Endovascular Graft Repair for Blunt Traumatic Disruption of the Thoracic Aorta: Experience at a Nonuniversity Hospital

Blunt thoracic aortic injury (BAI) represents the second leading cause of death from blunt trauma. Admission rates for BAI are extremely low because instant fatality occurs in nearly 75 per cent of patients. Management strategies have transitioned from the more invasive immediate thoracotomy to delayed endograft repair with strict hemodynamic management. In this study, we assess outcomes and complications of open versus endograft repair for BAI at a nonuniversity hospital. Retrospective chart review was conducted on 49 patients admitted to a Level I trauma center who incurred BAI from 2004 to 2011. Collected data points included demographics, mortality, complication rates, and intensive care unit and hospital length of stay (LOS). Twenty-one patients underwent open thoracotomy (OPEN), whereas 28 patients were managed with thoracic endovascular aortic repair (TEVAR). The overall 30-day mortality rate was significantly lower comparing TEVAR to OPEN (7.1 vs 50%, P = 0.028); seven deaths occurred in the OPEN group versus two with TEVAR. Overall complications, including mortality, acute respiratory distress syndrome, renal failure, pneumonia, pulmonary embolism, and cardiac arrest, were fewer after TEVAR (32.1 vs 81.0%, P < 0.001) despite similar injury severity. Survivor hospital LOS (26.0 ± 15.3 vs 27.7 ± 18.7 days, P = 0.79), intensive care unit LOS (13.5 ± 10.9 vs 12.7 ± 8.8 days, P = 0.94), and ventilator days (11.4 ± 13.4 vs 16.4 ± 14.5 days, P = 0.25) were similar. Early nonoperative management with TEVAR for BAIs is a feasible and effective management strategy. Improved patient outcomes over traditional open thoracotomy in the presence of similar injury severity can be seen after TEVAR in the nonuniversity hospital setting.

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

BACKGROUND

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.

METHODS

This was a multi-institutional evaluation of patients who underwent MWA between 2003 and 2012. Morbidity (90-day) and mortality were compared between patients who had MWA alone and those who underwent combined resection and MWA (CRA). Mortality and overall survival after CRA were compared with published data on two-stage resections.

RESULTS

Some 201 patients with bilobar colorectal liver metastasis treated with MWA from four high-volume institutions were evaluated (100 MWA alone, 101 CRA). Patients who had MWA alone were older, but the groups were otherwise well matched demographically. The tumour burden was higher in the CRA group (mean number of lesions 3·9 versus 2·2; P = 0·003). Overall (31·7 versus 15·0 per cent; P = 0·006) and high-grade (13·9 versus 5·0 per cent; P = 0·030) complication rates were higher in the CRA group. Median overall survival was slightly shorter in the CRA group (38·4 versus 42·2 months; P = 0·132) but disease-free survival was similar (10·1 versus 9·3 months; P = 0·525). The morbidity and mortality of CRA compared favourably with rates in the existing literature on two-stage resection, and survival data were similar.

CONCLUSION

Single-stage hepatectomy and MWA resulted in survival similar to that following two-stage hepatectomy, with less overall 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.

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

INTRODUCTION

Fibrin 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.

RESULTS

Current 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.

CONCLUSIONS

In 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.

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.

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.

Endovascular graft repair for blunt traumatic disruption of the thoracic aorta: experience at a nonuniversity hospital

Blunt thoracic aortic injury (BAI) represents the second leading cause of death from blunt trauma. Admission rates for BAI are extremely low because instant fatality occurs in nearly 75 per cent of patients. Management strategies have transitioned from the more invasive immediate thoracotomy to delayed endograft repair with strict hemodynamic management. In this study, we assess outcomes and complications of open versus endograft repair for BAI at a nonuniversity hospital. Retrospective chart review was conducted on 49 patients admitted to a Level I trauma center who incurred BAI from 2004 to 2011. Collected data points included demographics, mortality, complication rates, and intensive care unit and hospital length of stay (LOS). Twenty-one patients underwent open thoracotomy (OPEN), whereas 28 patients were managed with thoracic endovascular aortic repair (TEVAR). The overall 30-day mortality rate was significantly lower comparing TEVAR to OPEN (7.1 vs 50%, P = 0.028); seven deaths occurred in the OPEN group versus two with TEVAR. Overall complications, including mortality, acute respiratory distress syndrome, renal failure, pneumonia, pulmonary embolism, and cardiac arrest, were fewer after TEVAR (32.1 vs 81.0%, P < 0.001) despite similar injury severity. Survivor hospital LOS (26.0 ± 15.3 vs 27.7 ± 18.7 days, P = 0.79), intensive care unit LOS (13.5 ± 10.9 vs 12.7 ± 8.8 days, P = 0.94), and ventilator days (11.4 ± 13.4 vs 16.4 ± 14.5 days, P = 0.25) were similar. Early nonoperative management with TEVAR for BAIs is a feasible and effective management strategy. Improved patient outcomes over traditional open thoracotomy in the presence of similar injury severity can be seen after TEVAR in the nonuniversity hospital setting.

Evaluation of ECHO PS Positioning System in a Porcine Model of Simulated Laparoscopic Ventral Hernia Repair

Purpose. Operative efficiency improvements for laparoscopic ventral hernia repair (LVHR) have focused on reducing operative time while maintaining overall repair efficacy. Our objective was to evaluate procedure time and positioning accuracy of an inflatable mesh positioning device (Echo PS Positioning System), as compared to a standard transfascial suture technique, using a porcine model of simulated LVHR. Methods. The study population consisted of seventeen general surgeons (n = 17) that performed simulated LVHR on seventeen (n = 17) female Yorkshire pigs using two implantation techniques: (1) Ventralight ST Mesh + Echo PS Positioning System (Echo PS) and (2) Ventralight ST Mesh + transfascial sutures (TSs). Procedure time and mesh centering accuracy overtop of a simulated surgical defect were evaluated. Results. Echo PS demonstrated a 38.9% reduction in the overall procedure time, as compared to TS. During mesh preparation and positioning, Echo PS demonstrated a 60.5% reduction in procedure time (P < 0.0001). Although a trend toward improved centering accuracy was observed for Echo PS (16.2%), this was not significantly different than TS. Conclusions. Echo PS demonstrated a significant reduction in overall simulated LVHR procedure time, particularly during mesh preparation/positioning. These operative time savings may translate into reduced operating room costs and improved surgeon/operating room efficiency.

Outcomes of a prospective multi-center trial of a second-generation composite mesh for open ventral hernia repair

PURPOSE

Composite mesh prostheses incorporate properties of multiple materials for use in open ventral hernia repair (OVHR). This study examines clinical outcomes in patients who underwent OVHR with a polypropylene/expanded polytetrafluoroethylene (ePTFE) composite graft containing a novel polydioxanone (PDO) absorbable ring to facilitate placement and graft positioning.

METHODS

Data were prospectively collected on consecutive patients undergoing OVHR using a synthetic composite mesh. Seven centers enrolled patients during the study period. All patients underwent a standardized surgical procedure consisting of OVHR with sublay intraperitoneal placement of mesh. Mesh fixation was accomplished with peripheral tacks and transfascial sutures.

RESULTS

One hundred and nineteen patients underwent OVHR with the composite mesh. Average age was 55.8 years; there were 71 (59.7 %) females and 48 (40.3 %) males with mean BMI of 33.5 ± 7.1 kg/m(2). One hundred and two (85.7 %) patients presented with primary ventral hernias. Mean defect size was 13.6 cm(2), and mean mesh size was 113.6 cm(2). Most patients (67 %) were discharged the day of surgery. Twelve patients (10.1 %) experienced complications in the perioperative time period primarily consisting of seroma (4.2 %) and ileus (1.7 %). Two patients required reoperation and mesh removal in the early postoperative period for infection and herniorrhaphy site pain, respectively. There was a decline in pain and movement limitation scores between baseline and 1-year follow-up. Six-month (n = 109) and twelve-month (n = 99) follow-up revealed no hernia recurrences (95 % CI 0-3 %, and 0-4 %, respectively).

CONCLUSIONS

The use of this second-generation composite mesh was associated with no hernia recurrences and a low complication rate after open ventral hernia repair.

Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.

Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.

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.