A first-in-human clinical study of laparoscopic autologous myoblast sheet transplantation to prevent delayed perforation after duodenal endoscopic mucosal dissection.

BACKGROUND: The detection rate of superficial non-ampullary duodenal epithelial tumors (SNADETs) has recently been increasing. Large tumors may contain malignant lesions and early therapeutic intervention is recommended. Endoscopic mucosal dissection (ESD) is considered a feasible treatment modality, however, the anatomical and physiological characteristics of the duodenum create a risk of postoperative perforation after ESD. METHODS: To explore whether myoblast sheet transplantation could prevent delayed perforation after ESD, a first-in-human (FIH) clinical trial of laparoscopic autologous myoblast sheet transplantation after duodenal ESD was launched. Autologous myoblast sheets fabricated from muscle tissue obtained seven weeks before ESD were transplanted laparoscopically onto the serous side of the ESD. The primary endpoints were the onset of peritonitis due to delayed perforation within three days after surgery and all adverse events during the follow-up period. RESULTS: Three patients with SNADETs ≥ 20 mm in size underwent transplantation of a myoblast sheet onto the serous side of the duodenum after ESD. In case 1, The patient's postoperative course was uneventful. Endoscopy and abdominal computed tomography revealed no signs of delayed perforation. Despite incomplete mucosal closure in case 2, and multiple micro perforations during ESD in case 3, cell sheet transplantation could prevent the postoperative massive perforation after ESD, and endoscopy on day 49 after transplantation revealed no stenosis. CONCLUSIONS: This clinical trial showed the safety, efficacy, and procedural operability of this novel regenerative medicine approach involving transplanting an autologous myoblast sheet laparoscopically onto the serosa after ESD in cases with a high risk of delayed perforation. This result indicates the potential application of cell sheet medicine in treating various abdominal organs and conditions with minimal invasiveness in the future. TRIAL REGISTRATION: jRCT, jRCT2073210094. Registered November 8 2021, https://jrct.niph.go.jp/latest-detail/jRCT2073210094 .

Outcomes of living donor liver transplant recipients receiving grafts with the graft-to-recipient weight ratio less than 0.6%: A matched pair analysis.

We sometimes experience living donor liver transplantation (LDLT) involving very small grafts with graft-to-recipient weight ratio (GRWR) < 0.6% when the actual graft size is smaller than predicted. The outcomes in this situation have not been fully investigated. The present study aimed to determine the graft outcomes of LDLT with GRWR < 0.6%. We retrospectively reviewed 280 cases of adult LDLT performed at our institution between January 2000 and March 2021. In our institution, the lower limit for graft volume/standard liver volume ratio was 30%. The patients were divided into 2 groups according to the cutoff value of 0.6% for actual GRWR. Graft survival and surgical outcomes, including small-for-size syndrome (SFSS), were compared between the groups using propensity score matching analysis. Risk factors associated with SFSS in recipients with GRWR < 0.6% were also evaluated. Fifty-nine patients received grafts with GRWR < 0.6%. After propensity score matching, similar graft survival rates were observed for GRWR < 0.6% (n = 53) and GRWR ≥ 0.6% (n = 53) ( p = 0.98). However, patients with GRWR < 0.6% had a significantly worse 3-month graft survival rate (86.8% vs. 98.1%, p = 0.03) and higher incidence of SFSS ( p < 0.001) than patients with GRWR ≥0.6%. On multivariate analysis, Model for End-Stage Liver Disease score and donor age were associated with SFSS in patients with GRWR < 0.6%. The same factors were also associated with graft survival. In conclusion, although similar overall graft survival rates were observed for LDLT with GRWR < 0.6% and GRWR ≥ 0.6%, GRWR < 0.6% was associated with an increased risk of SFSS. Appropriate donor and recipient selection is important for successful LDLT with very small grafts.

Feasibility of Organ Transportation by a Drone: An Experimental Study Using a Rat Model.

BACKGROUND: Recently, the successful delivery of organs for transplantation using drones was reported. We investigated the influence of transportation by drones on the quality of liver grafts using a rat model. METHODS: Livers of 12 rats (8 and 32 weeks old) were divided into 2 groups of six. Livers were split into 2 parts and allocated to the drone or control groups (both n = 12). The drone experiment was conducted between islands in Nagasaki Prefecture, Japan. The distance between the islands was 12 km. Livers of the drone group were transported by a multicopter at a speed of 30 km-40 km/h over 60 m above sea level. Transported liver quality was analyzed by histology, and biochemistry data were compared between groups. RESULTS: Cold ischemia time did not differ between groups (902 min and 909 min, respectively). There were no differences in macroscopic findings regarding coloration and damage between groups. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in preservation fluid were graft weight-corrected and compared, and no significant differences were found between groups: AST/g (4.61 vs 4.81 IU/L), ALT/g (2.78 vs 2.92 IU/L), and ALP/g (39.1 vs 37.0 IU/L). Immunochemical staining showed no significant difference between groups for terminal deoxynucleotidyl transferase dUTP nick and labeling staining (141 vs 113 cells), CD163 (818 vs 870 cells), and TNF-α (1.25 vs 1.41 scores). CONCLUSIONS: The simulation experiment of organ transport for transplantation by drones was successfully conducted. There were no differences in the quality of livers transported by drones or other means. Further studies including large-animal experiments could lead to future clinical applications.

Endoscopic mucosal ischemic index for predicting anastomotic complications after esophagectomy: a prospective cohort study.

BACKGROUND: Postoperative complications related to gastric conduit reconstruction are still common issues after McKeown esophagectomy. A novel endoscopic mucosal ischemic index is desired to predict anastomotic complications after McKeown esophagectomy. AIMS AND METHODS: The purpose of this study was to prospectively evaluate the safety and efficacy of endoscopic examinations of the anastomotic region in the acute period after esophagectomy. Endoscopic examinations were performed on postoperative days (PODs) 1 and 8. The severity of ischemia was prospectively validated according to the endoscopic mucosal ischemic index (EMII). RESULTS: A total of 58 patients were included after evaluating the safety and feasibility of the endoscopic examination on POD 1 in 10 patients. Anastomotic leakage occurred in 6 patients. Stricture occurred in 13 patients. A greater than 67% circumference and lesion length greater than 20 mm of anastomotic ischemic area (AIA) on POD 1 were associated with developing anastomotic leakage after esophagectomy (OR: 14.5; 95% CI: 1.8-306.5; P = 0.03, OR: 19.4; 95% CI: 1.7-536.8; P = 0.03). More than 67% circumferential ischemic mucosa and ischemic mucosal lengths greater than 20 mm of AIA on POD 1 were associated with developing anastomotic strictures after esophagectomy (OR: 6.4; 95% CI: 1.4-31.7; P = 0.02, OR: 5.9; 95% CI: 1.2-33.1; P = 0.03). Patients with either more than 67% circumferential ischemic mucosa or ischemic mucosal lengths greater than 20 mm of AIA on POD 1 were defined as EMII-positive patients. The sensitivity, specificity, and positive and negative predictive values of EMII positivity on POD 1 for leakage were 100%, 78.8%, 35.3%, and 100%, respectively. The sensitivity, specificity, and positive and negative predictive values of the EMII positivity on POD 1 for strictures were 69.2%, 82.2%, 52.9%, and 90.2%, respectively. CONCLUSIONS: The application of an endoscopic classification system to mucosal ischemia after McKeown esophagectomy is both appropriate and satisfactory in predicting anastomotic complications. TRIAL REGISTRATION: Clinical Trial.gov Registry, ID: NCT02937389, Registration date: Oct 17, 2015.

Transplantation of chemically-induced liver progenitor cells ameliorates hepatic fibrosis in mice with diet-induced nonalcoholic steatohepatitis.

Chemically-induced liver progenitors (CLiPs) have promising applications in liver regenerative medicine. We aimed to clarify the efficacy of CLiPs for ameliorating fibrosis in a diet-induced nonalcoholic steatohepatitis rat model, since nonalcoholic fatty liver disease is currently recognized as the most common form of chronic liver disease in developed countries. METHODS: Primary mature hepatocytes were isolated from 7-week-old male Wistar rats. To establish CLiPs, isolated hepatocytes were cultured in differentiation medium composed of Y-27632, A-83-01, and CHIR99021 (YAC medium). As an animal model that reproduces NASH pathophysiology, 6-week-old severe combined immunodeficient (SCID) mice were carefully selected and prepared and fed with choline-deficient, L-amino acid-defined, high-fat diet (HFD). After 12 weeks' HFD feeding, the mice were assigned to continue HFD with or without the administration of rat CLiPs (HFD + CLiPs and HFD-CLiPs, respectively). Rat CLiPs were administered from the spleen. Hepatic fibrosis was semi-quantitatively evaluated according to histology. Liver parenchyma and blood samples were collected for biochemical analyses. RESULTS: Rat CLiPs were positive for CK19 and EpCAM were successfully delivered to the liver. At 8 weeks after CLiPs transplantation, the HFD + CLiPs group showed significantly less positive staining than the HFD-CLiPs group. Alanine aminotransferase significantly improved in the HFD + CLiPs group, as demonstrated by Azan staining and αSMA immunostaining. RT qPCR showed that the liver expression of MMP2 and 9 tended to be higher in the HFD + CLiPs group. CONCLUSIONS: The anti-fibrotic effect of CLiPs was demonstrated in the immunodeficient NASH animal model and may have therapeutic applications in humans.

Rapid and chronological expression of angiogenetic genes is a major mechanism involved in cell sheet transplantation in a rat gastric ulcer model.

Introduction: Cell sheet technology has been applied in the treatment of patients with severe cardiac failure. Although the paracrine effect of cell sheets accelerating angiogenesis is thought to be the intrinsic mechanism for improvement of cardiac function, little is known about how a cell sheet would function in the abdomen. Methods: We used acetic acid-induced gastric ulcer rat model to elucidate the mechanisms of myoblast sheet transplantation in the abdomen. Myoblast sheet was implanted onto the serosal side of the gastric ulcer and the effect of sheet transplantation was analyzed. The maximal diameter of the ulcer and the changes in the gene expression of various growth factors in transplanted site was analyzed. The progenitor marker CD34 was also examined by immunohistochemistry. Results: Cell sheet transplantation accelerated the ulcer healing. qPCR showed that angiogenic growth factors were significantly upregulated around the ulcer in the transplantation group. In addition, at first, HIF-1a and SDF-1 continued to increase from 3 h after transplantation to 72 h, then VEGF increased significantly after 24 h with a slight delay. An immunohistochemical analysis showed a statistically significant increase in CD34 positivity in the tissue around the ulcer in the transplantation group. Conclusion: Myoblast sheet secreted various growth factors and cytokines immediately after transplantation onto the serosal side of artificial ulcer in the abdomen. Autonomous secretion, resulting in the time-dependent and well-orchestrated gene expression of various growth factors, plays a crucial role in the cell sheet function. Cell sheet transplantation is expected to be useful to support angiogenesis of the ischemic area in the abdominal cavity.

Highly feasible procedure for laparoscopic transplantation of cell sheets under pneumoperitoneum in porcine model.

INTRODUCTION: Cell sheet technology is one of the most successful methodologies in regenerative medicine. Various applications of cell sheets have been introduced in first-in-human studies in several clinical fields. When transplanting a cell sheet into internal organs, a relatively large incision is required for delivery due to difficulty handling the sheet. We developed a laparoscopic delivery procedure for safe and easy transplantation of cell sheets in a porcine model. METHODS: Pneumoperitoneum was established by inflation with CO2. First, to increase the strength during handling, fibrin was sprayed onto the surface of the cell sheet, and then a myoblast sheet was placed onto the newly developed carrier. The sheets were pinched with laparoscopic forceps to insert into the abdominal cavity through the laparoscopic port. Myoblast sheets were then applied to the surface of the liver, colon, small intestine, and stomach, and procedure times were measured. At three days post transplantation, a histopathological examination was performed to confirm engraftment of the sheet. The function and engraftment were also analyzed in a duodenal endoscopic submucosal dissection (ESD) model. RESULTS: The fibrin-processed myoblast sheet was able to be managed with conventional laparoscopic forceps without breaking. Despite the drastic change in air pressure by passing through the laparoscopic port, the sheets suffered no apparent damage. The transplantation procedure times did not markedly differ among transplant sites. A histopathological examination revealed thin-layered, desmin-positive cells at each transplant site. With transplantation following ESD, the engrafted myoblast sheets effectively prevented delayed perforation. CONCLUSIONS: Our procedure is simple, and the system involves a carrier made of medically fit silicon, commercially available fibrin glue and conventional laparoscopic forceps. Our procedure is a powerful tool for laparoscopical cell sheet transplantation.

[A Case of Unresectable Gastric Cancer with Paraaortic Lymph Node Metastasis Treated with Conversion Therapy].

We present a case of advanced gastric cancer with paraaortic lymph node metastasis successfully treated by conversion therapy. The patient was a 71‒year‒old male. Because of paraaortic lymph node metastasis, we initiated intensive chemotherapy with S‒1, oxaliplatin, and trastuzumab. After 6 courses, CT examination revealed that the size of the primary tumor decreased, suggesting a complete response(CR). Furthermore, the metastatic lymph nodes decreased in both number and size, suggesting a partial response(PR). We continued chemotherapy, changing to S‒1 and trastuzumab only because of Grade 3 neutropenia, and conducted continuous infusion chemotherapy. After 5 courses, we performed an upper gastrointestinal endoscopy. The primary tumor recurred, suggesting a progressive disease(PD), while metastasis to the paraaortic lymph nodes disappeared. We decided that a curative resection was possible and performed distal gastrectomy with D2 and paraaortic lymph node dissection. The postoperative courses were uneventful, and the patient was discharged from the hospital 12 days postoperation. The patient is well without any recurrence of cancer at 1 year 3 months postoperation. Conversion therapy may offer the possibility of prolonged survival for patients with gastric cancer previously considered unresectable.

Establishment of an in-vivo porcine delayed perforation model after duodenal endoscopic submucosal dissection.

OBJECTIVES: Duodenal endoscopic submucosal dissection (ESD) for superficial non-ampullary duodenal epithelial tumors has a significant incidence rate of delayed perforation. Although several methods have been proposed to prevent delayed perforation, the most appropriate methods remain unclear. Currently, there is no appropriate animal model to validate methods for preventing duodenal delayed perforation. This study aimed to establish an in-vivo porcine delayed perforation model after duodenal submucosal dissection. METHODS: Two porcine models underwent either ESD or surgical submucosal dissection. In the surgical dissection model, an inverted duodenal mucosa was resected with electrosurgical energy. In the ESD model, a gauze was placed behind the duodenum with grasped transverse part to improve endoscopic maneuverability. The mucosal defects after dissection were treated with omental coverage without suture in both models. All models were euthanized 0-5 days after procedure. Body weight; resection size; procedure dissection time; presence of intraoperative perforation and delayed perforation; and adhesion score were assessed. RESULTS: There were no significant differences in body weight and adhesion score between the two models. Resection size was significantly larger in the surgical dissection models than in the ESD models (19 mm vs 14.3 mm, P < 0.01). Procedure time was significantly longer in the ESD models than in the surgical models (45.2 minutes vs 4.5 minutes, P < 0.01). Delayed perforation rates in the surgical dissection models and the ESD models were 0% (0/5) and 100% (5/5), respectively (P < 0.01). CONCLUSIONS: This study indicated that our in-vivo porcine duodenal ESD model is beneficial to evaluate a prevention strategy for delayed perforation.

Downstaging and Histological Effects Might Be Reliable Predictors of the Efficacy of DOC+CDDP+5-FU (DCF) as Neoadjuvant Therapy for Stage III or Borderline Resectable Esophageal Cancer: a Single Institute Experience.

PURPOSE: In Japan, two courses of CDDP+5-FU (CF) therapy followed by surgery are accepted as a standard treatment for stage II/III esophageal cancer (EC) based on the results of the JCOG9907 trial. To gain a better survival, benefit especially for stage III patients in comparison with CF therapy, a three-arm phase III trial (neoadjuvant setting: CF vs. CF + radiation vs. DOC+CF [DCF]) is ongoing. We have aggressively performed DCF therapy for stage III or IV patients since October 2014. We herein review the outcomes of DCF therapy. METHODS: We retrospectively reviewed the cases of 27 patients with stage III or IV EC (male, n = 24; female, n = 3; median age, 70.0 years) who received DCF therapy. RESULTS: The response rate was 48.1%. Downstaging was achieved over the course of treatment in 14 patients (51.9%). Twenty-six patients transitioned to surgery, with 25 receiving R0 resection. DCF-treated patients who achieved downstaging showed significantly longer relapse-free survival (RFS) than those without downstaging (p = 0.0002). DCF-treated patients with a grade ≥ 1b histological effect showed significantly longer RFS than those with a grade < 1b effect (p = 0.0282). The multivariate analysis showed that downstaging was the only factor significantly associated with RFS in DCF-treated patients. CONCLUSIONS: DCF therapy for stage ≥ III esophageal carcinoma is both feasible and effective. These findings suggest that downstaging and the histological effect might predict the effects of DCF therapy for EC.

The Efficacy of Autologous Myoblast Sheet Transplantation to Prevent Perforation After Duodenal Endoscopic Submucosal Dissection in Porcine Model.

The recent advent of endoscopy has enabled the endoscopic submucosal dissection (ESD) of superficial nonampullary duodenal epithelial tumors. However, the substantially thin wall and presence of bile and pancreatic juice make it technically difficult to perform duodenal ESD without perforation, which leads to lethal complications. The present study evaluated the efficacy of autologous myoblast sheet transplantation for the prevention of late perforation after duodenal ESD in a porcine model. Two weeks before ESD, skeletal muscle was surgically excised from the femur of pigs, and myoblasts were isolated and seeded in temperature-responsive culture dishes to prepare sheets. Immediately after ESD, the autologous myoblast sheets were attached to the serosal surface at the ESD site with omentopexy. The pigs were divided into two groups: the autologous myoblast sheet group (n = 5), where the myoblast cell sheet was attached to the ESD ulcer part from the duodenal serous side, and the Omentum group (n = 5), where only the omentum was used. The pigs were sacrificed and analyzed macroscopically and histologically on postoperative day 3. The macroscopic examination of the abdominal cavity revealed perforation in the ESD ulcer area and leakage of bile in the Omentum group but no perforation in the Sheet group. A histopathological examination revealed that continuity of the duodenal wall at the ESD site was maintained with dense connective tissue in the Sheet group. In conclusion, autologous myoblast sheets were useful for preventing perforation after duodenal ESD.

Living donor liver transplantation for congenital absence of portal vein in portal venous reconstruction with a great saphenous vein graft.

BACKGROUND: Congenital absence of portal vein (CAPV) is a rare structural anomaly in which the portal vein (PV) blood that normally flow into the liver directly drains into the systemic venous system through other collateral circulation. Congenital portal vein shunts (CPSs) is classified into types I and II according to the absence or presence of the intrahepatic portal vein, respectively. The CPS type I is also known as CAPV. The liver transplantation may be the only treatment option for CAPV. The key point of liver transplantation for CAPV is the reconstruction of the PV. CASE PRESENTATION: A 29-year-old man was diagnosed with CAPV with splenomegaly and gastroesophageal varix when being treated for pancytopenia and liver dysfunction. A living donor liver transplantation was performed for him using the right lobe which had been donated by his mother. The PV was reconstructed using his own great saphenous vein (GSV) as a graft vein. The end of the GSV graft was anastomosed to the inferior mesenteric vein while the other end was anastomosed to the vein graft of the right hepatic vein from the explanted liver. CONCLUSION: Using the patient's own GSV for PV reconstruction during living donor transplantation in the patient with CAPV seems to be an effective method.

Ameliorated healing of biliary anastomosis by autologous adipose-derived stem cell sheets.

INTRODUCTION: Cell sheets consisting of adipose-derived stem cells (ADSCs) have been reported to be effective for wound healing. We conducted this study to clarify the efficacy of ADSC sheets in wound healing at the duct-to-duct biliary anastomotic site in pigs. METHODS: Eleven female pigs (20-25 kg) were divided into two groups: biliary anastomosis with an ADSC sheet (n = 6) or without an ADSC sheet (n = 5). To follow the transplanted ADSCs, PKH26GL-labeled sheets were used in one of the ADSC pigs. Two weeks prior to laparotomy, ADSCs were isolated from the lower abdominal subcutaneous adipose tissue. After three passages, ADSCs were seeded on temperature-responsive culture dishes and collected as cell sheets. ADSC sheets were gently transplanted on the anastomotic site. We evaluated specimens by PKH26GL labeling, macroscopic changes, infiltration of inflammatory cells, and collagen content. RESULTS: Labeled ADSCs remained around the bile duct wall. In the no-ADSC group, more adhesion developed at the hepatic hilum as observed during relaparotomy. Histopathological examination showed that the diameter and cross-sectional area of the bile duct wall were decreased in the ADSC group. In the no-ADSC group, a large number of inflammatory cells and more collagen fibers were identified in the bile duct wall. CONCLUSIONS: The present study demonstrated that autologous ADSC sheet transplantation reduced hypertrophic changes in the bile duct wall at the anastomotic site. A long-term follow-up is required to evaluate the efficacy of this mechanism in prevention of biliary anastomotic strictures.

Partial portal vein arterialization during living-donor liver transplantation: a case report.

BACKGROUND: Hepatic artery thrombosis can lead to graft loss associated with severe hepatic infarction or bile duct ischemia. When anatomical hepatic artery reconstruction is impossible in liver transplantation or hepato-pancreatic biliary surgery, portal vein arterialization (PVA) is proposed as a salvage technique. Herein, we report our experience with a case that showed favorable clinical outcomes after partial PVA during living-donor liver transplantation (LDLT) because of difficulties in arterial reconstruction. CASE PRESENTATION: A 62-year-old woman with non-B, non-C liver cirrhosis complicated with hepatocellular carcinoma was being prepared for LDLT using an extended left lobe graft. The graft presented with two arteries (left hepatic artery, 2 mm; middle hepatic artery, 2 mm). The first anastomosis was performed using the recipient hepatic artery stumps, but no flow was detected on Doppler control because of thrombus formation. The next attempt was executed using the middle colic artery with a radial artery jump graft and the right gastroepiploic artery, but it led to the same result. Thus, the graft oxygen support by the standard arterial procurement was abandoned, and a shunt was created between the ileocecal artery and the vein to obtain PVA. Arteriography of the superior mesenteric artery showed that the shunt was relatively patent, and the portal vein was apparent. No biliary complication or liver abscess occurred postoperatively, and the patient presented with good liver function and no complications related to portal vein hypertension, nor liver fibrosis 18 months after the LDLT. CONCLUSION: Partial PVA with a shunt created between the ileocecal artery and the vein is useful when arterial reconstruction is difficult during LDLT for preventing graft loss caused by severe hepatic infarction or bile duct ischemia.

Complete laparoscopic duodenojejunostomy for superior mesenteric artery syndrome: Linear stapled closure of the common enterotomy.

Superior mesenteric artery syndrome can lead to duodenal obstruction due to vascular compression. We treated a patient with superior mesenteric artery syndrome by performing a complete laparoscopic duodenojejunostomy with a linear stapled closure of the common enterotomy. A 72-year-old woman presented with nausea, vomiting, and weight loss. CT revealed superior mesenteric artery syndrome. Conservative management was not effective. Because the patient required a surgical bypass for long-term relief, a laparoscopic duodenojejunostomy was performed. In past cases, hand-sewn sutures were made through a small incision to avoid stenosis when the common enterotomy was closed. For our patient, we closed the common enterotomy with a linear stapler in a complete laparoscopic maneuver. We performed the closure after placing several temporary sutures to minimize the amount of intestinal wall to be removed. Laparoscopic duodenojejunostomy is a minimally invasive procedure, and a linear stapled closure of a common enterotomy is a safe surgical technique that reduces invasiveness.

Stent treatment for huge aneurysm of the common hepatic artery: A case report.

OBJECTIVE/BACKGROUND: Huge aneurysm of the visceral artery is rare and a treatment strategy for such cases has not yet been established. Here, we report a case of huge aneurysm of the common hepatic artery (44-mm diameter) successfully treated by stent placement. METHODS: A 77-year-old female patient was referred to our department due to growth of the common hepatic artery aneurysm. The cause of the aneurysm was suspected to be segmental arterial mediolysis. Due to the possibility of a spontaneous rupture, we decided to stent the common hepatic artery. RESULT: We had some difficulties during the procedure, such as thrombosis of the stent, and it was necessary to insert an additional stent. The procedure was effective and the patient has been doing well without any complications at the 6-year follow-up. CONCLUSION: Stenting is possible and effective in cases of huge aneurysm of the common hepatic artery.

Autologous adipose-derived stem cell sheets enhance the strength of intestinal anastomosis.

OBJECTIVE: Adipose-derived stem cells (ASCs) are capable of multiple differentiation pathways, imparting immunomodulatory effects, and secreting factors that are important for wound healing. These characteristics can be exploited to decrease the incidence of anastomotic leakage. METHODS: In order to delay local wound healing at the anastomotic site, we induced ischemia in a portion of porcine small intestine by ligating vessels. Then, we injected mitomycin C into the serosa of the small intestine above the ligated vessels. Anastomotic sites were created by 2 cm incisions made in the opposite mesenteric area. ASCs were isolated from the porcine subcutaneous fat tissues and expanded under culture conditions. ASCs were trypsinized and seeded on temperature-responsive dishes and cultured to form confluent sheets. Three ASC sheets were transplanted onto the serous membrane after suturing. The extent of anastomotic wound healing was evaluated by bursting pressure, hydroxyproline content, and mRNA expression of collagen-1 alpha1 and collagen-3 alpha1. RESULTS: We found that transplantation of ASC sheets increased anastomotic site bursting pressure. Additionally, transplantation of ASC sheets increased the hydroxyproline content of the anastomoses. Furthermore, transplantation of ASC sheets increased mRNA expression of collagen-1 alpha1 and collagen-3 alpha1. CONCLUSIONS: Our findings showed that transplantation of autologous ASC sheets enhanced collagen synthesis and anastomotic strength. Further studies are necessary to identify substances that, in combination with ASC sheets, might enhance collagen synthesis and healing in sites of anastomosis.