Complex Abdominal Wall Reconstruction with Biologic Mesh for Ventral/Umbilical Hernias in Patients with Cirrhosis: Technique and Outcomes.

INTRODUCTION: Patients with cirrhosis undergoing non-liver transplant surgery have a higher risk or adverse events than those without cirrhosis. The main objectives of this study were to describe characteristics, outcomes, and outcome predictors of cirrhotic patients undergoing complex abdominal wall reconstruction (CAWR) with biologic mesh. MATERIALS AND METHODS: This study had retrospective and prospective components, including all cirrhotic patients at our center with CAWR for ventral/umbilical hernia repair with biologic mesh between December 2016 and November 2021. RESULTS: We studied 37 patients with cirrhosis. Their mean age was 57.2 years, and 64.9% were male. The median body mass index (BMI) was 28.1kg/m2. Ascites was present in 83.3% of patients. The other most common comorbidities were alcohol abuse (67.6%), hypertension (37.8%), and diabetes (24.3%). All complications in aggregate occurred in 11 patients (29.7%). Six patients (16.2%) underwent reoperation. Surgical site infections (SSIs) occurred in five patients (13.5%). Four deaths occurred within 90 days (11.2% cumulative mortality). By 120 days, there were five deaths (14.2% mortality, but none due to the operation). Seven predictor variables achieved an area under the receiver operating characteristic curve (AUROC) for SSI of 0.963, and two predictors yielded an AUROC of 0.825 for 120-day mortality. CONCLUSIONS: Our results suggest that CAWR for ventral/umbilical hernias among cirrhotic patients is feasible given a dedicated CAWR team in collaboration with transplant surgeons and a transplant hepatologist. The rates of adverse outcomes were low or at the midpoint of the range of the study-specific estimates.

Early Drain Removal--The Middle Ground Between the Drain Versus No Drain Debate in Patients Undergoing Pancreaticoduodenectomy: A Prospective Validation Study.

OBJECTIVE: To perform an unbiased assessment of first postoperative day (POD 1) drain amylase level and pancreatic fistula (PF) after pancreaticoduodenectomy (PD). BACKGROUND: Recent evidence demonstrated that drain abandonment in PD is unsafe. Early drain amylase levels have been proposed as predictors of PF after PD, allowing for selection of patients for early drain removal. METHODS: Daily drain amylase levels were correlated with the development of PF in 2 independent cohorts of patients undergoing PD: training cohort (n = 126; year 2008) and validation cohort (n = 369; years 2009-2012). RESULTS: POD 1 drain amylase level had the highest predictive ability (concordance index: 0.911) for PF in the training cohort. An amylase level of 612 U/L or higher showed the best accuracy (86%), sensitivity (93%), and specificity (79%). Thus, a cutoff value of 600 U/L was utilized. In the validation cohort, 229 (62.1%) patients had a POD 1 drain amylase level of lower than 600 U/L, and PF developed in only 2 (0.9%) cases; whereas in patients with POD 1 drain amylase level of 600 U/L or higher (n = 140) the PF rate was 31.4% (odds ratio [OR] = 52, P < 0.0001). On multivariate analysis, POD 1 drain amylase level of lower than 600 U/L (OR = 0.0192, P < 0.0001) was a stronger predictor of the absence of PF than pancreatic gland texture (OR = 0.193, P = 0.002) and duct diameter (OR = 0.861, P = 0.835). CONCLUSIONS: After PD, the risk of PF is less than 1% if POD 1 drain amylase level is lower than 600 U/L. We propose that in this group, which comprise more than 60% of patients, drains should be removed on POD 1.

Up to 9-day survival and control of thrombocytopenia following alpha1,3-galactosyl transferase knockout swine liver xenotransplantation in baboons.

BACKGROUND: With standard miniature swine donors, survivals of only 3 days have been achieved in primate liver-transplant recipients. The recent production of alpha1,3-galactosyl transferase knockout (GalT-KO) miniature swine has made it possible to evaluate xenotransplantation of pig organs in clinically relevant pig-to-non-human primate models in the absence of the effects of natural anti-Gal antibodies. We are reporting our results using GalT-KO liver grafts. METHODS: We performed GalT-KO liver transplants in baboons using an immunosuppressive regimen previously used by our group in xeno heart and kidney transplantation. Post-operative liver function was assessed by laboratory function tests, coagulation parameters and histology. RESULTS: In two hepatectomized recipients of GalT-KO grafts, post-transplant liver function returned rapidly to normal. Over the first few days, the synthetic products of the donor swine graft appeared to replace those of the baboon. The first recipient survived for 6 days and showed no histopathological evidence of rejection at the time of death from uncontrolled bleeding, probably caused by transfusion-refractory thrombocytopenia. Amicar treatment of the second and third recipients led to maintenance of platelet counts of over 40 000 per µl throughout their 9- and 8-day survivals, which represents the longest reported survival of pig-to-primate liver transplants to date. Both of the last two animals nevertheless succumbed to bleeding and enterococcal infection, without evidence of rejection. CONCLUSIONS: These observations suggest that thrombocytopenia after liver xenotransplantation may be overcome by Amicar therapy. The coagulopathy and sepsis that nevertheless occurred suggest that additional causes of coagulation disturbance must be addressed, along with better prevention of infection, to achieve long-term survival.

Autoimmune sensitization to cardiac myosin leads to acute rejection of cardiac allografts in miniature swine.

BACKGROUND: Recent studies in mice and patients suggest that posttransplantation induction of autoimmune responses to tissue-specific antigens contributes to the rejection of major histocompatibility complex mismatched allotransplants. The relevance of this phenomenon to the rejection of major and minor histocompatibility-mismatched allografts performed in large-animal models remains to be established. METHODS: Miniature swine were immunized with cardiac myosin (CM) in Freund's adjuvant and received heterotopic, minor antigen-mismatched heart transplants. T-cell (proliferation and delayed type hypersensitivity [DTH]) and B-cell (antibody) responses specific to CM were measured. The rejection of heart transplants was assessed histologically. RESULTS: Three of four swine that were immunized with CM before receiving a minor antigen-mismatched heart transplant exhibited potent DTH, T-cell proliferation and antibody responses to CM and rejected their grafts acutely. The fourth swine, which failed to mount a significant DTH response to CM and displayed low and transient anti-CM antibody titers, demonstrated long-term allograft survival. CONCLUSIONS: This large-animal study supports the relevance of autoimmunity to CM in the rejection of minor antigen disparate cardiac allotransplants.

Repetitive gastric aspiration leads to augmented indirect allorecognition after lung transplantation in miniature swine.

INTRODUCTION: Lung transplant recipients with documented gastroesophageal reflux disease (GERD) are at increased risk for graft dysfunction. Here, we present the first large-animal model of gastric aspiration after allogeneic lung transplantation and some preliminary data demonstrating the effect of chronic aspiration on the direct and indirect pathways of allorecognition. METHODS: Left orthotopic lung transplants (n=3) were performed in miniature swine across a major histocompatibility complex class I disparity, followed by 12 days of high-dose cyclosporine A. At the time of transplantation, a transtracheal catheter was placed at the carina, above the bronchial anastomosis. A gastrostomy tube was placed for daily aspiration of gastric contents. Subsequently, graft lungs were instilled with gastric aspirate daily (3 mL/hrX8 hr/day) for 50 days. Recipients were followed up with daily complete blood count, scheduled chest radiographs, and biopsies. In vitro studies, including cell-mediated lympholysis, mixed lymphocyte reactions, and peptide proliferation assays, were performed. Results from these three recipients were compared with those of historical controls (n=6) who were treated identically, except for the tracheal cannulation and simulated gastric aspiration. RESULTS: Two of the experimental animals were euthanized with nonviable lungs soon after the postoperative day 50 biopsy. In both cases the native lung was normal. The third animal survived over 180 days without the evidence of chronic rejection. After immunosuppressive treatment, all animals demonstrated donor-specific hyporesponsiveness by assays of direct alloresponse (cell-mediated lympholysis, mixed lymphocyte reaction). A significant response to synthetic donor-derived class I peptide, however, was seen in all animals. A more pronounced and diffuse response was seen in the animals rejecting their grafts. The historical controls showed medium-term graft survival with evidence of chronic rejection in the majority of animals, as previously reported. CONCLUSION: In a model of GERD after lung transplantation, a spectrum of clinical outcomes was observed. The in vitro data suggest that acid reflux enhances the indirect alloresponse to processed donor class I antigen, giving mechanistic insight into the manner in which GERD may be deleterious to the transplanted lung.