Developing and validating a center-specific preoperative prediction calculator for risk of pancreaticoduodenectomy

BACKGROUND

The American College of Surgeons (ACS) Surgical Risk Calculator predicts postoperative risk based on preoperative variables. The ACS model was compared to an institution-specific risk calculator for pancreaticoduodenectomy (PD).

METHODS

Observed outcomes were compared with those predicted by the ACS and institutional models. Receiver operating characteristic (ROC) analysis evaluated the models' predictive ability. Institutional models were evaluated with retrospective and prospective internal validation.

RESULTS

Brier scores indicate equivalent aggregate predictive ability. ROC values for the institutional model (ROC: 0.675-0.881, P < 0.01) indicate superior individual event occurrence prediction (ACS ROC: 0.404-0.749, P < 0.01-0.860). Institutional models' accuracy was upheld in retrospective (ROC: 0.765-0.912) and prospective (ROC: 0.882-0.974) internal validation.

CONCLUSIONS

Identifying higher-risk patients allows for individualized care. While ACS and institutional models accurately predict average complication occurrence, the institutional models are superior at predicting individualized outcomes. Predictive metrics specific to PD center volume may more accurately predict outcomes.

A novel 3-dimensional electromagnetic guidance system increases intraoperative microwave antenna placement accuracy

BACKGROUND

Failure to locate lesions and accurately place microwave antennas can lead to incomplete tumor ablation. The Emprint™ SX Ablation Platform employs real-time 3D-electromagnetic spatial antenna tracking to generate intraoperative laparoscopic antenna guidance. We sought to determine whether Emprint™ SX affected time/accuracy of antenna-placement in a laparoscopic training model.

METHODS

Targets (7-10 mm) were set in agar within a laparoscopic training device. Novices (no surgical experience), intermediates (surgical residents), and experts (HPB-surgeons) were asked to locate and hit targets using a MWA antenna (10-ultrasound only, 10-Emprint™ SX). Time to locate target, number of attempts to hit the target, first-time hit rate, and time from initiating antenna advance to hitting the target were measured.

RESULTS

Participants located 100% of targets using ultrasound, with experts taking significantly less time than novices and intermediates. Using ultrasound only, successful hit-rates were 70% for novices and 90% for intermediates and experts. Using Emprint™ SX, successful hit rates for all 3-groups were 100%, with significantly increased first-time hit-rates and reduced time required to hit targets compared to ultrasound only.

DISCUSSION

Emprint™ SX significantly improved accuracy and speed of antenna-placement independent of experience, and was particularly beneficial for novice users.

Robotic longitudinal pancreaticojejunostomy for chronic pancreatitis: Comparison of clinical outcomes and cost to the open approach

BACKGROUND

This study compares clinical and cost outcomes of robot-assisted laparoscopic (RAL) and open longitudinal pancreaticojejunostomy (LPJ) for chronic pancreatitis.

METHODS

Clinical and cost data were retrospectively compared between open and RAL LPJ performed at a single center from 2008-2015.

RESULTS

Twenty-six patients underwent LPJ: 19 open and 7 RAL. Two robot-assisted cases converted to open were included in the open group for analysis. Patients undergoing RAL LPJ had less intraoperative blood loss, a shorter surgical length of stay, and lower medication costs. Operation supply cost was higher in the RAL group. No difference in hospitalization cost was found.

CONCLUSIONS

Versus the open approach, RAL LPJ performed for chronic pancreatitis shortens hospitalization and reduces medication costs; hospitalization costs are equivalent. A higher operative cost for RAL LPJ is mitigated by a shorter hospitalization. Decreased morbidity and healthcare resource economy support use of the robotic approach for LPJ when appropriate.

Operative microwave ablation for hepatocellular carcinoma: a single center retrospective review of 219 patients

BACKGROUND

Microwave ablation (MWA) of hepatocellular carcinoma (HCC) offers local regional treatment that can be safely and effectively performed, even in patients with advanced liver disease. We update results from our group's previous analysis of operative MWA for HCC.

METHODS

Retrospective review was performed of all patients who underwent operative MWA for HCC from 2007-2014. Patient demographics, operative characteristics and complications were recorded. Follow up imaging was reviewed to determine rates of complete ablation, local, regional and metastatic recurrence.

RESULTS

Two hundred and nineteen patients were included with a total of 340 tumors treated with operative MWA. Median tumor size was 3.2 cm (range, 1-6 cm). Cirrhosis was present in 89.5% of patients, 60.7% had hepatitis C, and 8.2% had hepatitis B. Thirty-five point nine percent were Child-Pugh class B/C. Ninety-six point eight percent of MWA procedures were performed laparoscopically. Four deaths occurred within 30 days (1.8%). Clavien-Dindo grade III complications occurred in 3.2% of patients. Complete ablation was identified in 97.1% of tumors, with local recurrence rates of 8.5% at 10.9 months median follow up (0-80 months). Regional recurrence occurred in 34.8% of patients at 10.9 months median follow up and metastatic recurrence was seen in 8.1% of patients. One year overall survival was 80.0% and 2-year survival was 61.5%.

CONCLUSIONS

We propose that laparoscopic MWA offers a low morbidity approach for treatment of HCC affording low rates of local recurrence even for patients with significant underlying liver dysfunction. This large series offers insight into outcomes of this modality as definitive treatment for patients with HCC.

High-Frequency Irreversible Electroporation: Safety and Efficacy of Next-Generation Irreversible Electroporation Adjacent to Critical Hepatic Structures

Irreversible electroporation (IRE) is a nonthermal ablation modality employed to induce in situ tissue-cell death. This study sought to evaluate the efficacy of a novel high-frequency IRE (H-FIRE) system to perform hepatic ablations across, or adjacent to, critical vascular and biliary structures. Using ultrasound guidance H-FIRE electrodes were placed across, or adjacent to, portal pedicels, hepatic veins, or the gall bladder in a porcine model. H-FIRE pulses were delivered (2250 V, 2-5-2 pulse configuration) in the absence of cardiac synchronization or intraoperative paralytics. Six hours after H-FIRE the liver was resected and analyzed. Nine ablations were performed in 3 separate experimental groups (major vessels straddled by electrodes, electrodes placed adjacent to major vessels, electrodes placed adjacent to gall bladder). Average ablation time was 290 ± 63 seconds. No electrocardiogram abnormalities or changes in vital signs were observed during H-FIRE. At necropsy, no vascular damage, coagulated-thermally desiccated blood vessels, or perforated biliary structures were noted. Histologically, H-FIRE demonstrated effective tissue ablation and uniform induction of apoptotic cell death in the parenchyma independent of vascular or biliary structure location. Detailed microscopic analysis revealed minor endothelial damage within areas subjected to H-FIRE, particularly in regions proximal to electrode insertion. These data indicate H-FIRE is a novel means to perform rapid, reproducible IRE in liver tissue while preserving gross vascular/biliary architecture. These characteristics raise the potential for long-term survival studies to test the viability of this technology toward clinical use to target tumors not amenable to thermal ablation or resection.

Building the Nonuniversity, Tertiary Care Center Hepatobiliary and Pancreatic Surgery Practice: Structural and Financial Considerations

Early in their careers, many new surgeons lack the background and experience to understand essential components needed to build a surgical practice. Surgical resident education is often devoid of specific instruction on the business of medicine and practice management. In particular, hepatobiliary and pancreatic (HPB) surgeons require many key components to build a successful practice secondary to significant interdisciplinary coordination and a scope of complex surgery, which spans challenging benign and malignant disease processes. In the following, we describe the required clinical and financial components for developing a successful HPB surgery practice in the nonuniversity tertiary care center. We discuss significant financial considerations for understanding community need and hospital investment, contract establishment, billing, and coding. We summarize the structural elements and key personnel necessary for establishing an effectual HPB surgical team. This article provides useful, essential information for a new HPB surgeon looking to establish a surgical practice. It also provides insight for health-care administrators as to the value an HPB surgeon can bring to a hospital or health-care system.

Building the Nonuniversity, Tertiary Care Center Hepatobiliary and Pancreatic Surgery Practice: Structural and Financial Considerations

Early in their careers, many new surgeons lack the background and experience to understand essential components needed to build a surgical practice. Surgical resident education is often devoid of specific instruction on the business of medicine and practice management. In particular, hepatobiliary and pancreatic (HPB) surgeons require many key components to build a successful practice secondary to significant interdisciplinary coordination and a scope of complex surgery, which spans challenging benign and malignant disease processes. In the following, we describe the required clinical and financial components for developing a successful HPB surgery practice in the nonuniversity tertiary care center. We discuss significant financial considerations for understanding community need and hospital investment, contract establishment, billing, and coding. We summarize the structural elements and key personnel necessary for establishing an effectual HPB surgical team. This article provides useful, essential information for a new HPB surgeon looking to establish a surgical practice. It also provides insight for health-care administrators as to the value an HPB surgeon can bring to a hospital or health-care system.

MRI Brain Volume Measurements in Infantile Neuronal Ceroid Lipofuscinosis

BACKGROUND AND PURPOSE

Infantile neuronal ceroid lipofuscinosis is a devastating neurodegenerative storage disease caused by palmitoyl-protein thioesterase 1 deficiency, which impairs degradation of palmitoylated proteins (constituents of ceroid) by lysosomal hydrolases. Consequent lysosomal ceroid accumulation leads to neuronal injury, resulting in rapid neurodegeneration and childhood death. As part of a project studying the treatment benefits of a combination of cysteamine bitartrate and N-acetyl cysteine, we made serial measurements of patients' brain volumes with MR imaging.

MATERIALS AND METHODS

Ten patients with infantile neuronal ceroid lipofuscinosis participating in a treatment/follow-up study underwent brain MR imaging that included high-resolution T1-weighted images. After manual placement of a mask delineating the surface of the brain, a maximum-likelihood classifier was applied to determine total brain volume, further subdivided as cerebrum, cerebellum, brain stem, and thalamus. Patients' brain volumes were compared with those of a healthy population.

RESULTS

Major subdivisions of the brain followed similar trajectories with different timing. The cerebrum demonstrated early, rapid volume loss and may never have been normal postnatally. The thalamus dropped out of the normal range around 6 months of age; the cerebellum, around 2 years of age; and the brain stem, around 3 years of age.

CONCLUSIONS

Rapid cerebral volume loss was expected on the basis of previous qualitative reports. Because our study did not include a nontreatment arm and because progression of brain volumes in infantile neuronal ceroid lipofuscinosis has not been previously quantified, we could not determine whether our intervention had a beneficial effect on brain volumes. However, the level of quantitative detail in this study allows it to serve as a reference for evaluation of future therapeutic interventions.

Induction of rapid, reproducible hepatic ablations using next-generation, high frequency irreversible electroporation (H-FIRE) in vivo

INTRODUCTION

Irreversible electroporation (IRE) offers an alternative to thermal tissue ablation in situ. High-frequency IRE (H-FIRE), employing ultra-short bipolar electrical pulses, may overcome limitations associated with existing IRE technology to create rapid, reproducible liver ablations in vivo.

METHODS

IRE electrodes (1.5 cm spacing) were inserted into the hepatic parenchyma of swine (n = 3) under surgical anesthesia. In the absence of paralytics or cardiac synchronization five independent H-FIRE ablations were performed per liver using 100, 200, or 300 pulses (2250 V, 2-5-2 μs configuration). Animals were maintained under isoflurane anesthesia for 6 h prior to analysis of ablation size, reproducibility, and apoptotic cell death.

RESULTS

Mean ablation time was 230 ± 31 s and no EKG abnormalities occurred during H-FIRE. In 1/15 HFIRE's minor muscle twitch (rectus abdominis) was recorded. Necropsy revealed reproducible ablation areas (34 ± 4 mm(2), 88 ± 11 mm(2) and 110 ± 11 mm(2); 100-, 200- and 300-pulses respectively). Tissue damage was predominantly apoptotic at pulse delivery ≤200 pulses, after which increasing evidence of tissue necrosis was observed.

CONCLUSION

H-FIRE can be used to induce rapid, predictable ablations in hepatic tissue without the need for intraoperative paralytics or cardiac synchronization. These advantages may overcome limitations that restrict currently available IRE technology for hepatic ablations.

Comparing early and delayed repair of common bile duct injury to identify clinical drivers of outcome and morbidity

BACKGROUND

Outcomes following repair of common bile duct injury (CBDI) are influenced by center and surgeon experience. Determinants of morbidity related to timing of repair are not fully described in this population.

METHODS

Patients with CBDI managed surgically at a single center from January 2008 to June 2015 were retrospectively reviewed. Outcomes of patients undergoing early (≤48 h from injury) and delayed (>48 h) repair were compared. Predictive modeling for readmission was performed for patients undergoing delayed repair.

RESULTS

In total, 61 patients underwent surgical biliary reconstruction. Between the early and delayed repair groups, no differences were found in patient demographics, injury classification subtype, vasculobiliary injury (VBI) incidence, hospital length of stay, 30-day readmission rate, or 90-day mortality rate. Patients undergoing delayed repair exhibited increased chance of readmission if VBI was present or if multiple endoscopic procedures were performed prior to repair. A predictive model was constructed with these variables (ROC 0.681).

CONCLUSION

When managed by a tertiary hepatopancreatobiliary center, equivalent outcomes can be realized for patients undergoing early and delayed repair of CBDI. Establishment of evidence-based consensus guidelines for evaluation and treatment of CBDI may allow identification of factors that drive morbidity and predict clinical outcomes in this population.

Qualities and characteristics of successfully matched North American HPB surgery fellowship candidates

BACKGROUND

Hepato-pancreato-biliary (HPB) fellowships in North America are difficult to secure with an acceptance rate of 1 in 3 applicants. Desirable characteristics in an HPB surgery applicant have not been previously reported. This study examines the perceptions of trainees and HPB program directors with regards to positive attributes in applicants for HPB fellowships.

METHODS

Parallel surveys were distributed by email with a web-link to current and recent HPB fellows in North America (from the past 5 years) with questions addressing the following domains: surgical training, research experience, and mentorship. A similar survey was distributed to HPB fellowship program directors in North America requesting their opinion as to the importance of these characteristics in potential applicants.

RESULTS

32 of 60 of surveyed fellows and 21 of 38 of surveyed program directors responded between November 2014-February 2015. Fellows overall came from fairly diverse backgrounds (13/32 were overseas medical graduates) about one third of respondents having had some prior research experience. Program directors gave priority to the applicant's interview, curriculum vitae, and their recommendation letters (in order of importance). Both the surveyed fellows and program directors felt that the characteristics most important in a successful HPB fellowship candidate include interpersonal skills, perceived operative skills, and perceived fund of knowledge.

CONCLUSION

Results of this survey provide useful and practical information for trainees considering applying to an HPB fellowship program.

Drain amylase aids detection of anastomotic leak after esophagectomy

BACKGROUND

Anastomotic leak following esophagectomy is associated with significant morbidity and mortality. As hospital length of stay decreases, the timely diagnosis of leak becomes more important. We evaluated CT esophagram, white blood count (WBC), and drain amylase levels in the early detection of anastomotic leak.

METHODS

The diagnostic performance of CT esophagram, drain amylase >800 IU/L, and WBC >12,000/µL within the first 10 days after surgery in predicting leak at any time after esophagectomy was calculated.

RESULTS

Anastomotic leak occurred in 13 patients (13%). CT esophagram performed within 10 days of surgery diagnosed six of these leaks with a sensitivity of 0.54. Elevation in drain amylase level within 10 days of surgery diagnosed anastomotic leak with a sensitivity of 0.38. When the CT esophagram and drain amylase were combined, the sensitivity rose to 0.69 with a specificity of 0.98. WBC elevation had a sensitivity of 0.92, with a specificity of 0.34. Among 30 patients with normal drain amylase and a normal WBC, one developed an anastomotic leak.

CONCLUSIONS

Drain amylase adds to the sensitivity of CT esophagram in the early detection of anastomotic leak. Selected patients with normal drain amylase levels and normal WBC may be able to safely forgo CT esophagram.

Postmarketing Analysis of a Novel, Cordless Ultrasonic Dissector

Introduction Tissue dissection and vessel sealing is performed using a variety of energy sources and surgical devices. We describe the postmarketing analysis of a cordless ultrasonic dissector and vessel sealer in a series of general and gynecological procedures. Methods Patients were prospectively screened and consented for participation. Data collected included demographics, device activations/seals and failures, and patient complications. Surgeons were surveyed following each case. Data was analyzed using standard statistical methods. Results A total of 110 patients were consented and participated in the study. The most frequently performed procedures were bilateral salpingo-oophorectomy (n = 48) and total laparoscopic hysterectomy (n = 36). Mean age was 54.2 years and 79.2% were female. The most frequent number of device activations per case was between 26 and 50 (36.6%). Five failed seals occurred out of 4858 total estimated seals (0.11%). Failed seals were felt to be due to thickened, scarred tissue not amenable to device compression. There were no patient intraoperative complications related to the device itself. Overall, surgeons felt the device was extremely easy to use (97.6%) and no visual obstruction due to steam from the device was encountered (95%). Ninety-five percent of surgeons felt the device was beneficial for soft tissue dissection and vessel sealing. Conclusion Sonicision is safe and effective for use in dissection of soft tissues and vessel sealing in a variety of laparoscopic and open procedures. In this study, there were no complications related to the device itself. The remarkable cordless design of this device enhances its ease of use with overall excellent effectiveness.

High frequency irreversible electroporation (H-FIRE) as a novel method of targeted cell death

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Background: Irreversible electroporation unlike ablation is excellent in inducing cell death via apoptosis. It, however, has disadvantages of electrical conduction via cardiac and nervous tissue. This results in requiring cardiac monitoring and general anesthesia and paralytics while performing electroporation. We hypothesized a novel high-frequency IRE (H-FIRE) system employing ultra-short bipolar pulses would obviate the need for cardiac synchronization and paralytics while maintaining measurable effect on cell death. Methods: Female swine (55-65Kg) were used. Two H-FIRE electrodes were inserted into the liver (1.5-cm spacing). In the absence of paralytics H-FIRE pulses were delivered (2250V, 2-5-2 pulse configuration) at different on times (100 vs. 200μs) or number of pulses (100 vs. 300). Next electrodes were placed across major hepatic vascular structures and H-FIRE performed. At conclusion tissue was resected and analyzed histologically. Results: 24 H-FIREs were performed (mean ablation time 275 secs). No EKG abnormalities or changes in vital signs were measured during H-FIRE procedures. In 1/24 H-FIREs minor twitching of the rectus abdominis was recorded coinciding with pulse delivery. Histologically, tissues had effective electroporation as evidenced by cell death and caspase activity. Blinded scoring was performed for necrosis and apoptosis. Areas of cell death were predictable. No significant vascular damage or coagulated/thermally-desiccated blood was detected within major vessels following H-FIRE. Conclusions: H-FIRE is a novel way of liver electroporation. It produces predictable cell apoptosis without the requirement of paralytics and alteration of electrocardiographic signals as compared to traditional electroporation, while preserving underlying vascular integrity. Its application in cancer cell death needs to be further studied, but it has a potential for clinical use in targeting tumors with minimal morbidity and associated cardiac and neurologic side effects.