Liver resection for hepatolithiasis: A multicenter experience in Latin America.

BACKGROUND: Hepatolithiasis is a prevalent disease in Asia but rare in Western countries. An increasing number of cases have been reported in Latin America. Liver resection has been proposed as a definitive treatment for complete stone clearance. The aim of this study was to evaluate the postoperative outcomes of liver resection for the treatment of hepatolithiasis in 2 large hepatobiliary reference centers from South America. METHODS: We conducted a retrospective descriptive analysis from patients with hepatolithiasis who underwent liver resection between November 1986 and December 2018, in 2 Latin-American centers in Chile and Brazil. RESULTS: One hundred forty-nine patients underwent liver resection for hepatolithiasis (72 in Chile, 77 in Brazil). The mean age was 49 years and most patients were female (62.4%). Hepatolithiasis was localized in the left lobe (61.7%), right lobe (24.2%), and bilateral lobe (14.1%). Bilateral lithiasis was associated with higher incidence of preoperative and postoperative cholangitis (81% vs 46.9% and 28.6% vs 6.1%) and need for hepaticojejunostomy (52.4%). In total, 38.9% of patients underwent major hepatectomy and 14.1% were laparoscopic. The postoperative stone clearance was 100%. The 30-day morbidity and mortality rates were 30.9% and 0.7%, respectively. Cholangiocarcinoma was seen in 2 specimens, and no postoperative malignancy were seen after a median follow-up of 38 months. Fourteen patients (9.4%) had intrahepatic stones recurrence. CONCLUSIONS: Liver resection is an effective and definitive treatment for patients with hepatolithiasis. Bilateral hepatolithiasis was associated with perioperative cholangitis, the need for hepaticojejunostomy, and recurrent disease. Resection presents a high rate of biliary tree stone clearance and excellent long-term results, with low recurrence rates and low risk of malignancy.

Renal outcomes following left renal vein harvest for venous reconstruction during pancreas and liver surgery.

BACKGROUND: The left renal vein (LRV) may be used for venous reconstruction during hepato-pancreato-biliary (HPB) surgery, although concerns exist about compromising renal function. This study aimed to determine renal outcomes following LRV harvest during HPB resections. METHODS: Circumferential PV/SMV resections from 2008 to 2014 were included within two groups (LRV harvest, Control). Absolute and change in Creatinine (Cr) and estimated GFR (eGFR), and rates of acute kidney injury (AKI) and chronic kidney disease (CKD), were compared. Multivariate logistic regression analyses were performed. RESULTS: 76 patients were included (LRV n = 17, Control n = 59). Median Cr and eGFR did not change within groups, although change in eGFR differed between groups at postoperative day (POD) 3 (-4.3 vs. 12.8, p = 0.0035) and 7 (-1.8 vs. 12.4, p = 0.0074). AKI occurred more frequently in the LRV group at POD1 (5/17 vs. 4/59, p = 0.023) and POD3 (5/17 vs. 3/59, p = 0012), with no difference in CKD between groups (2/11 vs. 5/33 at 3 months, p = 0.99). LRV harvest was an independent risk factor for AKI at POD1 and POD3, but not thereafter. CONCLUSIONS: Patients who undergo LRV harvest experience a higher rate of AKI in the first three post-operative days. LRV harvest during pancreas resection does not impact on long-term renal function.

Liver Transplantation Without Venovenous Bypass: Does Surgical Approach Matter?

BACKGROUND: The use of venovenous bypass in liver transplantation has declined over time. Few studies have examined the impact of surgical approach in cases performed exclusively without venovenous bypass. We hypothesized that advances in liver transplant anesthesia and perioperative care have minimized the importance of surgical approach in the modern era. METHODS: Deceased donor liver transplants at the University of Toronto from 2000 to 2015 were reviewed, all performed without venovenous bypass. First, an unadjusted analysis was performed comparing perioperative outcomes and graft/patient survival for 3 different liver transplant techniques (caval interposition, piggyback, side-to-side cavo-cavostomy). Second, a propensity-matched analysis was performed comparing caval interposition to caval-preserving techniques. RESULTS: One thousand two hundred thirty-three liver transplants were included in the study. On unadjusted analysis, blood loss, transfusion requirement, postoperative complications, and graft/patient survival were equivalent for the 3 different techniques. To account for possible confounding patient variables, propensity matching was performed. Analysis of the propensity-matched cohorts also demonstrated similar outcomes for caval interposition versus caval-preserving approaches. CONCLUSIONS: In the modern era at centers with a multidisciplinary team, the importance of specific liver transplant technique is minimized. Full or partial cross-clamping of the inferior vena cava is feasible without the use of venovenous bypass.

The Volume-outcome Relationship in Deceased Donor Kidney Transplantation and Implications for Regionalization.

OBJECTIVE: The aim of this study was to investigate the volume-outcome relationship in kidney transplantation by examining graft and patient outcomes using standardized risk adjustment (observed-to-expected outcomes). A secondary objective was to examine the geographic proximity of low, medium, and high-volume kidney transplant centers in the United States. SUMMARY OF BACKGROUND DATA: The significant survival benefit of kidney transplantation in the context of a severe shortage of donor organs mandates strategies to optimize outcomes. Unlike for other solid organ transplants, the relationship between surgical volume and kidney transplant outcomes has not been clearly established. METHODS: The Scientific Registry of Transplant Recipients was used to examine national outcomes for adults undergoing deceased donor kidney transplantation from January 1, 1999 to December 31, 2013 (15-year study period). Observed-to-expected rates of graft loss and patient death were compared for low, medium, and high-volume centers. The geographic proximity of low-volume centers to higher volume centers was determined to assess the impact of regionalization on patient travel burden. RESULTS: A total of 206,179 procedures were analyzed. Compared with low-volume centers, high-volume centers had significantly lower observed-to-expected rates of 1-month graft loss (0.93 vs 1.18, P<0.001), 1-year graft loss (0.97 vs 1.12, P<0.001), 1-month patient death (0.90 vs 1.29, P=0.005), and 1-year patient death (0.95 vs 1.15, P=0.001). Low-volume centers were frequently in close proximity to higher volume centers, with a median distance of 7 miles (interquartile range: 2 to 75). CONCLUSIONS: A robust volume-outcome relationship was observed for deceased donor kidney transplantation, and low-volume centers are frequently in close proximity to higher volume centers. Increased regionalization could improve outcomes, but should be considered carefully in light of the potential negative impact on transplant volume and access to care.

Pancreas Transplantation With Portal-Enteric Drainage for Patients With Endocrine and Exocrine Insufficiency From Extensive Pancreatic Resection.

Although the primary indication for pancreas transplantation is type I diabetes, a small number of patients requires pancreas transplantation to manage combined endocrine and exocrine insufficiency that develops after extensive native pancreatic resection. The objective of this case report was to describe the operative and clinical course in 3 such patients and present an alternative technical approach.

Early Intervention With Live Donor Liver Transplantation Reduces Resource Utilization in NASH: The Toronto Experience.

BACKGROUND: In parallel with the obesity epidemic, liver transplantation for nonalcoholic steatohepatitis (NASH) is increasing dramatically in North America. Although survival outcomes are similar to other etiologies, liver transplantation in the NASH population has been associated with significantly increased resource utilization. We sought to compare outcomes between live donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) at a high volume North American transplant center, with a particular focus on resource utilization. METHODS: The study population consists of primary liver transplants performed for NASH at Toronto General Hospital from 2000 to 2014. Recipient characteristics, perioperative outcomes, graft and patient survivals, and resource utilization were compared for LDLT versus DDLT. RESULTS: A total of 176 patients were included in the study (48 LDLT vs 128 DDLT). LDLT recipients had a lower model for end-stage liver disease score and were less frequently hospitalized prior to transplant. Estimated blood loss and early markers of graft injury were lower for LDLT. LDLT recipients had a significantly shorter hospitalization (intensive care unit, postoperative, and total hospitalization). CONCLUSIONS: LDLT for NASH facilitates transplantation of patients at a less severe stage of disease, which appears to promote a faster postoperative recovery with less resource utilization.

CT volumetry is superior to nuclear renography for prediction of residual kidney function in living donors.

Living kidney donor evaluation commonly includes nuclear renography to assess split kidney function and computed tomography (CT) scan to evaluate anatomy. To streamline donor workup and minimize exposure to radioisotopes, we sought to assess the feasibility of using proportional kidney volume from CT volumetry in lieu of nuclear renography. We examined the correlation between techniques and assessed their ability to predict residual postoperative kidney function following live donor nephrectomy. In a cohort of 224 live kidney donors, we compared proportional kidney volume derived by CT volumetry with split kidney function derived from nuclear renography and found only modest correlation (left kidney R(2) =26.2%, right kidney R(2) =26.7%). In a subset of 88 live kidney donors with serum creatinine measured 6 months postoperatively, we compared observed estimated glomerular filtration rate (eGFR) at 6 months with predicted eGFR from preoperative imaging. Compared to nuclear renography, CT volumetry more closely approximated actual observed postoperative eGFR for Chronic Kidney Disease Epidemiology Collaboration (J-test: P=.02, Cox-Pesaran test: P=.01) and Mayo formulas (J-test: P=.004, Cox-Pesaran test: P<.001). These observations support the use of CT volumetry for estimation of split kidney function in healthy individuals with normal kidney function and morphology.

Technique and outcomes of robot-assisted median arcuate ligament release for celiac artery compression syndrome.

OBJECTIVE: Celiac artery compression by the median arcuate ligament (MAL) is a potential cause of postprandial abdominal pain and weight loss that overlaps with other common syndromes. Robotic technology may alter the current paradigm for surgical intervention. Open MAL release is often performed with concurrent bypass for celiac stenosis due to the morbidity of reintervention, whereas the laparoscopic approach is associated with high rates of conversion to open due to bleeding. We hypothesized that a robot-assisted technique might minimize conversion events to open, decrease perioperative morbidity, and defer consideration of vascular bypass at the initial operative setting. METHODS: We retrospectively analyzed patients treated for MAL syndrome by a multidisciplinary team at a tertiary medical center between September 2012 and December 2013. Diagnosis was based on symptom profile and peak systolic velocity (PSV) >200 cm/s during celiac artery duplex ultrasound imaging. All patients underwent robot-assisted MAL release with simultaneous circumferential neurolysis of the celiac plexus. Postoperative celiac duplex and symptom profiles were reassessed longitudinally to monitor outcomes. RESULTS: Nine patients (67% women) were evaluated for postprandial pain (100%) and weight loss (100%). All patients had celiac stenosis by mesenteric duplex ultrasound imaging (median PSV, 342; range, 238-637 cm/s), and cross-sectional imaging indicated a fishhook deformity in five (56%). Robot-assisted MAL release was completed successfully in all nine patients (100%) using a standardized surgical technique. Estimated blood loss was <50 mL, with a median hospital stay of 2 days (range, 2-3 days). No postoperative complications of grade ≥3, readmissions or reoperations were observed. All patients (100%) improved symptomatically at the 25-week median follow-up. Three patients experienced complete resolution on postoperative celiac duplex ultrasound imaging, and six patients showed an improved but persistent stenosis (PSV >200 cm/s) compared with preoperative velocities (P < .05 by Wilcoxon signed rank). No patients required additional treatment. CONCLUSIONS: Robot-assisted MAL release can be performed safely and effectively with avoidance of conversion events and minimal morbidity. Potential factors contributing to success are patient selection by a multidisciplinary team and replication of the open surgical technique by means of robot-assisted dexterity and visualization. The need for delayed reintervention for persistently symptomatic celiac stenosis is uncertain.

Tob1 is a constitutively expressed repressor of liver regeneration.

How proliferative and inhibitory signals integrate to control liver regeneration remains poorly understood. A screen for antiproliferative factors repressed after liver injury identified transducer of ErbB2.1 (Tob1), a member of the PC3/BTG1 family of mito-inhibitory molecules as a target for further evaluation. Tob1 protein decreases after 2/3 hepatectomy in mice secondary to posttranscriptional mechanisms. Deletion of Tob1 increases hepatocyte proliferation and accelerates restoration of liver mass after hepatectomy. Down-regulation of Tob1 is required for normal liver regeneration, and Tob1 controls hepatocyte proliferation in a dose-dependent fashion. Tob1 associates directly with both Caf1 and cyclin-dependent kinase (Cdk) 1 and modulates Cdk1 kinase activity. In addition, Tob1 has significant effects on the transcription of critical cell cycle components, including E2F target genes and genes involved in p53 signaling. We provide direct evidence that levels of an inhibitory factor control the rate of liver regeneration, and we identify Tob1 as a crucial check point molecule that modulates the expression and activity of cell cycle proteins.

Roux limb volvulus after pancreas transplantation: an unusual cause of pancreatic graft loss.

Pancreas transplantation with enteric drainage avoids the long-term urological complications of bladder drainage. Increasing use of this technique raises the possibility of complications from the enteric reconstruction. This report describes a patient five yr after left-sided pancreas transplant with Roux-en-Y enteric drainage, presenting with abdominal pain, leukocytosis and radiological evidence of bowel obstruction. Exploration revealed a volvulus of the Roux limb as it passed through the mesocolon, with necrosis of the allograft duodenum and marked congestion of the pancreas. This is the first report of pancreas graft loss due to this entity, which should be recognized as an unusual cause of abdominal pain after pancreas transplantation. Potential bowel complications related to the sigmoid mesentery in left-sided pancreas transplantation are additional reasons for right-sided placement of the pancreas allograft.