Long term outcomes of abdominal wall reconstruction using open component separation and biologic mesh in the liver, kidney, and small bowel transplant population.

PURPOSE: The aim of this study is to critically examine the multidisciplinary approach to abdominal wall reconstruction (AWR) in the solid organ transplant (SOT) population at our institution, MedStar Georgetown University Hospital, using a modified component separation technique (CST). METHODS: A retrospective review of AWR utilizing modified open CST with biologic mesh in SOT patients was performed from January 2010 to June 2018. Patient demographics, comorbidities, operative details, complications, and outcomes were recorded. Descriptive statistics, logistic and linear regression analyses were performed to appraise outcomes. RESULTS: Thirty-five patients were included; mean age was 53 years. Patient demographics and comorbidities were: 82.9% male, 45.7% history of tobacco use, and 28.6% diabetes. Fifty-one percent had undergone prior hernia repair. Transplant types were: kidney (9), liver (16), liver/kidney (1), small bowel (7), multivisceral (2). All were on an immunosuppressive regimen at time of surgery; 22.9% included steroids. Average defect size was 361 cm2. Additional soft tissue procedures were performed in 65.7% (n = 23) of patients. Median time to healing was 29.0 days. Complication rate was 31.4% (n = 11); six patients required reoperation within 90 days. Recurrence rate was 5.7% (n = 2) at mean of follow up of 3.0 years. Additional soft tissue procedures were statistically significant for healing time (p = 0.037). Steroid use was statistically significant for reoperation within 90 days (OR = 12.500; 95% CI 1.694-92.250); however, steroid use was not significant after correction for confounders. CONCLUSION: Modified open CST with biologic mesh is a safe, efficacious approach to complex AWR in the SOT population with recurrence rates comparable to the general population.

Unusual Cystic Fibrosis Transmembrane Conductance Regulator Mutations and Liver Disease: A Case Series and Review of the Literature.

Cystic fibrosis (CF) is caused by a mutation in the CF transmembrane conductance regulator (CFTR) gene, deranging the activity of chloride channels on the epithelial cell surface. Herein we describe end-stage liver disease in 3 infants with rare CFTR gene mutations; 2 of them were heterozygous. Case 1 was a premature male infant with negative CF screening at birth who developed a small bowel obstruction in the neonatal period requiring an ileostomy, with subsequent cholestatic liver disease and portal hypertension. In addition, he was noted to have frequent respiratory infections prompting a sweat test, which was positive. Genetic testing revealed that he was heterozygous for P.1177F. He then underwent a successful liver transplant. Case 2 was a female infant who developed progressive cholestasis with poor weight gain and was found to have neonatal hepatitis on liver biopsy. A sweat test was negative and genetic testing revealed she was heterozygous for CFTR and PEX26 gene mutations. She subsequently developed pneumatosis involving the cecum that was treated conservatively, followed by a successful liver transplant. Case 3 was a male infant who developed progressive liver disease, with liver biopsy showing neonatal hepatitis. He was extensively investigated but had a negative sweat test on repeated studies. Genetic testing revealed that the patient was heterozygous P.K186N-variant in the AKRID1 gene and homozygous P.R75Q-variant in the CFTR gene. Unfortunately, he succumbed to an acute upper gastrointestinal hemorrhage. Rare and unusual CFTR mutations, even in the heterozygous form, may be a feature in otherwise undiagnosed end-stage liver disease of infancy.

Multi-Visceral Transplantation in a 21-Year-Old Man with Prior Pancreatoblastoma.

Organ transplantation in patients with prior malignancy increases the risk of tumor recurrence post-transplantation due to immunosuppression. Only two cases of liver transplantation have so far been reported in children with hepatic metastases from pancreatoblastoma, a rare malignant neoplasm originating from the epithelial exocrine cells of the pancreas. Herein, we describe a case of a successful multi-visceral transplant in a man with intestinal failure after surgical resection of pancreatoblastoma.

Hospital Readmissions After Intestinal and Multivisceral Transplantation.

BACKGROUND: Intestinal transplant recipients require frequent hospital readmission after a successful transplantation, but the reasons for readmission have not been characterized in detail. METHODS: We reviewed our single-center experience to characterize the patterns of readmissions and to identify preventable causes. Among 87 adult patients who received an intestinal or multivisceral transplant, 65 patients (35 males, 30 females; median age, 42 years [range, 19-66]) with a follow-up of at least 1 year were included in this study. Readmissions were defined as any unplanned inpatient hospital stay of 24 hours or longer occurring within 1 year after discharge from the transplantation admission and were classified as early (<1 month) and late (months 2-12) readmissions. RESULTS: Forty-four (68%) patients required early, and 59 (91%) patients required late readmission. A total of 333 readmissions (median, 4 readmissions/patient [0-20]) occurred within the first year post-transplantation; 69 were early (21%) and 264 were late (79%), resulting in a total of 4089 days of hospital stay (median, 7 days/readmission [2-136]). The three most frequent causes of readmission were dehydration, infection, and surgical complications. CONCLUSIONS: These findings suggest that the rate of hospital readmission after intestinal transplantation could potentially be reduced by optimizing fluid balance and hydration status after discharge.

Developments in immunotherapy for gastrointestinal cancer.

Gastrointestinal (GI) cancers are the most commonly occurring cancer worldwide. Colorectal cancer (CRC) is the second and third most commonly diagnosed cancer in women and men, respectively. Despite the advent of screening and the declining incidence of CRC overall, most patients are not diagnosed at an early, localized stage. Due to resistance to chemotherapy, recurrence, and metastatic disease, those diagnosed with advanced disease have only a 12% 5-year survival rate. Given the overwhelming global impact of CRC, the need for advanced therapy is crucial. Targeted immunotherapy in addition to surgical resection, traditional chemotherapy, and radiation therapy is on the rise. For the purpose of this review, we focused on the advances of immunotherapy, particularly in CRC, with mention of research pertaining to particular advances in immunotherapy for other aspects of the GI system. We review basic immunology and the microenvironment surrounding colorectal tumors that lead to immune system evasion and poor responses to chemotherapy. We also examined the way these obstacles are proving to be the targets of tumor specific immunotherapy. We will present current FDA approved immunotherapies such as monoclonal antibodies (mAb) targeting tumor specific antigens, as well as vaccines, adoptive cell therapy, cytokines, and check-point inhibitors. A summation of prior research, current clinical trials, and prospective therapies in murine models help delineate our current status and future strategies on CRC immunotherapy.

Infection among adult small bowel and multivisceral transplant recipients in the 30-day postoperative period.

BACKGROUND: Intestinal transplantation is a potential option for patients with short gut syndrome (SGS), and infection is common in the postoperative period. The aim of our study was to identify the incidence and characteristics of bacterial and fungal infections of adult small bowel or multivisceral (SB/MV) transplantation recipients in the 30-day postoperative period. METHODS: This retrospective chart review assessed the incidence and characteristics of bacterial and fungal infections in patients who underwent SB/MV transplant at our center between April 2004 and November 2008. Patient data were retrieved from computerized databases, flow-charts, and medical records. RESULTS: A total of 40 adult patients with a mean age of 38.7 ± 13.4 years received transplants during this period: 27 patients received isolated SB, 12 received MV, and 1 received SB and kidney. Our immunosuppressive regimen included basiliximab for induction, and tacrolimus, sirolimus, and methylprednisolone for maintenance therapy. The most common indications for transplant were SGS, intestinal ischemia, Crohn's disease, trauma, motility disorders, and Gardner's syndrome. We report a 30-day postoperative infection rate of 57.5% and mean time to first infection of 10.78 ± 8.99 days. A total of 36 infections were documented in 23 patients. Of patients who developed infections, 56.5% developed 1 infection, 30.4% developed 2 infections, and 13% developed 3 infections. The most common site of infection was the abdomen, followed by blood, urine, lung, and wound infection. The isolates were gram-negative bacteria in 49.3%, gram-positive bacteria in 39.4%, and 11.3% were fungi. The most common organisms were Pseudomonas (19%), Enterococcus (15%), and Escherichia coli (13%). Overall, 47% of infections were due to drug-resistant pathogens; 31% of E. coli and Klebsiella species were extended-spectrum beta-lactamase-producing organisms, 36% of Pseudomonas was multidrug resistant (MDR), 75% of Enterococcus was vancomycin resistant, and 100% of Staphylococcus aureus was methicillin resistant. CONCLUSION: These findings demonstrate that bacterial and fungal infections remain an important complication in SB/MV transplant recipients within the early postoperative period. Infections due to MDR organisms have emerged as an important clinical problem in this patient population.

Successful isolated intestinal transplantation in sensitized recipients with the use of virtual crossmatching.

We evaluated virtual crossmatching (VXM) for organ allocation and immunologic risk reduction in sensitized isolated intestinal transplantation recipients. All isolated intestine transplants performed at our institution from 2008 to 2011 were included in this study. Allograft allocation in sensitized recipients was based on the results of a VXM, in which the donor-specific antibody (DSA) was prospectively evaluated with the use of single-antigen assays. A total of 42 isolated intestine transplants (13 pediatric and 29 adult) were performed during this time period, with a median follow-up of 20 months (6-40 months). A sensitized (PRA ≥ 20%) group (n = 15) was compared to a control (PRA < 20%) group (n = 27) to evaluate the efficacy of VXM. With the use of VXM, 80% (12/15) of the sensitized patients were transplanted with a negative or weakly positive flow-cytometry crossmatch and 86.7% (13/15) with zero or only low-titer (≤ 1:16) DSA. Outcomes were comparable between sensitized and control recipients, including 1-year freedom from rejection (53.3% and 66.7% respectively, p = 0.367), 1-year patient survival (73.3% and 88.9% respectively, p = 0.197) and 1-year graft survival (66.7% and 85.2% respectively, p = 0.167). In conclusion, a VXM strategy to optimize organ allocation enables sensitized patients to successfully undergo isolated intestinal transplantation with acceptable short-term outcomes.

Metabolomics of human intestinal transplant rejection.

Surveillance endoscopy with biopsy is the standard method to monitor intestinal transplant recipients but it is invasive, costly and prone to sampling error. Early noninvasive biomarkers of intestinal rejection are needed. In this pilot study we applied metabolomics to characterize the metabolomic profile of intestinal allograft rejection. Fifty-six samples of ileostomy fluid or stool from 11 rejection and 45 nonrejection episodes were analyzed by ultraperformance liquid chromatography in conjunction with Quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS). The data were acquired in duplicate for each sample in positive ionization mode and preprocessed using XCMS (Scripps) followed by multivariate data analysis. We detected a total of 2541 metabolites in the positive ionization mode (mass 50-850 Daltons). A significant interclass separation was found between rejection and nonrejection. The proinflammatory mediator leukotriene E4 was the metabolite with the highest fold change in the rejection group compared to nonrejection. Water-soluble vitamins B2, B5, B6, and taurocholate were also detected with high fold change in rejection. The metabolomic profile of rejection was more heterogeneous than nonrejection. Although larger studies are needed, metabolomics appears to be a promising tool to characterize the pathophysiologic mechanisms involved in intestinal allograft rejection and potentially to identify noninvasive biomarkers.

Abnormal CX3CR1⁺ lamina propria myeloid cells from intestinal transplant recipients with NOD2 mutations.

Although progress has been made in intestinal transplantation, chronic inflammation remains a challenge. We have reported that the risk of immunological graft loss is almost 100-fold greater in recipients who carry any of the prevalent NOD2 polymorphisms associated with Crohn's disease, and have shown that the normal levels of a key antimicrobial peptide produced by the Paneth cells of the allograft, fall as the graft becomes repopulated by hematopoietic cells of the NOD2 mutant recipient. These studies are extended in this report. Within several months following engraftment into a NOD2 mutant recipient the allograft loses its capacity to prevent adherence of lumenal microbes. Despite the significantly increased expression of CX3CL1, a stress protein produced by the injured enterocyte, NOD2 mutant CX3CR1(+) myeloid cells within the lamina propria fail to exhibit the characteristic morphological phenotype, and fail to express key genes required expressed by NOD2 wild-type cells, including Wnt 5a. We propose that the CX3CR1(+) myeloid cell within the lamina propria supports normal Paneth cell function through expression of Wnt 5a, and that this function is impaired in the setting of intestinal transplantation into a NOD2 mutant recipient. The therapeutic value of Wnt 5a administration in this setting is proposed.

Autotransplantation of solitary kidney with renal artery aneurysm treated with laparoscopic nephrectomy and ex vivo repair: a case report.

INTRODUCTION: Renal artery aneurysms (RAA) are extremely rare clinical entities with associated morbidities including hypertension and rupture. Although most RAA can be treated with in vivo repair or endovascular techniques, these may not be possible in patients with complex RAA beyond the renal artery bifurcation. We report a case of RAA in a patient with a solitary kidney that we treated successfully by extracorporeal repair and autotransplantation and the 2-years follow-up. CASE REPORT: A 64-year-old woman with a history of right nephrectomy for renal cell carcinoma presented with RAA found on routine computed tomography (CT). Preoperative workup demonstrated a 2.2 × 2.1 × 3-cm aneurysm in the distal left renal artery that was not amendable to in vivo or endovascular repair. The patient underwent a laparoscopic-assisted left nephrectomy, ex vivo renal artery aneurysm repair, and autotransplantation. She did well postoperatively and in clinic follow-up was found to have a creatinine of 1.2 mg/dL at the end of 2 years and stable blood pressure control. DISCUSSION: This patient with RAA in her solitary kidney was successfully treated with laparoscopic-assisted nephrectomy, ex vivo repair, and autotransplantation. Her creatinine was stable postoperatively despite absence of a second kidney.

Complex arterial reconstruction in multivisceral transplantation.

We report the case of a successful multivisceral transplant in which both donor and recipient presented aberrant anatomy of the celiac-mesenteric axis requiring five separate arterial anastomoses to reconstruct the blood inflow to the graft.

Nonhemolytic passenger lymphocyte syndrome: donor-derived anti-M in an M+ recipient of a multiorgan transplant.

Passenger lymphocyte syndrome (PLS) is a well-recognized complication that may follow a hematopoietic progenitor cell or solid-organ transplant. Typically, the syndrome presents as acute hemolysis of the recipient's RBCs, which have become serologically incompatible with blood group antibodies formed by passively transfused donor-origin B lymphocytes. Most cases involve anti-A or anti-B. However, there are cases involving non-ABO serologic incompatibility, as well as cases in which the serologic incompatibility was not associated with clinical evidence of hemolysis. This report describes a case of passenger lymphocyte syndrome in an M+ recipient who developed anti-M after receiving a multiorgan transplant from an M- cadaver donor. Although the temporal events and serologic findings were consistent with a diagnosis of PLS, there was no evidence of in vivo hemolysis associated with the identification of a newly formed anti-M. This report includes a literature review of other case reports of PLS associated with non-ABO antibodies in solid-organ and hematopoietic progenitor cell transplant recipients.

Rejection reversibly alters enteroendocrine cell renewal in the transplanted small intestine.

Acute small intestinal allograft rejection presents clinically as an abrupt increase in ileal fluid output in the absence of extensive inflammation. We questioned whether acute intestinal rejection might be accompanied by a disturbance of normal intestinal stem cell differentiation. We examined the intestinal epithelial secretory cell lineage among patients experiencing early rejection before and during rejection as well as following corrective therapy. Lineage-specific progenitors were identified by their expression of stage-specific transcription factors. Progenitors of the enteroendocrine cell (EEC) expressing neurogenin-3 (NEUROG3) were found to be disproportionately reduced in numbers, along with their more mature EEC derivatives expressing neuro D; the enteric hormone PYY was the most profoundly depleted of all the EEC products evaluated. No change in the numbers of goblet or Paneth cells was observed. Steroid treatment resulted in resolution of clinical symptoms, restoration of normal patterns of EEC differentiation and recovery of normal levels of enteric hormones. Acute intestinal rejection is associated with a loss of certain subtypes of EEC, most profoundly, those expressing PYY. Deficiency of the mature EECs appears to occur as a consequence of a mechanism that depletes NEUROG3 EEC progenitors. Our study highlights the dynamics of the EEC lineage during acute intestinal rejection.

Impact of positive preoperative surveillance blood cultures from chronic indwelling catheters in cadaveric intestinal transplant recipients.

Recurrent bloodstream infections are a common indication for intestinal transplantation (ITx). Often, clinical symptoms may be absent in the setting of bacteremia, especially in patients with chronic liver disease. This study investigated the incidence and impact of positive blood cultures (BCx) obtained from central venous catheters used for total parenteral nutrition (TPN) in asymptomatic patients immediately prior to cadaveric ITx. Of 13 consecutive patients transplanted between November 2003 and November 2004, 12 underwent preoperative surveillance BCx with four positives (33%). Isolates included Staphylococcus epidermidis (n = 2), methicillin-resistant Staphylococcus aureus, and Citrobacter freundii. All four patients with positive BCx displayed liver dysfunction at the time of transplant (> or = grade 2 fibrosis, total bilirubin >8.0 g/dL), three of whom were inpatients. In contrast, only three of eight nonbacteremic patients showed liver disease of comparable severity. Liver dysfunction and inpatient status at the time of transplant appear to predict positive blood cultures. Postoperative length of stay and time on the ventilator were significantly longer among bacteremic as compared with nonbacteremic patients, but there were no differences in intraoperative blood use, time to total parenteral nutrition independence, or operative time between bacteremic and nonbacteremic patients. Our study showed that occult bacteremia in asymptomatic pre-intestinal transplant patients was not uncommon and may increase postoperative morbidity. Preemptive removal of long-term central venous catheters should be considered prior to ITx.

Management of a small bowel transplant with complicated central venous access in a patient with asymptomatic superior and inferior vena cava obstruction.

During the past few years, small bowel transplantation (SBT) has become a realistic alternative for patients with irreversible intestinal failure who have or will develop severe complications from total parenteral nutrition (TPN). Transplantation can be associated with large fluid shifts and massive blood loss necessitating rapid infusions of large quantities of crystalloid and/or blood products. Invasive monitoring and large-bore venous access are necessary in order to manage these patients intraoperatively. Because patients with irreversible intestinal failure are often managed with total parenteral nutrition via a central venous catheter, thrombotic intraluminal obstruction of major vessels may develop over time. Additionally, this may lead to superior vena cava (SVC) syndrome as well as challenging problems with vascular access. We present a 34-year-old woman with a past medical history for long-standing Crohn's disease with multiple small bowel resections and short gut syndrome who presented for an SBT. The patient had a long history of TPN use, complicated by SVC syndrome and inferior vena cava (IVC) obstruction. She was presently asymptomatic from her SVC obstruction. Central venous access was obtained by an interventional radiologist. A 7-French double-lumen Hickman minicatheter was placed in the left femoral vein with the tip of the catheter positioned just distal to the IVC narrowing. A left radial 20-gauge arterial line was placed for hemodynamic monitoring and frequent blood sampling. The patient's left and right dorsal-saphenous veins were cannulated with 16-guage catheters and adequate flow was observed. Lower extremity pressure was measured via the Hickman catheter in the left femoral vein. A multiplane transesophageal echo was used to assess ventricular volume. The options and intraoperative management of such patients are discussed.

A simple new formula to assess liver weight.

INTRODUCTION: In cadaveric or segmental liver transplantation, accurate assessment of graft volume is desirable but not always easy to achieve based on donor morphometric data. We sought to establish a simple, reliable formula for accurate prediction of liver volume. METHODS: Data from 1,413 cadaveric adult and pediatric liver donors were analyzed using simple and multiple regression analysis. Liver weight (LW) was plotted against age, height, body weight (BW), body surface area (BSA) or body mass index (BMI); a formula was developed using simple regression: LW (g) = 772 (g/m(2)) x BSA, r = 0.73, P <.01. For donors with BSA 1.0, there was no significant difference between the actual and the estimated mean LW as calculated by the new formula. For pediatric donors, there was no significant difference between estimated and actual mean liver weight with any formula. When the new formula was applied, the difference between the actual and the estimated liver weight was acceptable (<20%) in 1040 (73.6%) cases. In all races, there was no significant difference between actual and estimated mean liver weight as calculated by this formula. CONCLUSIONS: A simple formula to calculate liver weight in donors with BSA >1.0 is: LW = 772 x BSA, and for donors with BSA

Critical graft size in adult-to-adult living donor liver transplantation: impact of the recipient's disease.

The aim of this study is to analyze the impact of the recipient's disease severity on graft size requirements and outcome in adult-to-adult living donor liver transplantation. A limiting factor in adult-to-adult living donor liver transplantation has been adequacy of graft size. A minimal graft-recipient weight ratio (GRWR) of 0.8% to 1% has been suggested, without taking the recipient's disease into account. Forty adults underwent liver transplantation using left (n = 10; mean weight, 481 +/- 83 g) or right lobes (n = 30; mean weight, 845 +/- 182 g). We recorded graft survival, Child-Turcotte-Pugh score, and occurrence of small-for-size syndrome (poor bile production, prolonged postoperative prothrombin time, and cholestasis without ischemia markers). Small grafts were defined as GRWR of < or =0.85%. Large grafts were defined as GRWR greater than 0.85%. Six patients died within 6 months of transplantation (early patient survival rate, 85%); two patients died late of tumor recurrence. Among transplant recipients with normal liver function or Child's class A, there was no significant difference with the use of small (n = 6) or large (n = 9) grafts (graft survival rates, 83% v 88%, respectively; P =.65). Among patients with Child's class B or C, graft survival rates were 74% in recipients of large grafts (n = 19) and 33% in recipients of small grafts (n = 6; P =.023). Five of 6 patients with Child's class B or C who received small grafts developed small-for-size syndrome; 2 patients died (1 patient after retransplantation) and 3 patients survived (2 patients after retransplantation). Graft function and survival are influenced not only by graft size, but also by pretransplantation disease severity. GRWR as low as 0.6% can be used safely in patients without cirrhosis or in patients with Child's class A. Transplant recipients with Child's class B or C require a GRWR greater than 0.85% to avoid small-for-size syndrome and related complications.