Association between artificial nutrition in brain dead donors and early allograft function in liver transplant recipients: an observational study.

BACKGROUND: The role of nutrition in donor after brain deaths (DBDs) has yet to be adequately discussed. The primary aim of this study was to investigate whether the nutritional intake in the 48 h before organ retrieval may play a role on the graft functional recovery assessed with Model for Early Allograft Function (MEAF) Score. METHODS: Single-center retrospective study evaluating all liver transplants performed at the University Hospital of Udine from January 2010 to August 2020. Patients receiving grafts from DBD donors fed with artificial enteral nutrition in the 48 h prior to organ procurement (EN-group) or who did not (No-EN-group). Caloric debt was calculated using the difference between the calculated caloric needs and the effective calories delivered through enteral nutrition. RESULTS: Livers from EN-group presented a lower mean MEAF score compared to the no-EN-group: 3.39 ± 1.46 versus 4.15 ± 1.51, respectively (p = .04). A positive correlation between caloric debt and the MEAF score was found within the overall population (r = .227, p = .043) as well as in EN-group (r = .306, p = .049). CONCLUSIONS: Donor's nutritional intake in the final 48 h before organ procurement correlates with MEAF score, and nutrition probably plays a positive role on the functional recovery of the graft. Large future randomized controlled trials are needed to confirm this preliminary results.

Assessment of hepatic steatosis based on needle biopsy images from deceased donor livers.

BACKGROUND: Assessment of hepatic steatosis (HS) before transplantation requires the pathologist to read a graft biopsy. A simple method based on the evaluation of images from tissue samples with a smartphone could expedite and facilitate the liver selection. This study aims to assess the degree of HS by analysing photographic images from liver needle biopsy samples. METHODS: Thirty-three biopsy-images were acquired with a smartphone. Image processing was carried out using ImageJ: background subtraction, conversion to HSB colour space, segmentation of the biopsy area, and evaluation of statistical features of Hue, Saturation, Brightness, Red, Green, and Blue channels on the biopsy area. After feature extraction, correlations were made with gold standard HS percentage assessed at two levels (frozen-section vs glass-slide). Sensitivity, specificity, and accuracy were calculated for each feature. RESULTS: Correlations were found for H, S, R. The sensitivity, specificity, and accuracy of the final classifier based on the K* algorithm were 94%, 92%, 94%. LIMITATIONS: Accuracy assessment was performed considering macrovesicular steatosis on specimens with mostly < 30% HS. CONCLUSIONS: The steatosis assessment based on needle biopsy images, proved to be an effective and promising method. Deep learning approaches could also be experimented with a larger set of images.

Association between indocyanine green clearance test and ischemic type biliary lesions within one year after orthotopic liver transplantation.

BACKGROUND: Ischemic type biliary lesions (ITBLs), a particular subset of non-anastomotic biliary strictures (NAS), are characterized by intra and extrahepatic strictures that occur in the absence of either hepatic artery thrombosis or stenosis. When they occur within the first year after liver transplantation their development is mostly related to ischemia-reperfusion injury (IRI). The indocyanine green plasma disappearance rate (ICG-PDR) might be able to predict the probability of IRI-induced graft damage after liver transplantation. OBJECTIVE: Our aim was to evaluate the association between ICG-PDR and the occurrence of ITBLs. Secondly, we searched for evidence of IRI in patients presenting ITBLs. METHODS: This retrospective single-center observational study assessed a cohort of 60 liver transplant patients. Each patient underwent ICG-PDR on the 1st postoperative day. ITBLs were identified by means of either cholangiography or magnetic resonance imaging evidence of a deformity and narrowing of the biliary tree in the absence of hepatic artery thrombosis/stenosis. RESULTS: ITBLs were discovered in 10 patients out of 60 liver recipients (16.67%) within one year after transplantation. A low ICG-PDR value was found to be a significant predictive factor for ITBL development, with an OR of 0.87 and a 95% CI of 0.77-0.97. Liver biopsies were performed in 56 patients presenting unexplained abnormal liver function test results. A statistically significant association was found between the development of ITBLs and anatomopathological evidence of IRI. LIMITATIONS: Retrospective, single-center study. CONCLUSIONS: The findings from this study show a relationship between low ICG-PDR values on first post-operative-day and the occurrence of ITBLs within 1 year after transplantation.

Controlling Nutritional Status score does not predict patients' overall survival or hepatocellular carcinoma recurrence after deceased donor liver transplantation.

BACKGROUND: The Controlling Nutritional Status (CONUT) score is a newly developed laboratory-derived immunonutritional score which has been validated as prognostic marker for survival and tumor recurrence in surgically treated patients with various tumor types, including hepatocellular carcinoma (HCC). The aim of the present study was to test the CONUT score performance in HCC patients treated with liver transplantation (LT). METHODS: A retrospective study on a bi-centers cohort of 280 HCC patients submitted to LT between 2006 and 2017 was performed. Indication to LT was limited to Milan criteria or UCSF criteria, defined by preoperative imaging. RESULTS: Median pre-LT CONUT score was 5 (interquartile range 3-7). Overall patients' survival at 1, 3, and 5 years was 84%, 76.6%, and 68.3%, respectively. Multivariate analysis showed that HCC recurrence (hazard ratio [HR] = 1.987, P = .012] and pre-LT neutrophil to lymphocyte ratio (NLR) (HR = 1.064, P = .003) were independent risk factors for reduced survival. Cumulative incidence of HCC recurrence at 1, 3, and 5 years was 5.1%, 11.5%, and 15.5%, respectively. Pre-LT platelet-to-lymphocyte ratio (PLR) (subdistribution hazard ratio [SHR] = 1.086, P = .044], tumor max diameter (SHR = 1.695, P < .001), and bilobar tumor distribution (SHR = 6.892, P = .006) were independent risk factors for tumor recurrence. The CONUT score did not show any prognostic value. CONCLUSIONS: The CONUT score did not predict poor survival or tumor recurrence in LT recipients.

Early post-liver transplant surgical morbidity in HIV-infected recipients: risk factor for overall survival? A nationwide retrospective study.

The aim of the study was to analyse the risk factors for early surgical complications requiring relaparotomy and the related impact on overall survival (OS) in HIV-infected patients submitted to liver transplantation. Thus a retrospective investigation was conducted on a nationwide multicentre cohort of 157 HIV patients submitted to liver transplantation in six Italian Transplant Units between 2004 and 2014. An early relaparotomy was performed in 24.8% of cases and the underlying clinical causes were biliary leak (8.2%), bleeding (8.2%), intestinal perforation (4.5%) and suspect of vascular complications(3.8%). No differences in terms of prevalence for either overall or cause-specific early relaparotomies were noted when compared with a non-HIV control group, matched for MELD, recipient age, HCV-RNA positivity and HBV prevalence. While in the control group an early relaparotomy appeared a negative prognostic factor, such impact on OS was not noted in HIV recipients. Nonetheless increasing number of relaparotomies were associated with decreased survival. In multivariate analysis, preoperative refractory ascites and Roux-en-Y choledochojejunostomy reconstruction were significant risk factors for early relaparotomy. To conclude, in HIV liver transplanted patients, an increasing number of early relaparotomies because of surgical complications does negatively affect the OS. Preoperative refractory ascites reflecting a severe portal hypertension and a difficult biliary tract reconstruction requiring a Roux-en-Y choledochojejunostomy are associated with increased risk of early relaparotomy.

Defining and predicting textbook outcomes for perihilar cholangiocarcinoma: analysis of factors improving achievement of desired postoperative outcomes.

BACKGROUND: Definition of textbook outcome (TO), defined as a single indicator combining the most advantageous short-term outcomes, is still lacking for perihilar cholangiocarcinoma (PHC). The primary endpoint of the present study is to analyze the rate of achievement of a disease-specific TO for PHC within a high volume tertiary referral centre. Secondary endpoints are to identify predictive factors of TO-achievement and to analyze the impact of achieving TO on long-term results. METHODS: Between 2010 and 2022, a total of 237 patients undergoing combined liver and biliary resection for PHC at tertiary referral centre were included. Disease-specific TO were defined as: no 90-day mortality, no postoperative complications, no readmission, no intraoperative transfusions and resection margins. A logistic regression model was developed to identify predictors associated with TO-achievement. Kaplan-Meier curves were designed to determine TO's impact on survival. RESULTS: TO was achieved in 60 (25.3%) patients. At multivariate logistic regression, preoperative biliary drainage [odds ratio (OR) 2.90 (1.13-3.40), P =0.026], high prognostic nutritional index [OR 7.11 (6.71-9.43), P =0.007[ and minimally invasive approach [OR 3.57 (2.31-3.62), P =0.013] were identified as independent predictors of TO. High ASA score [OR 0.38 (0.17-0.82), P =0.013] decreased the odds of TO. A significant improvement in both overall survival and disease-free survival was associated to TO fulfilment. CONCLUSION: Since the achievement of TO correlates with better disease-free and overall survival, every effort should be made to ameliorate modifiable aspects prior to surery: management within referral centres with dedicated experience in biliary tract cancer and preoperative optimization protocol may positively contribute to improve postoperative outcomes, increasing the chance to obtain TO. Moreover, the implementation of advanced minimally invasive programs plays as well.

A rare case of duplication of the descending colon in a pregnant woman: case report and literature review.

INTRODUCTION: Gastrointestinal duplications are uncommon congenital abnormalities that can occur anywhere throughout the intestinal tract. The small bowel is more interested than the large one. Duplications are schematically classified as spherical and tubular, respectively representing 80% and 20% of cases, with different relationships and communications with the native intestinal wall. Although typically diagnosed during infancy and early childhood, tubular colonic sub-type stays frequently hidden for several years until a complication occurs. CASE PRESENTATION: we report the case of a T-shaped tubular duplication in a 20-year-old woman at the 30th week of gestation, who underwent an urgent exploratory laparotomy for intestinal occlusion, treated with the resection of the aberrant large bowel. The patient was notable for a long history of constipation and chronic pain. Diagnostic possibilities were limited by the on-going pregnancy. CONCLUSION: Intestinal duplications are uncommon malformations, and, of these, the T-shaped subtype of the colon is among the rarest ones. In the adulthood, diagnosis is usually established in the operating room during urgent or even emergency surgery performed for abdominal complications. A duplication of the descending colon is extremely rare, and this is, to our knowledge, the only article describing a case found in advanced state of pregnancy.

Re-thinking of T-tube use in whole liver transplantation: an analysis on the risk of delayed graft function.

The liver-gut axis has been identified as crucial mediator of liver regeneration. Thus, the use of a T-tube in liver transplantation (LT), which interrupts the enterohepatic bile circulation, may potentially have a detrimental effect on the early allograft functional recovery. We retrospectively analyzed a cohort of 261 patients transplanted with a whole liver graft, with a duct-to-duct biliary anastomosis, who did not develop any surgical complication within postoperative day 14. Early allograft dysfunction (EAD) was defined according to the criteria of Olthoff et al. (EAD-O), and graded according to the Model for Early Allograft Function (MEAF) score. EAD-O developed in 24.7% of recipients and the median MEAF score was 4.0 [interquartile range 2.9-5.5]. Both MEAF and EAD predicted 90-day post-LT mortality. A T-tube was used in 49.4% of cases (n = 129). After a propensity score matching for donor age, cold and warm ischemia time, donor risk index, balance of risk score, Child-Pugh class C, and MELD score, the T-tube group showed a significantly higher prevalence of EAD-O and value of MEAF than the no-T-tube group (EAD-O: 29 [34.1%] vs 16 [19.0%], p = 0.027; MEAF 4.5 [3.5-5.7] vs 3.7 [2.9-5.0], p = 0.014). In conclusion, T-tube use in LT may be a risk factor for EAD and higher MEAF, irrespective of graft quality and severity of pre-LT liver disease.

Current practice with grafts with multiple renal arteries in kidney transplantation: role of the methylene blue in the lower pole.

Kidneys with multiple renal arteries (MRAs) from different patches, may provide to the surgeon additional technical difficulties that make kidney transplants very challenging. MRAs have been largely debated over the years whether to be anastomosed or not due to the disappointing outcomes when it comes to inappropriate ligation or anastomosis.  Some authors empirically reassure that smaller branches can be safely ligated and dissected without intraoperative and postoperative complications or compromising the functional recovery of the graft. Literature is poor about the possible differences in the management of superior and inferior polar arteries. Inferior polar arteries represent a topic of great interest as they may also supply the proximal ureter. The aim of this article is to merge the current knowledge about the management of inferior polar arteries and to highlight if there is any role of the methylene blue dye (MB) in the study of the ureteral vascularization in kidney transplantation. MB can be considered a safe and simple tool of vascular perfusion assessment in kidney transplantation. By injecting the dye-solution into the inferior MRA hidden ureteral branches can be unmasked and guide the surgeon to preserve important vessels. In view of their fundamental role in the vascularization of the ureter, the lower polar arteries of the graft, should be invariably studied by MB. It provides an objective, simple and fast tool for the evaluation of the ureteral vascularization when injected through the inferior MRA of the graft.

Liver resection for noncolorectal and nonneuroendocrine metastases: results of a study on 56 patients at a single institution.

The usefulness of surgical treatment for hepatic metastases of noncolorectal nonneuroendocrine (NCRNNE) tumors is not yet clear due to the natural history of these tumors, their frequent systemic dissemination and their histological heterogeneity. The aim of this study was to evaluate the long-term outcome of patients who underwent liver resection for NCRNNE metastases. For this purpose we retrospectively analyzed 202 patients who underwent liver resection for metastasis between January 1989 and December 2006 at the Department of Surgery of the University Hospital of Udine. Fifty-six patients underwent liver resection because of NCRNNE metastases. The preoperative assessment was based on hepatic ultrasonography and CT scan; PET was used in a few patients. All patients had intraoperative liver ultrasonography to evaluate the lesions and to define the resection. Gender, age, primary tumor site (gastrointestinal or nongastrointestinal), synchronous or metachronous metastasis, unilobar or bilobar localization, number and diameter of the lesion(s), type of resection, margin status, positive lymph nodes in the hepatoduodenal ligament, and time between surgery and diagnosis of liver metastases were evaluated as possible prognostic factors for survival. Univariate analysis showed that the location of the primary tumor and the disease-free interval since the treatment of the primary tumor were positive predictive factors for longer survival. Multivariate analysis showed that the only independent significant factor was gastrointestinal versus nongastrointestinal origin. Demographic data, the synchronous or metachronous appearance of metastases, their unilobar or bilobar location, number and size, the type of resection, the resection margin status and the involvement of lymph nodes did not prove to be prognostic factors.

Contrast-enhanced ultrasound applications in liver transplant imaging.

Contrast-enhanced ultrasound (CEUS) is gaining ever-increasing acceptance in the preoperative and postoperative evaluation of liver-transplanted patients. While indications are still a matter of research, CEUS is used in tertiary centers to supplement ultrasound (US) and Color Doppler US examination, with the potential of providing a comprehensive first-line ultrasound-based diagnosis. Alternatively, CEUS is used as a problem-solving tool when previous cross-sectional or US imaging was inconclusive, especially in assessing hepatocellular carcinoma, parenchymal perfusion abnormalities, the vascular status, and even the biliary tree. This review describes the potential use for CEUS in the setting of orthotopic liver transplantation (OLT).

The Challenging Management of an Intracardiac Thrombus in a Liver Transplant Patient at the Reperfusion Phase: A Case Report and Brief Literature Review.

The exact origin of intracardiac thrombi formation during orthotopic liver transplant remains unknown. The altered balance between hypercoagulability, hypocoagulation, and endothelial dysfunction associated with end-stage liver disease is thought to play a pivotal role. Venous stasis, vascular clamping, and reperfusion could also contribute to clot formation. The incidence of intracardiac thrombi formation stands at 4.2%, associated with a mortality rate of 45.5%, and to date, no consensus exists regarding the best way to treat this complication. Intraoperative transesophageal echocardiography is the only effective method for diagnosing intracardiac thrombi formation early, while point-of-care coagulation testing could guide the coagulation management potentially improving patient outcomes.

Association between the donor to recipient ICG-PDR variation rate and the functional recovery of the graft after orthotopic liver transplantation: A case series.

BACKGROUND: Despite current advances in liver transplant surgery, post-operative early allograft dysfunction still complicates the patient prognosis and graft survival. The transition from the donor has not been yet fully understood, and no study quantifies if and how the liver function changes through its transfer to the recipient. The indocyanine green dye plasma disappearance rate (ICG-PDR) is a simple validated tool of liver function assessment. The variation rate between the donor and recipient ICG-PDR still needs to be investigated. MATERIALS AND METHODS: Single-center retrospective study. ICG-PDR determinations were performed before graft retrieval (T1) and 24 hours after transplant (T2). The ICG-PDR relative variation rate between T1 and T2 was calculated to assess the graft function and suffering/recovering. Matched data were compared with the MEAF model of graft dysfunction. OBJECTIVE: To investigate whether the variation rate between the donor ICG-PDR value and the recipient ICG-PDR measurement on first postoperative day (POD1) can be associated with the MEAF score. RESULTS: 36 ICG-PDR measurements between 18 donors and 18 graft recipients were performed. The mean donor ICG-PDR was 22.64 (SD 6.35), and the mean receiver's ICG-PDR on 1st POD was 17.68 (SD 6.60), with a mean MEAF value of 4.51 (SD 1.23). Pearson's test stressed a good, linear inverse correlation between the ICG-PDR relative variation and the MEAF values, correlation coefficient -0.580 (p = 0.012). CONCLUSION: The direct correlation between the donor to recipient ICG-PDR variation rate and MEAF was found. Measurements at T1 and T2 showed an up- or downtrend of the graft performance that reflect the MEAF values.

Postoperative Trends and Prognostic Values of Inflammatory and Nutritional Biomarkers after Liver Transplantation for Hepatocellular Carcinoma.

Preoperative inflammatory biomarkers such as the Platelet-to-Lymphocyte Ratio (PLR) and the Neutrophil-to-Lymphocyte Ratio (NLR) strongly predict the outcome in surgically treated patients with hepatocellular carcinoma (HCC), while nutritional biomarkers such as the Controlling Nutritional Status (CONUT) and the Prognostic Nutritional Index (PNI) show an analogue prognostic value in hepatic resection (HR) but not in liver transplant (LT) cases. Data on the impact of LT on the inflammatory and nutritional/metabolic function are heterogeneous. Therefore, we investigated the post-LT trend of these biomarkers up to postoperative month (POM) 12 in 324 HCC patients treated with LT. Inflammatory biomarkers peaked in the early post-LT period but at POM 3 leveled off at values similar (NLR) or higher (PLR) than pre-LT ones. CONUT and PNI worsened in the early post-LT period, but at POM 3 they stabilized at significantly better values than pre-LT. In LT recipients with an overall survival >1 year and no evidence of early HCC recurrence, 1 year post-LT NLR and PNI independently predicted patient overall survival, while 1 year post-LT PLR independently predicted late tumor recurrence. In conclusion, at 1 year post-LT, the nutritional status of liver-transplanted HCC patients significantly improved while their inflammatory state tended to persist. Consequently, post-LT PLR and NLR maintained a prognostic value for LT outcome while post-LT CONUT and PNI acquired it.

Steatosis of the hepatic graft as a risk factor for post-transplant biliary complications.

BACKGROUND: Despite recent advances in organ preservation, immunosuppression, and surgical techniques, the biliary tree is still considered the Achilles' heel of liver transplantation. The aim of this study is to retrospectively analyze the incidence of biliary complications and identify risk factors that might predispose to the development of biliary problems. METHODS: From January 2004 to December 2007, 117 consecutive liver transplantations were retrospectively analyzed for the development of biliary complications by the review of medical records. Patients were divided into group 1 with biliary complications (n = 43) and group 2 without biliary complications (n = 74). RESULTS: The overall biliary complication rate was 36.8% (leakage 6% and stricture 30.8%). Univariate analysis indicated that significant predictors of biliary complications were the time interval between portal and arterial reperfusion (p = 0.037) and macrovacuolar steatosis of the graft > 25% (p = 0.004). Stepwise logistic regression model demonstrated that a macrosteatosis of the graft > 25% (OR = 5.21 CI 95% [1.79-15.15], p = 0.002) was the only independent risk factor predicting biliary complications after liver transplantation. No differences in patient's and graft's survival were noted between the two groups. CONCLUSION: According to our experience, transplanting a liver with > 25% of steatosis is a risk factor for the development of biliary complication.

Can Preoperative Multidetector Computed Tomography Identify Predictive Features of Difficult Native Hepatectomy at Liver Transplantation?

BACKGROUND: Native hepatectomy represents the most demanding surgical step during orthotopic whole liver transplantation (LT). The surgical risk assessment of LT candidates is currently mainly based on clinical and laboratory data, but even preoperative imaging data may be predictive of a complex native hepatectomy. METHODS: A retrospective study on a cohort of 110 LT recipients was conducted. The radiologic variables investigated on pre-LT multidetector computed tomography scan were the length of the retrohepatic inferior vena cava (IVC-L), volume of the dorsal liver sector (DLS-V), complete encirclement of the IVC by the DLS (IVC-CE), max diameter of the native liver (L-D), max diameter of the spleen (S-D), and presence of large spontaneous portosystemic shunts (SPSS). The parameters defining complex native hepatectomy were the operative time, number of red blood cell (RBC) units transfused, IVC replacement technique switch, and post-LT relaparotomy for major bleeding. RESULTS: In a multivariate analysis, the operative time was predicted by hepatocellular carcinoma (HCC) diagnosis (regression coefficient [RC]: 18.237, P = .009), S-D (RC: 3.733, P = .007), and IVC-CE (RC: 20.174, P = .01); the RBC units transfused by an history of gastroesophageal variceal bleeding (RC: 2.503, P = .039), Model for End-Stage Liver Disease (MELD) score (RC: .259, P = .039), and L-D (RC: -0.519, P = .027); the switch to a IVC replacement technique by L-D (odds ratio [OR]: 0.641, P = .028) and IVC-L (OR: 1.065, P = .023); and the relaparotomy for bleeding by L-D (OR: 0.632, confidence interval [CI]: 0.437 to 0.916, P = .015). CONCLUSIONS: Pre-LT multidetector computed tomography (MDCT) seems to be a very useful tool in the surgical risk assessment of LT candidates.

MeltDose Technology vs Once-Daily Prolonged Release Tacrolimus in De Novo Liver Transplant Recipients.

BACKGROUND: An extended-release formulation of tacrolimus designed for once-daily administration (LCP-TAC) is a new prolonged-release tacrolimus (TAC-PR) formulation using a drug delivery technology designed to enhance the bioavailability of drugs compared with TAC-PR. The aim of this study was to retrospectively compare de novo administration of LCP-TAC and TAC-PR for therapeutic trough levels and daily dosage during the first 30 days after first liver transplant (LT). METHODS: A total of 35 patients submitted to first LT between 2016 and 2018 were retrospectively enrolled: 16 received LCP-TAC, while 19 received TAC-PR as de novo immunosuppression. Patients were analyzed for daily dosage and trough levels at postoperative days (PODs) 3, 7, 15, and 30. RESULTS: The initial dose of tacrolimus did not differ between LCP-TAC and TAC-PR (mean, 5.19 [SD, 1.72] mg/d vs mean, 5.26 [SD, 1.91] mg/d, P = .90). On PODs 7, 15, and 30 the daily dosage was statistically lower for LCP-TAC compared with TAC-PR (mean, 5.44 [SD, 2.06] mg/d vs mean, 7.68 [SD, 2.91] mg/d, P = .01; mean, 5.33 [SD, 2.23] mg/d vs mean, 8.82 [SD, 2.35] mg/d, P < .001; and mean, 5.38 [SD, 2.50] mg/d vs mean, 9.81 [SD, 3.78] mg/d, P < .001, respectively). The therapeutic trough levels were significantly higher for LCP-TAC on POD 3 (mean, 5.05 [SD, 3.58] ng/mL vs mean, 2.42 [SD, 2.75] ng/mL, P = .03) and POD 5 (mean, 7.35 [SD, 5.12] ng/mL vs mean, 4.17 [SD, 2.05] ng/mL, P = .04), while no differences were found on PODs 7, 15, and 30.The percentage of patients on POD 3 achieving a trough level higher than 6 ng/mL was higher for LCP-TAC than TAC-PR (40% vs 13%, P = .05). CONCLUSIONS: LCP-TAC after LT is safe and might enhance bioavailability, reducing the amount of drug necessary to achieve therapeutic trough levels compared with TAC-PR.

Gastrointestinal Perforations in Adult Whole-Liver Transplant Patients: Clinical, Radiologic, and Histopathologic Analysis.

BACKGROUND: Gastrointestinal perforation (GIP) is a rare complication after adult liver transplant (LT) associated with high morbidity and mortality. Limited data are available about clinical risk factors and underlying pathogenic mechanisms. METHODS: The retrospective study included all GIP cases from a consecutive cohort of 361 LT recipients during the period 2005-2017. Clinical variables were investigated as potential risk factors for GIP, and radiologic and histopathologic evaluations were undertaken to identify any causative mechanism. RESULTS: A total of 22 patients developed at least 1 episode of GIP (prevalence 6.1%) at a median time of 18.5 [interquartile range, 12.5-28.5] days after LT. The perforations occurred in the small bowel (63.6%), transverse colon (27.3%), right colon (22.7%), left colon (9.1%), and stomach (9.1%). A total of 27.3% of patients developed multiple sites of GIP, and in 31% GIP recurred after curative surgery. The 30-day mortality rate after relaparotomy was 40%. A history of previous abdominal surgery (odds ratio, 2.5) and early post-LT relaparotomy due to other complications (odds ratio, 2.6) were significant risk factors for GIP. No thromboembolic or steno-occlusive complications of any splanchnic vessel were detected at computed tomography scan, while histopathology examination on perforated gastrointestinal segments excluded cytomegalovirus infection, graft-vs-host disease, and inflammatory bowel disease. In all the cases, ischemic necrosis with aspecific microangiopathy and microembolization were the pathologic features detected. CONCLUSIONS: GIP is a severe complication after LT with frequent multiple gastrointestinal involvement and recurrence after curative surgery. The pathologic underlying mechanism is usually microvascular ischemia. Clinical risk factors are history of previous abdominal surgery and early post-LT relaparotomy.