Robert M. Cannon

Safety and early efficacy of irreversible electroporation for hepatic tumors in proximity to vital structures

Irreversible electroporation (IRE) has shown promise for ablation of lesions in proximity to vital structures in the preclinical setting. This study aims to evaluate the safety and efficacy of IRE for hepatic tumors in the clinical setting.

Management of Benign Hepatic Tumors

Advances in imaging techniques will dramatically decrease the number of undiagnosed tumors. New molecular techniques should allow the identification of pathologic factors that are predictive of complicated forms. Surgery should be limited to symptomatic benign tumors or those who have a risk for complication (hemorrhage, rupture, or degeneration). When surgery is indicated, patients with benign disease are the best candidates for laparoscopy.

Laparoscopic Liver Resection: An Examination of Our First 300 Patients

BACKGROUND Laparoscopic liver resection is a procedure in evolution. In the last decade it has evolved from a novel procedure to a standard part of the hepatic surgeons armamentarium. Few data exist on the development of a laparoscopic resection program. STUDY DESIGN With IRB approval, a retrospective review of 300 consecutive laparoscopic liver resections was undertaken. To determine changing results and patterns of practice, the cohort was divided into 3 consecutive groups of 100 patients. Patient demographics, indications for operation, operative factors, and in-hospital outcomes were examined. Continuous variables were analyzed with the Kruskal-Wallis test; continuous variables were compared with Fishers exact test. Univariate and multivariate analyses of major complications (≥grade 3) were performed using logistic regression. RESULTS Of the 300 patients, 173 (61.6%) were female, with a median age of 54 years. There were 133 (44.3%) major resections. The median number of segments resected increased (3 vs 2, p = 0.015), as did the percentage of repeat hepatectomies (13.0% vs 2.0%, p = 0.001). At the same time, median operative time decreased (2.25 vs 3.0 hours, p < 0.001).and estimated blood loss was similar (150 mL vs 150 mL, p = 0.635). Morbidity was similar (11% vs 14%, p = 0.300), as was mortality (1% vs 3%, p = 0.625). CONCLUSIONS Laparoscopic liver resection has evolved from a novel procedure to a vital technique in liver surgery. Our group has demonstrated the ability over time to perform more difficult resections with similar morbidity and decreased operative length.

A review of the United States experience with combined heart-liver transplantation

Since first described by Starzl, combined heart and liver transplantation (CHLT) has been a relatively rare event, although utilization has increased in the past decade. This study was undertaken to review the United States experience with this procedure; UNOS data on CHLT was reviewed. CHLT was compared with liver transplantation alone and heart transplantation alone in terms of acute rejection within 12 months, graft survival, and patient survival. Survival was calculated according to Kaplan–Meier and Cox proportional hazards. Continuous variables were compared using Student’s t‐test and categorical variables with chi‐squared. Between 1987 and 2010, there were 97 reported cases of CHLT in the United States. Amyloidosis was the most common indication for both heart (n = 26, 26.8%) and liver (n = 27, 27.8%) transplantation in this cohort. Liver graft survival in the CHLT cohort at 1, 5, and 10 years was 83.4%, 72.8%, and 71.0%, whereas survival of the cardiac allograft was 83.5%, 73.2%, and 71.5%. This was similar to graft survival in liver alone transplantation (79.4%, 71.0%, 65.1%; P = 0.894) and heart transplantation alone (82.6%, 71.9%, 63.2%; P = 0.341). CHLT is a safe and effective procedure, with graft survival rates similar to isolated heart and isolated liver transplantation.

Is Laparoscopic Repeat Hepatectomy Feasible? A Tri-institutional Analysis

BACKGROUND A laparoscopic approach has not been advocated for repeat hepatectomy on a large scale. This report analyzes the experience of 3 institutions pioneering laparoscopic repeat liver resection (LRLR). The aim of this study was to evaluate the feasibility, safety, oncologic integrity, and outcomes of LRLR. STUDY DESIGN All patients undergoing LRLR were identified. Since 1997, 76 LRLRs have been attempted. Operative indications were metastasis (n = 63), hepatocellular carcinoma (n = 3), and benign tumors (n = 10). All patients had 1 or more earlier liver resections (28 open, 44 laparoscopic), including 16 major resections (en bloc removal of 3 or more Couinaud segments). RESULTS Eight conversions (11%) to open resections (n = 7) or radiofrequency ablation (n = 1) were required due to technical difficulties or hemorrhage. LRLRs included 49 wedge or segmental resections and 19 major hepatectomies. Median blood loss and operative time were 300 mL and 180 minutes. Patients with previous open liver resection (group B) experienced more intraoperative blood loss and transfusion requirements than those with earlier laparoscopic resections (group A) (p = 0.02; p = 0.01, respectively). R0 resection was achieved in 58 of 64 (91%) patients with malignant tumor. The incidence of postoperative complications and duration of hospital stay were not statistically different between the 2 groups. Bile leakages developed in 5 (6.6%) patients, including 1 requiring reoperation. There was no perioperative death. Median tumor size was 25 mm (range 5 to 125 mm) and the median number of tumors was 2 (range 1 to 7). Median follow-up was 23.5 months (range 0 to 86 months). There was no port-site metastasis. The 3- and 5-year actuarial survivals for patients with colorectal metastases were 83% and 55%, respectively. CONCLUSIONS Laparoscopic repeat hepatic resections can be performed safely and with good results, particularly in patients with earlier laparoscopic resections.

The impact of recipient obesity on outcomes after renal transplantation.

Background:The benefit of renal transplantation in obese patients is controversial, with many centers setting upper limits on body mass index (BMI) in consideration for listing patients for transplant. This study was undertaken to determine the effect of recipient obesity on delayed graft function (DGF) and graft survival after renal transplantation. Methods:Retrospective review of all renal transplant recipients in the United Network for Organ Sharing database from January 1, 2004, through December 31, 2009, was performed. Primary endpoints were DGF and non–death-censored graft survival. Comparisons were made on the basis of the following weight classes: nonobese (BMI < 30), class I obese (30 ⩽ BMI < 35), class II obese (35 ⩽ BMI < 40), and class III obese (BMI ≥ 40). Results:Multivariable logistic regression indicated a significantly increased risk for DGF in obese patients. The odds ratios for DGF compared with nonobese patients were 1.34 [95% confidence interval (CI) 1.27–1.42; P < 0.001], 1.68 (95% CI 1.56–1.82; P < 0.001), and 2.68 (95% CI 2.34–3.07; P < 0.001) for the class I obese, class II obese, and class III obese groups, respectively. Class I obesity was not a significant risk for non–death-censored graft failure [hazard ratio (HR) 1.00, 95% CI 0.95–1.05; P = 0.901] compared with nonobese patients. Patients in the class II obese (HR 1.15, 95% CI 1.07–1.24; P < 0.001) and class III obese (HR 1.26, 95% CI 1.11–1.43; P < 0.001) groups were at a significantly increased risk for graft failure than their nonobese counterparts. Conclusions:Obese patients in all weight classes are at an increased risk for DGF after renal transplantation, although differences in non–death-censored graft survival are such that transplantation should not be denied on the basis of BMI criteria alone.

Surgical resection for hilar cholangiocarcinoma: experience improves resectability

OBJECTIVES   In hilar cholangiocarcinoma, resection provides the only opportunity for longterm survival. A US experience of hilar cholangiocarcinoma was examined to determine the effect of clinical experience on negative margin (R0) resection rates. METHODS   We conducted a retrospective analysis of 110 consecutive hilar cholangiocarcinoma patients presenting over an 18-year period. Analyses were performed using chi-squared, Wilcoxon rank sum and Kaplan-Meier methods, and multivariable Cox and logistic regression modelling. RESULTS   Of the 110 patients in the cohort, 59.1% were male and 90.9% were White. The median patient age was 64 years. A total of 59 (53.6%) patients underwent resection; 37 of these demonstrated R0. The 30-day mortality rate was 5.1%; the complication rate was 39.0%. The rate of resectability increased over time (36.4% vs. 70.9%; P= 0.001), as did the percentage of R0 resections (10.9% vs. 56.5%; P < 0.001). Of the 59 patients who underwent resection, 23 (39.0%) experienced recurrence. Multivariable Cox regression analysis identified resection margins [hazard ratio (HR) = 4.124 for positive vs. negative; P= 0.002] and type of operation (HR = 5.075 for exploration vs. resection; P= 0.001) as significant to survival. CONCLUSIONS   Although R0 resection can be achieved in only a minority of patients, these patients have a reasonable chance of longterm survival. The last decade has seen a significant rise in rates of resectability of Klatskins tumour at specialty centres.

Safety and efficacy of hepatectomy for colorectal metastases in the elderly.

The aim of this study was to determine the safety and efficacy of hepatic metastasectomy in elderly patients with colorectal liver metastases (CLM).

Recipient obesity and outcomes after kidney transplantation: a systematic review and meta-analysis

BACKGROUND The prevalence of obesity is increasing globally and is associated with chronic kidney disease and premature mortality. However, the impact of recipient obesity on kidney transplant outcomes remains unclear. This study aimed to investigate the association between recipient obesity and mortality, death-censored graft loss and delayed graft function (DGF) following kidney transplantation. METHODS A systematic review and meta-analysis was conducted using Medline, Embase and the Cochrane Library. Observational studies or randomized controlled trials investigating the association between recipient obesity at transplantation and mortality, death-censored graft loss and DGF were included. Obesity was defined as a body mass index (BMI) of ≥30 kg/m(2). Obese recipients were compared with those with a normal BMI (18.5-24.9 kg/m(2)). Pooled estimates of hazard ratios (HRs) for patient mortality or death-censored graft loss and odds ratios (ORs) for DGF were calculated. RESULTS Seventeen studies including 138 081 patients were analysed. After adjustment, there was no significant difference in mortality risk in obese recipients [HR = 1.24, 95% confidence interval (CI) = 0.90-1.70, studies = 5, n = 83 416]. However, obesity was associated with an increased risk of death-censored graft loss (HR = 1.06, 95% CI = 1.01-1.12, studies = 5, n = 83 416) and an increased likelihood of DGF (OR = 1.68, 95% CI = 1.39-2.03, studies = 4, n = 28 847). CONCLUSIONS Despite having a much higher likelihood of DGF, obese transplant recipients have only a slightly increased risk of graft loss and experience similar survival to recipients with normal BMI.

Assessment of Chemotherapy Response in Colorectal Liver Metastases in Patients Undergoing Hepatic Resection and the Correlation to Pathologic Residual Viable Tumor

BACKGROUND The Response Evaluation Criteria in Solid Tumors (RECIST), which evaluates maximum tumor diameter only, is commonly used to determine response to chemotherapy in patients with colorectal liver metastases. Limitations of RECIST include its inability to assess the changes in tumor enhancement. The aim of this study was to assess the correlation of these criteria as well as the modified RECIST (mRECIST) with pathologic tumor response. A novel semi-automated volumetric assessment of tumor size was also investigated. STUDY DESIGN A review of a 1,948-patient prospective hepatic database to assess response and pathologic criteria was performed. Patients undergoing preoperative chemotherapy before hepatic resection for colorectal liver metastases were reviewed. Radiographic responses according to RECIST and mRECIST were determined. The percentage of viable tumor cells compared with the total tumor area was determined from the pathologic specimens. RESULTS We identified 38 patients with adequate imaging who had undergone anatomic hepatic resection and full pathologic evaluation. The percentages of residual viable tumor in the resected specimens were significantly different across RECIST categories (p = 0.045), but not mRECIST (p = 0.305). For mRECIST, there were improved and significant linear trends for residual viable tumor, necrosis, and necrosis + fibrosis when compared with RECIST (p = 0.056). Neither RECIST nor mRECIST responses were predictive of residual viable tumor burden in regression analyses. A novel semi-automated volumetric assessment of tumor size correlated well with pathologic tumor size. CONCLUSIONS Neither RECIST nor mRECIST were predictive of residual viable burden, although the linear trend for mRECIST and residual necrosis + fibrosis compared favorably with RECIST. Continued evaluation for tumor enhancement and standardization of tumor size remain a critical unmet need in patients with solid organ disease.