Improved Preservation of Rat Small Intestine Transplantation Graft by Introduction of Mesenchymal Stem Cell-Secreted Fractions.

Segmental grafts from living donors have advantages over grafts from deceased donors when used for small intestine transplantation. However, storage time for small intestine grafts can be extremely short and optimal graft preservation conditions for short-term storage remain undetermined. Secreted factors from mesenchymal stem cells (MSCs) that allow direct activation of preserved small intestine grafts. Freshly excised Luc-Tg LEW rat tissues were incubated in preservation solutions containing MSC-conditioned medium (MSC-CM). Preserved Luc-Tg rat-derived grafts were then transplanted to wild-type recipients, after which survival, injury score, and tight junction protein expression were examined. Luminance for each graft was determined using in vivo imaging. The findings indicated that 30-100 and 3-10 kDa fractions of MSC-CM have superior activating effects for small intestine preservation. Expression of the tight-junction proteins claudin-3, and zonula occludens-1 preserved for 24 h in University of Wisconsin (UW) solution containing MSC-CM with 50-100 kDa, as shown by immunostaining, also indicated effectiveness. Reflecting the improved graft preservation, MSC-CM preloading of grafts increased survival rate from 0% to 87%. This is the first report of successful transplantation of small intestine grafts preserved for more than 24 h using a rodent model to evaluate graft preservation conditions that mimic clinical conditions.

Therapeutic application of decellularized porcine small intestinal submucosa scaffold in conjunctiva reconstruction.

The objective of this study was to investigate the biological feasibility and surgical applicability of decellularized porcine small intestinal submucosa (DSIS) in conjunctiva reconstruction. A total of 52 Balb/c mice were included in the study. We obtained the DSIS by decellularization, evaluated the physical and biological properties of DSIS in vitro, and further evaluated the effect of surgical transplantation of DSIS scaffold in vivo. The histopathology and ultrastructural analysis results showed that the scaffold retained the integrity of the fibrous morphology while removing cells. Biomechanical analysis showed that the elongation at break of the DSIS (239.00 ± 12.51%) were better than that of natural mouse conjunctiva (170.70 ± 9.41%, P < 0.05). Moreover, in vivo experiments confirmed the excellent biocompatibility of the decellularized scaffolds. In the DSIS group, partial epithelialization occurred at day-3 after operation, and the conjunctival injury healed at day-7, which was significantly faster than that in human amniotic membrane (AM) and sham surgery (SHAM) group (P < 0.05). The number and distribution of goblet cells of transplanted DSIS were significantly better than those of the AM and SHAM groups. Consequently, the DSIS scaffold shows excellent biological characteristics and surgical applicability in the mouse conjunctival defect model, and DSIS is expected to be an alternative scaffold for conjunctival reconstruction.

Immune reactions following intestinal transplantation: Mechanisms and prevention.

For patients with intestinal failure, small bowel transplantation remains one of the most effective treatments despite continuous advancements in parenteral nutrition techniques. Long-term use of parenteral nutrition can result in serious complications that lead to metabolic dysfunction and organ failure. However, the small intestine is a highly immunogenic organ with a large amount of mucosa-associated lymphoid tissue and histocompatibility antigens; therefore, the small intestine is highly susceptible to severe immune rejection. This article discusses the mechanisms underlying immune rejection after small bowel transplantation and presents various options for prevention and treatment. Our findings offer new insights into the development of small bowel transplantation.

An overview of the current management of short-bowel syndrome in pediatric patients.

Short-bowel syndrome (SBS) is defined as a state of malabsorption after resection or loss of a major portion of the bowel due to congenital or acquired factors. This article presents an overview on the recent management of pediatric SBS. The pediatric SBS population is very heterogeneous. The incidence of SBS is estimated to be 24.5 per 100,000 live births. The nutritional, medical, and surgical therapies available require a comprehensive evaluation. Thus, multidisciplinary intestinal rehabilitation programs (IRPs) are necessary for the management of these complex patients. The key points of focus in IRP management are hepato-protective strategies to minimize intestinal failure-associated liver disease; the aggressive prevention of catheter-related bloodstream infections; strategic nutritional supply to optimize the absorption of enteral calories; and the management and prevention of small bowel bacterial overgrowth, nephrocalcinosis, and metabolic bone disease. As the survival rate of children with SBS currently exceeds 90%, the application of small bowel transplantation has been evolving. The introduction of innovative treatments, such as combined therapy of intestinotrophic hormones, including glucagon-like peptide-2, may lead to further improvements in patients' quality of life.

A novel technique for large lateral enterocutaneous fistula management after intestinal transplantation.

BACKGROUND: Enterocutaneous fistula (ECF) is a serious and complex problem when affecting children, being responsible for a high morbidity burden, with an estimated mortality rate of 10 to 20%. There are many therapeutic options, including surgery and a wide variety of nonoperative strategies. Prognosis of ECF closure depends on the output and also on the patency of distal bowel. Spontaneous closure without operative intervention occurs in approximately 50% of patients with lateral ECF and distal bowel transit, but this drastically decreases in high output fistulas. High-volume fistula output and consequent skin damage are a great challenge for the health-care team. METHODS: We describe a postoperative complication that required a new nonoperative technique for the transient management of a lateral high-output ECF, involving the insertion of an occlusive device in order to redirect intestinal content to the distal bowel, reducing the fistula output. RESULTS AND CONCLUSIONS: The main benefit of this nonoperative technique is the ability to occlude a high-output fistula, allowing the distal flow to be restored and reducing abdominal wall damage, as a bridge to definitive surgical closure.

Paraneoplastic pemphigus associated with post-transplant lymphoproliferative disorder after small bowel transplantation.

BACKGROUND: PNP is a malignancy-associated autoimmune mucocutaneous syndrome due to autoantibodies against plakins, desmogleins, and other components of the epidermis and basement membrane of epithelial tissues. PNP-causing malignancies comprise mainly lymphoproliferative and hematologic neoplasms. PNP is extremely rare, especially in children. METHODS: Here, we present the first case of a child who developed PNP on a PTLD after small bowel transplantation because of a severe genetic protein-losing enteropathy. RESULTS: The patient in this case report had a severe stomatitis, striate palmoplantar keratoderma, and lichenoid skin lesions. In addition, she had marked esophageal involvement. She had lung pathology due to recurrent pulmonary infections and ventilator injury. Although we found no evidence of BO, she died from severe pneumonia and respiratory failure at the age of 12 years. CONCLUSION: It is exceptional that, despite effective treatment of the PTLD, the girl survived 5 years after her diagnosis of PNP. We hypothesize that the girl survived relatively long after the PNP diagnosis due to strong T-cell suppressive treatments for her small bowel transplantation.

Ex vivo normothermic perfusion of isolated segmental porcine bowel: a novel functional model of the small intestine.

BACKGROUND: There is an unmet need for suitable ex vivo large animal models in experimental gastroenterology and intestinal transplantation. This study details a reliable and effective technique for ex vivo normothermic perfusion (EVNP) of segmental porcine small intestine. METHODS: Segments of small intestine, 1.5-3.0 m in length, were retrieved from terminally anaesthetized pigs. After a period of cold ischaemia, EVNP was performed for 2 h at 37°C with a mean pressure of 80 mmHg using oxygenated autologous blood diluted with Ringer's solution. The duration of EVNP was extended to 4 h for a second set of experiments in which two segments of proximal to mid-ileum (1.5-3.0 m) were retrieved from each animal and reperfused with whole blood (control) or leucocyte-depleted blood to examine the impact of leucocyte depletion on reperfusion injury. RESULTS: After a mean cold ischaemia time of 5 h and 20 min, EVNP was performed in an initial group of four pigs. In the second set of experiments, five pigs were used in each group. In all experiments bowel segments were well perfused and exhibited peristalsis during EVNP. Venous glucose levels significantly increased following luminal glucose stimulation (mean(s.e.m.) basal level 1.8(0.6) mmol/l versus peak 15.5(5.8) mmol/l; P < 0.001) and glucagon-like peptide 1 (GLP-1) levels increased in all experiments, demonstrating intact absorptive and secretory intestinal functions. There were no significant differences between control and leucocyte-depleted animals regarding blood flow, venous glucose, GLP-1 levels or histopathology at the end of 4 h of EVNP. CONCLUSIONS: This novel model is suitable for the investigation of gastrointestinal physiology, pathology and ischaemia reperfusion injury, along with evaluation of potential therapeutic interventions.

Post-stapedotomy reparative granuloma following use of acellular porcine small intestinal submucosa.

PURPOSE: There have been multiple proposed etiologies of reparative granuloma following stapes surgery. In this report, we present the first case of post-stapedectomy reparative granuloma following the use of Biodesign (Cook Medical, Bloomington, IN) otologic graft material, an acellular matrix derived from porcine small intestinal submucosa, and review the literature of post-stapes surgery reparative granuloma. PATIENT: 50-year-old woman who developed a reparative granuloma following stapedotomy with acellular porcine intestinal submucosa presenting with profound hearing loss and vertigo. INTERVENTION: Middle ear exploration with excision of granuloma and revision stapedotomy. MAIN OUTCOME MEASURES: Audiologic outcomes as measured by pure-tone air and bone conduction thresholds and word recognition scores. Improvement in vertigo. MAIN FINDINGS: Surgical excision of the reparative granuloma with revision stapedotomy resolved vertigo. Hearing has improved progressively postoperatively. CONCLUSIONS: We report the first case of post-stapedotomy reparative granuloma following the use of acellular porcine intestinal submucosa. Although exact etiology cannot be determined from a single case report, this illustrates the need for careful use of novel foreign graft material. This case additionally confirms that removal of granuloma and inciting materials can salvage serviceable hearing.

Post-transplant hepatic fibrosis in pediatric liver-small bowel transplant recipients: A single-center, retrospective, observational study.

BACKGROUND: Little is known about the prevalence of hepatic graft fibrosis in combined LSBT children. We aimed to determine the prevalence of and identify potential predictors for hepatic graft fibrosis in LSBT children and to compare them with those in LT children. METHODS: We retrospectively included children younger than 19 years who had received a primary LT/LSBT between 2000 and 2018 and had a liver biopsy performed at least 6 months post-transplant. A Cox proportional hazards regression model was used to determine predictors associated with significant hepatic graft fibrosis (≥F2) in LSBT vs LT children. RESULTS: Ninety-six children (47 LSBT, 54 females) were included. The median post-transplant follow-up (years) was 12.8 in LT vs 10.5 in LSBT patients (P = .06). Hepatic graft fibrosis was found in 81.6% of LT vs 70.2% of LSBT children (P = .19), after a median time of 2.5 years and 2.6 years, respectively. On multivariate analyses, having post-transplant biliary complications was found to be associated with significant graft fibrosis in LT children, whereas AST/ALT ratio was found to predict significant hepatic graft fibrosis in LSBT children. The use of parenteral nutrition after transplant was not associated with significant hepatic graft fibrosis. CONCLUSIONS: The prevalence of hepatic graft fibrosis in LSBT children did not significantly differ from that in LT children, but the predictors may differ. Future studies should investigate the role of post-transplant autoimmune antibodies and donor-specific antibodies in the development and progression of hepatic graft fibrosis in LSBT children.

Surveillance of Rejection After Intestinal Transplantation Using an Image Enhanced Endoscopy "VENCH" Scoring System.

BACKGROUND: Graft rejection after intestinal transplantation remains challenging. We aimed to use endoscopy for rejection prediction. MATERIALS AND METHODS: Patients ≥7 years old who underwent intestinal transplantation between November 2016 and September 2019 were prospectively enrolled. Magnifying endoscopy under narrow-band imaging was performed through ileostomy. Endoscopic findings were reported as five components (each graded from 0-2): "V" (villi appearance), "E" (erythema), "N" (capillary network), "C" (crypt widening), and "H" (heterogeneity). The correlation between histological severity and endoscopic score was analyzed. RESULTS: Ninety-nine endoscopic biopsies from three female and one male patient were analyzed. The mean ± SD age was of 41.25±13.77 (range 29-58) years. Three short bowel syndrome patients after multiple intestinal resections and one with chronic intestinal pseudo-obstruction were indicated for intestinal transplantation. Sensitivity, specificity, and accuracy of V, E, N, C, and H scores for predicting rejection were 97.4%, 45.9%, 65.7%; 94.7%, 70.5%, 79.8%; 97.4%, 52.5%, 69.7%; 94.7%, 54.1%, 69.7%; and 97.4%, 62.3%, 75.8%, respectively. Pearson's correlation coefficients between total and individual V, E, N, C, H scores and histological rejection were 0.79, 0.64, 0.70, 0.71, 0.73, and 0.66, respectively (P < .001). To predict mild and moderate/severe rejection, total scores more than 4 and 6 had the sensitivity/specificity of 87.50%/57.38% and 96.67%/85.25%, respectively (area under the ROC 0.791 and 0.987). CONCLUSION: Endoscopic VENCH scoring is promising for predicting rejection after IT. More studies are warranted to validate such results. (ClinicalTrials.gov number, NCT03616548.).

De novo hepatocellular carcinoma 18 years after liver and small bowel transplantation in a one-year-old pediatric patient.

De novo HCC following transplantation in a child is a rare occurrence. Even within the adult liver transplantation population, there are a limited number of published cases. In this report, we present a case of de novo HCC found in a child, post-multivisceral transplantation. A 19-year-old boy, at the age of one, received liver and small bowel transplantation due to short gut syndrome secondary to midgut volvulus and total parenteral nutrition-associated liver disease. Eighteen years later, he was found to have a large mass involving the right hepatic dome consistent with HCC. To the best of our knowledge, this is the second reported case after gut transplantation and the third case post-liver transplantation in the pediatric population.

30-Day Outcomes Following Esophageal Replacement in Children: A National Surgical Quality Improvement Project Pediatric Analysis.

INTRODUCTION: The optimal method of esophageal replacement remains controversial. The aim of this study was to evaluate 30-d outcomes of children in the National Surgical Quality Improvement Project Pediatric (NSQIP-P) database who underwent esophageal replacement from 2012 to 2018. METHODS: Demographics, comorbidities, and procedural technique was identified in NSQIP-P and reviewed. Thirty-day outcomes were assessed and stratified by gastric pull-up or tube interposition versus small bowel or colonic interposition. Categorical and continuous variables were assessed by Pearson's chi-square, Fisher's exact, and Wilcoxon rank-sum tests, respectively. Multivariate logistic regression was performed to estimate the effects of procedure technique and clinical risk factors on patient outcomes. RESULTS: Of the 99 cases of esophageal replacement included, 52 (52.5%) utilized a gastric conduit, whereas 47 (47.5%) involved small bowel/colonic esophageal interposition. Overall risk of complications was 52.5%, the most common of which were perioperative transfusion (30.3%), surgical site infection (11.1%), and sepsis (9.1%). Risk of unplanned reoperation was 17.2%, and risk of mortality was 3.0%. Risk for complications, reoperation, and readmission did not differ significantly between those who underwent gastric esophageal replacement and those who underwent small bowel or colonic interposition. Median operative time was shorter in the gastric esophageal replacement group (5.2 versus 8.1 h, P = 0.009). CONCLUSIONS: Among children in NSQIP-P who underwent esophageal replacement from 2012 to 2018, the risk of 30-d complications, unplanned reoperation, and mortality was relatively frequent and was similar across operative techniques. Opportunities exist to improve preoperative optimization, utilization of blood transfusion services, and infectious complications in the perioperative period irrespective of operative technique. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

[Stage-by-stage treatment of vesicovaginal fistula followed by orthotopic plastic surgery of the bladder and vagina with a small intestine]. / Etapnoe lechenie puzyrno-vlagalishchnogo svishcha s posleduyushchei ortotopicheskoi plastikoi mochevogo puzyrya i vlagalishcha tonkoi kishkoi.

High incidence of iatrogenic lesions of genitourinary system (during gynecological and oncogynecological operations) followed by urogenital fistulae and great percentage of recurrences after reconstructive surgery justify the need to improve surgical reconstruction of genitourinary organs and urine discharge in these patients. Stage-by-stage surgical treatment of a patient with extensive vesicovaginal fistula is reported in the article. A defect was associated with loss of 2/3 of the volume of tissues of adjacent organs. Multiple operations in various clinics were failed to eliminate the fistula and resulted decrease of bladder capacity up to microcystis.

[Quality of life after reconstructive procedures for esophageal strictures]. / Otsenka kachestva zhizni bol'nykh posle rekonstruktivnykh operatsii pri rubtsovykh suzheniyakh pishchevoda.

OBJECTIVE: To study the long-term results of reconstructive procedures for esophageal strictures and evaluate quality life after each type of esophageal repair using own criteria. MATERIAL AND METHODS: The study was conducted among patients who underwent esophageal repair with gastric transplant (172), colonic transplant (25), intestinal transplant (14) and repair of short cervical strictures (7). The age of patients ranged from 5 to 60 years. All patients underwent X-ray and endoscopic examination. Survey also included external respiration function and cardiac function, digestive function, measurement of height and weight, analysis of social aspects (work, study), female genital function. Five-score scale for quality of life assessment was developed. RESULTS: Long-term results were studied in 218 patients for the period from 3 months to 31 years (2002-2017). Excellent and good results were obtained in 180 patients. The best results were obtained after repair of short cervical strictures (4.42 scores), good results - after esophageal repair with gastric (4.14 scores) and intestinal (4.07 scores) transplants. Colonic repair was followed by satisfactory outcome (3.16 scores). CONCLUSION: Gastric and small bowel grafts are preferred for total esophageal repair due to better quality of life in long-term postoperative period.

17ß-Estradiol as a New Therapy to Preserve Microcirculatory Perfusion in Small Bowel Donors.

BACKGROUND: Intestine graft viability compromises retrieval in most brain-dead donors. Small bowel transplantation is a complex procedure with worse outcomes than transplantation of other abdominal organs. The hormone 17ß-estradiol (E2) has shown vascular protective effects in lung tissue of brain death (BD) male rats. Thus, estradiol might be a treatment option to improve the quality of intestinal grafts. METHODS: Male Wistar rats were divided into 3 groups (n = 10/group): rats that were trepanned only (sham-operated), rats subjected to rapid-onset BD, and brain-dead rats treated with E2 (280 µg/kg, intravenous) (BD-E2). Experiments performed for 180 minutes thereafter are included: (a) laser-Doppler flowmetry and intravital microscopy to evaluate mesenteric perfusion; (b) histopathological analysis; (c) real-time polymerase chain reaction of endothelial nitric oxide synthase (eNOS) and endothelin-1; (d) immunohistochemistry of eNOS, endothelin-1, P-selectin, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 expression; and (e) ELISA for cytokines and chemokines measurement. RESULTS: 17ß-Estradiol improved microcirculatory perfusion and reduced intestinal edema and hemorrhage after BD. The proportions of perfused small vessels were (mean ± scanning electron microscope) BD rats (40% ± 6%), sham-operated rats (75% ± 8%), and BD-E2 rats (67% ± 5%) (P = 0.011). 17ß-Estradiol treatment was associated with 2-fold increase in eNOS protein (P < 0.0001) and gene (P = 0.0009) expression, with no differences in endothelin-1 expression. BD-E2 rats exhibited a reduction in vascular cell adhesion molecule 1 expression and reduced cytokine-induced neutrophil chemoattractant 1 and interleukina-10 serum levels. CONCLUSIONS: 17ß-Estradiol was effective in improving mesenteric perfusion and reducing intestinal edema and hemorrhage associated with BD. The suggestion is that E2 might be considered a therapy to mitigate, at least in part, the deleterious effects of BD in small bowel donors.

Single port laparoscopy combined with vaginal cervicovaginal reconstruction in a patient with congenital atresia of the cervix.

OBJECTIVE: To introduce an innovation that combines single port laparoscopic and Wharton-Sheares-George cervicovaginal reconstruction using a small intestinal submucosa (SIS) graft in a patient with congenital cervical atresia, absence of vagina, and incomplete uterine septum (U2aC4V4). DESIGN: Video article introducing a new surgical technique. SETTING: University hospital. PATIENT(S): A 15-year-old patient with congenital cervical atresia, absence of vagina, and incomplete uterine septum had primary amenorrhea and cyclic lower abdominal pain. The magnetic resonance imaging did not show hematometra and the endometrium was 6 mm when she had lower abdominal pain. INTERVENTION(S): A neovagina (depth, 7 cm; width, 2.5 cm) was created using the Wharton-Sheares-George neovaginoplasty. By single laparoscopy, the bladder was separated from the anterior surface of the uterus. With the mold in the neovagina created by the assistant, the apex of neovagina was opened. Then the lower uterine segment was exposed and incised. A T-shaped intrauterine device was connected to an 8-cm-long catheter scissored from a 14-F Foley catheter and was inserted into the uterus to prevent cervical or vaginal stenosis. The upper end of the graft was applied onto the lower uterine segment with delayed absorbable sutures. The lower end was sutured to the high vaginal or vestibular mucosa. MAIN OUTCOME MEASURE(S): The feasibility and effect of combination single port laparoscopic with vaginal cervicovaginal reconstruction in the congenital atresia of cervix. RESULT(S): The operation was successful. The operating time was 90 minutes. Hospitalization was 3 days. There were no intraoperative and postoperative complications. The patient had resumption of menses at three cycles postoperatively, and she had no dysmenorrhea. No cervical or vaginal stenosis occurred because of the Foley catheter. CONCLUSION(S): Single port laparoscopic combined with vaginal cervicovaginal reconstruction provided a minimally invasive, safe, and effective surgical option for the young patient with congenital atresia of cervix. It was successful and without complications or cervical or vaginal stenosis.

Gastrointestinal Tract Reconstruction in Adults with Ultra-Short Bowel Syndrome: Surgical and Nutritional Outcomes.

BACKGROUND: Historically, adults with ultra short bowel syndrome (USBS) have been considered candidates for lifetime parenteral nutrition (PN) or are referred for visceral transplantation. We examined the surgical and nutritional outcomes of adult patients with USBS managed at a single intestinal rehabilitation center. METHODS: We retrospectively reviewed data on 588 adult patients referred to our center between January 2013 and December 2018. USBS was defined as residual small bowel (SB) length ≤ 50 cm. RESULTS: Forty-five patients (7.6%) with a mean age of 46.7 years (range 17-78) were identified. Indications for enterectomy included mesenteric ischemia (n=17) and internal hernias (n=6), followed by large intraabdominal fibroids, trauma, and allograft enterectomies, with five cases each. Median SB length was 18.0 cm; 20 patients (44.4%) had their entire SB resected. Thirteen patients had an intact colon, of which nine had preservation of the ileocecal valve. Patients who underwent autologous reconstruction of their gastrointestinal (GI) tract required a lower total PN volume (29.0 ± 7.6 vs. 40.8 ± 13.2 ml/Kg/day, p=0.002) and presented better short- and long- term survival (p=0.005). Patients with no gut had higher mortality (p=0.036). Hormonal therapy with the glucagon-like peptide-2 analog teduglutide was used in nine patients (20%) five of whom were weaned off TPN. Excluding patients with no gut (n=20), discontinuation of total PN rate for patients with an end ostomy or tube decompression (n= 6), jejunocolostomy (n= 10), and jejunoileostomy (n=9) were 0%, 40%, and 77.7%, respectively. Eleven patients (44%) with some residual small intestine achieved nutritional autonomy in an average of 20 months after GI reconstruction. Fifteen patients were listed for transplantation (33.3%). Seven patients underwent isolated SB transplantation and achieved nutritional autonomy in an average of three months after transplantation. One-year patient and graft survival were 100%. After a 37-month median follow-up period, 36 of 42 patients followed by our center were still alive (85.7%). CONCLUSION: Nutritional autonomy can be achieved in a significant number of patients with USBS in specialized centers with surgical and/or hormonal therapy. The presence of an intact colon and ileocecal valve can significantly increase the adaptation rate. Moreover, restoration of GI tract continuity has a positive impact on medical management and survival.

Using Bioengineered Fluorescence for Selective In Vivo and Ex Vivo Tracking of Intestinal Organoids Derived from Human Pluripotent Stem Cells.

For current and future applications of human intestinal organoids (hIOs) to various aspects of in vivo research and their potential clinical use, an efficient noninvasive system is needed to directly visualize the stage of intestinal differentiation and graft-host interactions and for further safety monitoring and efficacy. Here, we describe a detailed method for monitoring and histologically identifying implanted hIO-expressing eGFP and mCherry fluorescence under the kidney capsule of immunodeficient mice with fluorescence imaging (FLI). We then describe the orthotropic transplantation method of hIOs and methods to confirm successful engraftment in the small intestines of immunodeficient mice. These methods provide an approach for tracking the location of intestinal cells in hIOs in vivo and ex vivo using a fluorescent reporter system from the beginning of engraftment to various subsequent experiments.

[Outcomes of implanting porcine small intestinal submucosa mesh in rabbit vesicovaginal space].

Objective: To assess surgical outcomes of implanted porcine small intestinal submucosa (SIS) mesh in the rabbit vesicovaginal space (VVS) and explore its application value in pelvic floor reconstruction surgery. Methods: Sixteen male rabbits were randomly divided into four groups, and each group had four rabbits. All groups of rabbits were implanted with SIS mesh in the vesicovaginal space. They were humanely killed after a postoperative period of 7, 30, 90 and 180 days by group. The grafted area was removed with the surrounding bladder and vaginal tissues. The specimens were embedded in paraffin and then stained with HE and Masson's trichrome stains for visual observations, cells counts, and assessment of tissues and collagen fibers. Results: (1) After HE staining, a large number of inflammatory response cells mainly eosinophils and lymphocytes infiltrated around the SIS mesh in 7 days group, and neovascularization was observed, the infiltration area of inflammatory response cells further increased in 30 days group, the infiltration area of inflammatory response cells significantly reduced in 90 days group, while the inflammatory response basically subsided in 180 days group. (2) After Masson's trichromestaining, the collagen structure of SIS mesh in 7 days group was clear and intact. While, the collagen structure of SIS mesh was partially degraded in 30 days group, the SIS meshes of 4 rabbits were completely degraded, but the collagen fragments of SIS remained in 90 days group. In 180 days group, the SIS mesh of all rabbits was degraded, and one of them had the formation of new collagen fibers. Conclusions: SIS mesh implanted into the VVS of rabbits can lead to a transient non infective inflammatory reaction, which could be completely degraded and a small amount of new collagen fibers could be produced after 180 days of implantation. Which shown that SIS mesh should be used cautiously in pelvic floor reconstruction surgery.