineered constructs. In order to ...

Bioengineering

Engineered Vascularized Muscle Flap

One of the main factors limiting the thickness of a tissue construct and its consequential viability and applicability in vivo, is the control of oxygen supply to the cell microenvironment, as passive diffusion is limited to a very thin layer. Although various materials have been described to restore the integrity of full-thickness defects of the abdominal wall, no material has yet proved to be optimal, due to low graft vascularization, tissue rejection, infection, or inadequate mechanical properties. This protocol describes a means of engineering a fully vascularized flap, with a thickness relevant for muscle tissue reconstruction. Cell-embedded poly L-lactic acid/poly lactic-co-glycolic acid constructs are implanted around the mouse femoral artery and vein and maintained in vivo for a period of one or two weeks. The vascularized graft is then transferred as a flap towards a full thickness defect made in the abdomen. This technique replaces the need for autologous tissue sacrifications and may enable the use of in vitro engineered vascularized flaps in many surgical applications.

To date, thick tissue defects are typically reconstructed by applying autologous tissue flaps or engineered tissues. In this protocol, we present a new method for engineering vascularized tissue flap bearing an autologous pedicle, to serve as a substitute to autologous flaps.

One of the main factors limiting the thickness of a tissue construct and its consequential viability and applicability in vivo, is the control of oxygen ...

Minced Tissue in Compressed Collagen: A Cell-containing Biotransplant for Single-staged Reconstructive Repair

Conventional techniques for cell expansion and transplantation of autologous cells for tissue engineering purposes can take place in specially equipped human cell culture facilities. These methods include isolation of cells in single cell suspension and several laborious and time-consuming events before transplantation back to the patient. Previous studies suggest that the body itself could be used as a bioreactor for cell expansion and regeneration of tissue in order to minimize ex vivo manipulations of tissues and cells before transplanting to the patient. The aim of this study was to demonstrate a method for tissue harvesting, isolation of continuous epithelium, mincing of the epithelium into small pieces and incorporating them into a three-layered biomaterial. The three-layered biomaterial then served as a delivery vehicle, to allow surgical handling, exchange of nutrition across the transplant, and a controlled degradation. The biomaterial consisted of two outer layers of collagen and a core of a mechanically stable and slowly degradable polymer. The minced epithelium was incorporated into one of the collagen layers before transplantation. By mincing the epithelial tissue into small pieces, the pieces could be spread and thereby the propagation of cells was stimulated. After the initial take of the transplants, cell expansion and reorganization would take place and extracellular matrix mature to allow ingrowth of capillaries and nerves and further maturation of the extracellular matrix. The technique minimizes ex vivo manipulations and allow cell harvesting, preparation of autograft, and transplantation to the patient as a simple one-stage intervention. In the future, tissue expansion could be initiated around a 3D mold inside the body itself, according to the specific needs of the patient. Additionally, the technique could be performed in an ordinary surgical setting without the need for sophisticated cell culturing facilities.

Tissue engineering often includes in vitro expansion in order to create autografts for tissue regeneration. In this study a method for tissue expansion, regeneration, and reconstruction in vivo was developed in order to minimize the processing of cells and biological materials outside the body.

Conventional techniques for cell expansion and transplantation of autologous cells for tissue engineering purposes can take place in specially equipped ...

Use of a Rat Model to Study Ventral Abdominal Hernia Repair

Ventral abdominal hernia is a relatively common clinical condition that sometimes requires herniorraphy (surgical repair). The repair of ventral abdominal hernia typically requires implantation of a material to serve as a mechanical bridge across the defect in the abdominal wall. Biomaterials, such as porcine small intestinal submucosa (SIS), also serve as a lattice for cell growth into the implant and can naturally incorporate into the host tissue. Development of such repair materials benefits from use of animal models in which experimental abdominal wall defects are easily created and are amenable to repair in a reproducible fashion. The method offered here describes surgical creation and repair of ventral abdominal hernia in a rat model. When SIS is used to repair an experimental ventral abdominal hernia in this model, it is rapidly incorporated into host tissue within 28 days of implantation. Histologically, incorporation of their implanted material into host tissue is characterized by a robust fibrovascular response. Future refinements and applications of the rat abdominal hernia model may likely involve diabetic and/or obese animals as a means to more closely mimic common co-morbidities of man.

This manuscript describes methods associated with creation and repair of a ventral abdominal wall defect (hernia). This model can be used to study repair strategies such as those that use implanted materials. In this manuscript, repair of the experimental hernia with porcine small intestinal submucosa is presented as an example.

Ventral abdominal hernia is a relatively common clinical condition that sometimes requires herniorraphy (surgical repair). The repair of ventral abdominal ...

Tissue Characterization after a New Disaggregation Method for Skin Micro-Grafts Generation

Several new methods have been developed in the field of biotechnology to obtain autologous cellular suspensions during surgery, in order to provide one step treatments for acute and chronic skin lesions. Moreover, the management of chronic but also acute wounds resulting from trauma, diabetes, infections and other causes, remains challenging. In this study we describe a new method to create autologous micro-grafts from cutaneous tissue of a single patient and their clinical application. Moreover, in vitro biological characterization of cutaneous tissue derived from skin, de-epidermized dermis (Ded) and dermis of multi-organ and/or multi-tissue donors was also performed. All tissues were disaggregated by this new protocol, allowing us to obtain viable micro-grafts. In particular, we reported that this innovative protocol is able to create bio-complexes composed by autologous micro-grafts and collagen sponges ready to be applied on skin lesions. The clinical application of autologous bio-complexes on a leg lesion was also reported, showing an improvement of both re-epitalization process and softness of the lesion. Additionally, our in vitro model showed that cell viability after mechanical disaggregation with this system is maintained over time for up to seven (7) days of culture. We also observed, by flow cytometry analysis, that the pool of cells obtained from disaggregation is composed of several cell types, including mesenchymal stem cells, that exert a key role in the processes of tissue regeneration and repair, for their high regenerative potential. Finally, we demonstrated in vitro that this procedure maintains the sterility of micro-grafts when cultured in Agar dishes. In summary, we conclude that this new regenerative approach can be a promising tool for clinicians to obtain in one step viable, sterile and ready to use micro-grafts that can be applied alone or in combination with most common biological scaffolds.

The protocol describes a new method to disaggregate human tissues and to create autologous micro-grafts that, combined with collagen sponges, give rise to human bio-complexes ready to use in the treatment of skin lesions. Further, this system preserves cell viability of micro-grafts at different times after mechanical disaggregation.

Several new methods have been developed in the field of biotechnology to obtain autologous cellular suspensions during surgery, in order to provide one ...

Tissue-Engineered Graft for Circumferential Esophageal Reconstruction in Rats

The use of biocompatible materials for circumferential esophageal reconstruction is a technically challenging task in rats and requires an optimal implant technique with nutritional support. Recently, there have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in early epithelization in the special environment of peristalsis. Here, we developed an artificial esophagus that can improve the regeneration of the esophageal mucosa and muscle layers through a two-layered tubular scaffold, a mesenchymal stem cell-based bioreactor system, and a bypass feeding technique with modified gastrostomy. The scaffold is made of polyurethane (PU) nanofibers in a cylindrical shape with a three-dimensional (3D) printed polycaprolactone strand wrapped around the outer wall. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. We improved the graft survival rate by applying surgical anastomosis and covering the implanted prosthesis with a thyroid gland flap, followed by temporary nonoral gastrostomy feeding. These grafts were able to recapitulate the findings of initial epithelialization and muscle regeneration around the implanted sites, as demonstrated by histological analysis. In addition, increased elastin fibers and neovascularization were observed in the periphery of the graft. Therefore, this model presents a potential new technique for circumferential esophageal reconstruction.

Esophageal reconstruction is a challenging procedure, and development of a tissue-engineered esophagus that enables regeneration of esophageal mucosa and muscle and that can be implanted as an artificial graft is necessary. Here, we present our protocol to generate an artificial esophagus, including scaffold manufacturing, bioreactor cultivation, and various surgical techniques.

The use of biocompatible materials for circumferential esophageal reconstruction is a technically challenging task in rats and requires an optimal implant ...

Assessment of Acute Wound Healing using the Dorsal Subcutaneous Polyvinyl Alcohol Sponge Implantation and Excisional Tail Skin Wound Models.

Wound healing is a complex process that requires the orderly progression of inflammation, granulation tissue formation, fibrosis, and resolution. Murine models provide valuable mechanistic insight into these processes; however, no single model fully addresses all aspects of the wound healing response. Instead, it is ideal to use multiple models to address the different aspects of wound healing. Here, two different methods that address diverse aspects of the wound healing response are described. In the first model, polyvinyl alcohol sponges are subcutaneously implanted along the mouse dorsum. Following sponge retrieval, cells can be isolated by mechanical disruption, and fluids can be extracted by centrifugation, thus allowing for a detailed characterization of cellular and cytokine responses in the acute wound environment. A limitation of this model is the inability to assess the rate of wound closure. For this, a tail skin excision model is utilized. In this model, a 10 mm x 3 mm rectangular piece of tail skin is excised along the dorsal surface, near the base of the tail. This model can be easily photographed for planimetric analysis to determine healing rates and can be excised for histological analysis. Both described methods can be utilized in genetically altered mouse strains, or in conjunction with models of comorbid conditions, such as diabetes, aging, or secondary infection, in order to elucidate wound healing mechanisms.

Here, two murine wound healing models are described, one designed to assess cellular and cytokine wound healing responses and the other to quantify the rate of wound closure. These methods can be used with complex disease models such as diabetes to determine mechanisms of various aspects of poor wound healing.

Wound healing is a complex process that requires the orderly progression of inflammation, granulation tissue formation, fibrosis, and resolution. Murine ...

Immunology and Infection

Accessing Collagen Scaffold for Single-Stage Urinary Diversion Surgery in Pigs

Surgical Model for Single-Staged Tissue-Engineered Urothelial Tubes in Minipigs

Reconstructive surgeries are often challenged by a lack of grafting tissue. In the treatment of urogenital malformations, the conventional solution has been harvesting gastrointestinal tissue for non-orthotopic reconstruction due to its abundance to reestablish normal function in the patient. The clinical outcomes after rearranging native tissues within the body are often associated with significant morbidity; thus, tissue engineering holds specific potential within this field of surgery. Despite substantial advances, tissue-engineered scaffolds have not yet been established as a valid surgical treatment alternative, mainly due to the costly and complex requirements of materials, production, and implantation. In this protocol, we present a simple and accessible collagen-based tubular scaffold embedded with autologous organ-specific tissue particles, designed as a conduit for urinary diversion. The scaffold is constructed during the primary surgical procedure, comprises commonly available surgical materials, and requires conventional surgical skills. Secondly, the protocol describes an animal model designed to evaluate the short-term in vivo outcomes post-implantation, with the possibility of additional variations to the procedure. This publication aims to demonstrate the procedure step-by-step, with special attention to the use of autologous tissue and a tubular form.

Tissue-engineered implants for reconstructive surgery rarely progress beyond preclinical trials due to laborious ex vivo culturing, which includes complex and expensive scaffold components. Here, we present a single-staged procedure designed for urinary diversion with an accessible collagen-based tubular scaffold containing autologous micrografts.

Reconstructive surgeries are often challenged by a lack of grafting tissue. In the treatment of urogenital malformations, the conventional solution has ...

Digital Planimetry for Assessing Wound Closure Kinetics in a Mouse Model

Chronic wounds, due to their high prevalence, are a serious global health concern. Effective therapeutic strategies can significantly accelerate healing, thereby reducing the risk of complications and alleviating the economic burden on healthcare systems. Although numerous experimental studies have investigated wound healing, most rely on qualitative observations or quantitative direct measurements. The objective of this study was to standardize an indirect wound measurement method using digital planimetry, incorporating digital scaling and segmentation. This approach addresses the lack of detailed, step-by-step methodologies for accurate wound assessment. A photodocumentation booth was designed and constructed, and computer-assisted digital planimetry tools were employed to minimize variability in measurements of the wound area, perimeter, and the distance from the wound center to its edges. A circular traumatic wound (5 mm in diameter) was created on the dorsal midline at the shoulder blade level of male CD1 mice (n = 4, 10 weeks old, 30-35 g). Wound evolution was photodocumented for 14 days using the custom-designed photo booth, which controlled lighting conditions, focal distance, and subject positioning. Scaling and wound measurements were performed using segmentation in ImageJ software, and statistical analysis was conducted using statistical analysis software. The kinetics of wound closure showed a slight increase in wound size and perimeter between day 0 and day 2, followed by a gradual decrease until complete closure by day 14. The photodocumentation booth and computer-assisted digital planimetry enabled quantitative measurements with minimal variability. In conclusion, these tools provide a reliable and reproducible method for evaluating wound closure kinetics in pre-clinical models.

Wounds represent a global health challenge. This study developed a standardized photo booth utilizing digital planimetry to minimize wound measurement variability. Monitoring wounds in mice over 14 days revealed an initial increase in wound area and perimeter, followed by gradual closure. This methodology may aid in evaluating wound closure kinetics in pre-clinical models.

Chronic wounds, due to their high prevalence, are a serious global health concern. Effective therapeutic strategies can significantly accelerate healing, ...

A Murine Model of a Burn Wound Reconstructed with an Allogeneic Skin Graft

Trivial superficial wounds heal without complications by primary intention. Deep wounds, such as full thickness burns, heal by secondary intention and require surgical debridement and skin grafting. Successful integration of the donor graft into a recipient wound bed depends on timely recruitment of immune cells, robust angiogenic response and new extracellular matrix formation. The development of novel therapeutic agents, which target some key processes involved in wound healing, are hindered by the lack of reliable preclinical models with optimized objective assessment of wound closure. Here, we describe an inexpensive and reproducible model of experimental full thickness burn wound reconstructed with an allogeneic skin graft. The wound is induced on the dorsum surface of anaesthetized inbred wild type mice from the BALB/C and SKH1-Hrhr backgrounds. The burn is produced using a brass template measuring 10 mm in diameter, which is preheated to 80 &#176;C and delivered at a constant pressure for 20 s. Burn eschar is excised 24 hours after the injury and replaced with a full thickness graft harvested from the tail of a genetically similar donor mouse. No specialized equipment is required for the procedure and surgical techniques are straightforward to follow. The method may be effortlessly implemented and reproduced in most research settings. Certain limitations are associated with the model. Due to technical difficulties, the harvest of thinner split thickness skin grafts is not possible. The surgical method we describe here allows for the reconstruction of burn wounds using full thickness skin grafts. It may be used to carry out preclinical therapeutic testing.

The aim of this study was to develop a murine model of burn wound healing. A thermal burn was induced on the dorsal skin of mice using a preheated brass template. Burned tissue was debrided and overlaid with a skin graft harvested from the tail of a genetically similar donor mouse.

Trivial superficial wounds heal without complications by primary intention. Deep wounds, such as full thickness burns, heal by secondary intention and ...

A Case Series of Successful Abdominal Closure Utilizing a Novel Technique Combining a Mechanical Closure System with a Biologic Xenograft that Accelerates Wound Healing

Summary

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Digital Planimetry for Assessing Wound Closure Kinetics in a Mouse Model

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