Erin M. Hanna

Microwave ablation for hepatic malignancies: a multiinstitutional analysis.

Objective:This study hypothesized that tumor size, number of tumors, surgical approach, and tumor histology significantly affected microwave ablation (MWA) success and recurrence-free survival. Background:Although many hepatobiliary centers have adopted MWA, the factors that influence local control are not well described. Methods:Consecutive patients with hepatic malignancy treated by MWA were included from 4 high-volume institutions (2003–2011) and grouped by histology: hepatocellular carcinoma (HCC), colorectal liver metastases, neuroendocrine liver metastases, and other cancers. Independent significance of outcome variables was established with logistic regression and Cox proportional hazards models. Results:Four hundred fifty patients were treated with 473 procedures (139 HCC, 198 colorectal liver metastases, 61 neuroendocrine liver metastases, and 75 other) for a total of 875 tumors. Median follow-up was 18 months. Concurrent hepatectomy was performed in 178 patients (38%), and when performed was associated with greater morbidity. Complete ablation was confirmed for 839 of 865 tumors (97.0%) on follow-up cross-sectional imaging (10 were unevaluable). A surgical approach (open, laparoscopic, or percutaneous) had no significant impact on complication rates, recurrence, or survival. The local recurrence rate was 6.0% overall and was highest for HCC (10.1%, P = 0.045) and percutaneously treated lesions (14.1%, P = 0.014). In adjusted models, tumor size 3 cm or more predicted poorer recurrence-free survival (hazard ratio: 1.60, 95% CI: 1.02–2.50, P = 0.039). Conclusions:In this large data set, patients with 3 cm or more tumors showed a propensity for early recurrence, regardless of histology. Higher rates of local recurrence were noted in HCC patients, which may reflect underlying liver disease. There were no significant differences in morbidity or survival based on the surgical approach; however, local recurrence rates were highest for percutaneously ablated tumors.

Robotic hepatobiliary and pancreatic surgery: lessons learned and predictors for conversion†

The use of surgical robots has slowly gained an increasing presence in the realm of hepatobiliary and pancreatic (HPB) surgery. With additional experience, anecdotal evidence has been useful in guiding patient selection for complex robotic procedures. In the following analysis, we reviewed our case series and looked for predictors of conversion in robotic HPB surgery.

Laparoscopic microwave ablation of human liver tumours using a novel three-dimensional magnetic guidance system

BACKGROUND Accurate antenna placement is essential for effective microwave ablation (MWA) of lesions. Laparoscopic targeting is made particularly challenging in liver tumours by the needles trajectory as it passes through the abdominal wall into the liver. Previous optical three-dimensional guidance systems employing infrared technology have been limited by interference with the line of sight during procedures. OBJECTIVE The aim of this study was to evaluate a newly developed magnetic guidance system for laparoscopic MWA of liver tumours in a pilot study. METHODS Thirteen patients undergoing laparoscopic MWA of liver tumours gave consent to their participation in the study and were enrolled. Lesion targeting was performed using the InnerOptic AIM™ 3-D guidance system to track the real-time position and orientation of the antenna and ultrasound probe. RESULTS A total of 45 ablations were performed on 34 lesions. The median number of lesions per patient was two. The mean ± standard deviation lesion diameter was 18.0 ± 9.2 mm and the mean time to target acquisition was 3.5 min. The first-attempt success rate was 93%. There were no intraoperative or immediate postoperative complications. Over an average follow-up of 7.8 months, one patient was noted to have had an incomplete ablation, seven suffered regional recurrences, and five patients remained disease-free. CONCLUSIONS The AIM™ guidance system is an effective adjunct for laparoscopic ablation. It facilitates a high degree of accuracy and a good first-attempt success rate, and avoids the line of site interference associated with infrared systems.

Fibrin sealants and topical agents in hepatobiliary and pancreatic surgery: a critical appraisal

IntroductionFibrin sealants and topical hemostatic agents have been used extensively in hepatobiliary and pancreatic (HPB) surgery to promote coagulation and clot formation decreasing the need for allogeneic blood transfusion and to act as tissue sealants, ideally preventing biliary, enteric, and pancreatic leaks.ResultsCurrent literature has demonstrated some favorable outcomes using many different products for application in the field of HPB surgery. However, critical findings exist demonstrating lack of reproducible efficacy or benefit. In all, many clinical trials have demonstrated effectiveness of fibrin sealants and other agents at reducing the need for intraoperative and postoperative blood transfusion. Ability to effectively seal tissues providing biliostatic effect or preventing postoperative fistula formation remains debated as definitive evidence is lacking.ConclusionsIn the following invited review, we discuss current literature describing the use of topical agents and fibrin sealants in liver and pancreas surgery. We summarize major contemporary clinical trials and their findings regarding the use of these agents in HPB surgery and provide evidence from the preclinical literature as to the translation of these products into the clinical arena.

Adrenocortical Carcinoma with Intracaval Extension to the Right Atrium: Resection on Cardiopulmonary Bypass

Case PresentationA 28-year-old woman presented with dyspnea on exertion and elevated testosterone level. A 21 × 19 cm right adrenal mass was found invading the liver and inferior vena cava (IVC); tumor thrombus extended to the right atrium on transthoracic echocardiogram.Operative ProcedureMedian sternotomy and extended right subcostal incisions were made. Inferior surface of liver was mobilized and vessels to the tumor divided and packed. The IVC was isolated and cardiopulmonary bypass initiated. Tumor was excised from IVC and tumor thrombus extracted. After partial IVC wall resection, the venotomy was closed. The right atrium was explored for remaining thrombus. Segment 7 of the liver was resected with division of right hepatic vein. The patient was removed from bypass, and the cut surface of liver was reinforced with chromic sutures. Intraoperative ultrasound demonstrated no remaining tumor thrombus. Provisional closure was achieved with wound vac, and the next day, the patient’s wound was closed primarily.OutcomeOn postoperative day 3, the patient was extubated; she was discharged on day 12. Pathology revealed well-differentiated adenocarcinoma weighing 2.3 kg with negative surgical margins. Two months after surgery, she received radiation for suspected lumbar vertebral metastasis and initiated mitotane therapy. Follow-up surveillance scans showed no evidence of disease.DiscussionAdrenocortical carcinoma is a rare malignancy presenting frequently in advanced stage with poor prognosis. Chemotherapy is often only moderately effective, while complete surgical resection is potentially curative. In this patient, excellent short-term outcome was achieved through radical surgical resection. We continue to monitor her closely for evidence of recurrence.

Single‐stage resection and microwave ablation for bilobar colorectal liver metastases

Patients undergoing liver resection combined with microwave ablation (MWA) for bilobar colorectal metastasis may have similar overall survival to patients who undergo two‐stage hepatectomy, but with less morbidity.

Optimal Ablation Volumes Are Achieved at Submaximal Power Settings in a 2.45-GHz Microwave Ablation System

Introduction. Local ablative therapies, including microwave ablation (MWA), are common treatment modalities for in situ tumor destruction. Currently, 2.45-GHz ablation systems are gaining prominence because of the shorter application times required. The aims of this study were to determine optimal power and time to ablation volume (AbV) ratios for a new 1.8-mm–2.45-GHz antenna using ex vivo tissue models. Methods. The 1.8-mm–2.45-GHz Accu2i MWA system was employed to perform ablations in bovine liver, porcine muscle, and porcine kidney ex vivo. Whole tissues were prewarmed (35°C) and multiple ablations performed at power settings of 60 to 180 W for 2- to 6-minute time intervals. Postablation, tissues were dissected, AbVs calculated, and correlations to power and time settings made. Results. Significant increases in AbV were measured between each of the time points for a constant power setting in all 3 tissues. Increasing power settings led to significant increases in AbV at power settings ≤140 W. However, no significant increase in AbV was obtained at power settings >140 W. Conclusions. Optimal efficiency for MWA using a new 1.8-mm–2.45-GHz system is achieved at settings of ≤140 W for 6 minutes in a range of ex vivo tissue and no additional benefit occurs by increasing the power setting to 180 W in these tissues.

Comparison of culture and molecular techniques for microbial community characterization in infected necrotizing pancreatitis

BACKGROUND Infected necrotizing pancreatitis is associated with significant morbidity and mortality. Peripancreatic fluid cultures may fail to identify all the infecting organisms. The aim of this study was to compare the bacterial biome of peripancreatic fluid from infected necrotizing pancreatitis patients using 16S ribosomal RNA (rRNA) DNA deep sequencing and quantitative polymerase chain reaction (qPCR) targeting the 16S rRNA gene versus standard laboratory culture. MATERIALS AND METHODS Peripancreatic fluid was collected during operative or radiologic intervention and samples sent for culture. In parallel, microbial DNA was extracted, qPCR targeting the 16S rRNA gene and 16S rRNA PCR amplification followed by Illumina deep sequencing were performed. RESULTS Using culture techniques, the bacterial strains most frequently identified were gram-negative rods (Escherichia coli, Klebsiella pneumoniae) and Enterococcus. Samples in which culture results were negative had copy numbers of the 16S rRNA gene close to background in qPCR analysis. For samples with high bacterial load, sequencing results were in some cases in good agreement with culture data, whereas in others there were disagreements, likely due to differences in taxonomic classification, cultivability, and differing susceptibility to background contamination. Sequencing results appeared generally unreliable in cases of negative culture where little microbial DNA was input into qPCR sequencing reactions. CONCLUSIONS Both sequencing and culture data display their own sources of bias and potential error. Consideration of data from multiple techniques will yield a more accurate view of bacterial infections than can be achieved by any single technique.

Altered lysophosphatidic acid (LPA) receptor expression during hepatic regeneration in a mouse model of partial hepatectomy.

BACKGROUND Hepatic regeneration requires coordinated signal transduction for efficient restoration of functional liver mass. This study sought to determine changes in lysophosphatidic acid (LPA) and LPA receptor (LPAR) 1-6 expression in regenerating liver following two-thirds partial hepatectomy (PHx). METHODS Liver tissue and blood were collected from male C57BL/6 mice following PHx. Circulating LPA was measured by enzyme-linked immunosorbent assay (ELISA) and hepatic LPAR mRNA and protein expression were determined. RESULTS Circulating LPA increased 72 h after PHx and remained significantly elevated for up to 7 days post-PHx. Analysis of LPAR expression after PHx demonstrated significant increases in LPAR1, LPAR3 and LPAR6 mRNA and protein in a time-dependent manner for up to 7 days post-PHx. Conversely, LPAR2, LPAR4 and LPAR5 mRNA were barely detected in normal liver and did not significantly change after PHx. Changes in LPAR1 expression were confined to non-parenchymal cells following PHx. CONCLUSIONS Liver regeneration following PHx is associated with significant changes in circulating LPA and hepatic LPAR1, LPAR3 and LPAR6 expression in a time- and cell-dependent manner. Furthermore, changes in LPA-LPAR post-PHx occur after the first round of hepatocyte division is complete.

Minimally Invasive Esophagectomy in the Community Hospital Setting

We report our initial experience with minimally-invasive esophagectomy in 32 patients at Carolinas Medical Center, a community academic medical center. Indications for surgery were adenocarcinoma in 27, squamous cell carcinoma in 3, and benign stricture in 2. Transthoracic Ivor-Lewis esophagectomy with laparoscopy and thoracoscopy was performed in 28, a 3-stage esophagectomy in 3, and transhaital esophagectomy in 1. There was no operative mortality and median hospital stay was 10.5 days for patients treated with minimally invasive esophagectomy. This compares with an operative mortality of 8.9% and median hospital stay of 17 days for open esophagectomy in our institution.