Multi-institutional review of adverse events associated with irreversible electroporation in the treatment of locally advanced pancreatic cancer

BACKGROUND

Irreversible electroporation is a novel approach for treating locally advanced pancreatic adenocarcinoma. However, this ablative technique is not without risk and has the potential to precipitate adverse events. The aim of this study was to delineate risk factors that increase this risk, as well as to elucidate the risk profile associated with irreversible electroporation in the setting of locally advanced pancreatic adenocarcinoma.

METHODS

A review of our prospective multi-institutional database from December 2015 to March 2022 of patients with locally advanced pancreatic adenocarcinoma who underwent irreversible electroporation was analyzed for adverse events. These were then compared with a control population of patients undergoing pancreatectomy for adenocarcinoma.

RESULTS

Adverse events occurred in 51 patients of the 201 patients treated with irreversible electroporation compared with 78 of the 200 patients treated with pancreatectomy. The irreversible electroporation group had a significantly greater incidence of postoperative ascites in stage 3C patients. The most common complications in the irreversible electroporation group were infectious (n = 13), gastrointestinal bleed (n = 11), and ascites (n = 7). Multivariate analysis demonstrated increased risk of severe (grade ≥3) adverse events in the irreversible electroporation cohort who received high dose, neoadjuvant radiation (hazard ratio, 2.4; 95% confidence interval, 1.4-5.4), irreversible electroporation electrodes bracketing the superior mesenteric artery, superior mesenteric vein, and portal venous vein (hazard ratio, 1.9; 95% confidence interval, 1.3-3.4), and who had a bile duct stent in place for >6 months (hazard ratio, 1.7; 95% confidence interval, 1.2-5.6). There were similar rates of 90-day mortality in both groups, irreversible electroporation 2.4% vs pancreatectomy 2.8%.

CONCLUSION

This study revealed a 25% rate of adverse events associated with irreversible electroporation in locally advanced pancreatic adenocarcinoma, which was significantly less (P = .004) than the 39% rate of adverse events associated with pancreatectomy in early-stage disease. Certain unique adverse events in the irreversible electroporation group have been established and should be understood in the care of these patients.

Combined pre-operative risk score predicts pancreatic leak after pancreatic resection

BACKGROUND

Post-operative pancreatic fistula (POPF) is a major complication following pancreatectomy and is currently difficult to predict pre-operatively. This study aims to validate pre-operative risk factors and develop a novel combined score for the prediction of POPF in the pre-operative setting.

METHODS

Data were collected from 2016 to 2021 for radiologic main pancreatic duct diameter (MPD), body mass index (BMI), physical status classified by American Society of Anesthesiologists (ASA), polypharmacy, mean platelet ratio (MPR), comorbidity-polypharmacy score (CPS), and a novel Combined Pancreatic Leak Prediction Score (CPLPS) (derived from MPD diameter, BMI, and CPS) were obtained from pre-operative data and analyzed for their independent association with POPF occurrence.

RESULTS

In total, 166 patients who underwent pancreatectomy with pancreatic leak (Grade A, B, and C) occurring in 51(30.7%) of patients. Pre-operative radiologic MPD diameter < 4 mm (p < 0.001), < 5 mm (p < 0.001), < 6 mm (p = 0.001), BMI ≥ 25 (p = 0.009), and ≥ 30 (p = 0.017) were independently associated with the occurrence of pancreatic leak. CPLPS was also predictive of pancreatic leak following pancreatectomy on univariate (p = 0.005) and multivariate analysis (p = 0.036).

CONCLUSION

MPD and BMI were independent risk factors predictive for the development of pancreatic leak. CPLPS, was an independent predictor of pancreatic leak following pancreatectomy and could be used to help guide surgical decision making and patient counseling.

Diagnosis of Pancreatic Cancer after Cholecystectomy in the Elderly

BACKGROUND

Previous studies evaluating whether recent cholecystectomy is associated with a pancreas cancer diagnosis are limited. We aimed to examine if cholecystectomy was performed more frequently in the year prior to cancer diagnosis than would be expected in a similar non-cancer population.

METHODS

SEER-Medicare linked files were used to identify patients with pancreatic adenocarcinoma. Cancer diagnoses were considered to be "timely" if within 2 months of cholecystectomy or "delayed" if 2-12 months after cholecystectomy. Clinical factors and survival outcomes were compared using chi-square and Kaplan-Meier analyses.

RESULTS

Rate of cholecystectomy in the year prior to diagnosis of cancer was 1.9% for the cancer group, compared to .4% in the non-cancer group (OR = 4.7, 95% CI 4.4-5.1). Differences in the cancer vs non-cancer cohorts at the time of cholecystectomy included a higher age (74 vs 70, P < .0001), more males (49.9% vs 41.7%, P < .0001), and more frequent open technique (21.0% vs 9.4%, P < .0001). Acute pancreatitis was nearly twice as common in the cancer cohort (19.1%) vs the non-cancer cohort (10.7%), P < .0001. There were no differences between patients who had a timely diagnosis after cholecystectomy compared to a delayed diagnosis with regard to age, gender, comorbidity index, race, or rural/urban designation. The rates of localized disease and subsequent resection were also similar between the delayed and timely groups. Overall unadjusted survival was no different between timely and delayed diagnoses, P = .96.

DISCUSSION

Elderly patients diagnosed with pancreatic adenocarcinoma are more likely to have had a recent cholecystectomy compared to those without.

Interval Sentinel Lymph Nodes With the Use of Routine Lymphoscintigraphy in Extremity Melanoma

INTRODUCTION

Lymphoscintigraphy (LS) helps identify drainage to interval (epitrochlear or popliteal) lymph node basins for extremity melanomas. This study evaluated how often routine LS evaluation identified an interval sentinel lymph node (SLN) and how often that node was found to have metastasis.

METHODS

A single institution, retrospective study identified patients with an extremity melanoma who underwent routine LS and SLN biopsy over a 25-y period. Comparisons of factors associated with the identification of interval node drainage and tumor status were made.

RESULTS

In 634 patients reviewed, 5.7% of patients drained to an interval SLN. Of those biopsied, 29.2% were positive for micrometastases. Among patients with biopsies of both the traditional and interval nodal basins, nearly 20% had positive interval nodes with negative SLNs in the traditional basin. Sex, age, thickness, ulceration, and the presence of mitotic figures were not predictive of identifying an interval node on LS, nor for having disease in an interval node. Anatomic location of the primary melanoma was the only identifiable risk factor, as no interval nodes were identified in melanomas of the thigh or upper arm (P ≤ 0.001).

CONCLUSIONS

Distal extremity melanomas have a moderate risk of mapping to an interval SLN. Routine LS should be considered in these patients, especially as these may be the only tumor-positive nodes. However, primary extremity melanomas proximal to the epitrochlear or popliteal nodal basins do not map to interval nodes, and improved savings and workflow could be realized by selectively omitting routine LS in such patients.

Racial and Ethnic Disparities in Operative Experience Among General Surgery Residents: A Multi-Institutional Study from the US ROPE Consortium

OBJECTIVE

To determine the relationship between race/ethnicity and case volume among graduating surgical residents.

BACKGROUND

Racial/ethnic minority individuals face barriers to entry and advancement in surgery; however, no large-scale investigations of the operative experience of racial/ethnic minority residents have been performed.

METHODS

A multi-institutional retrospective analysis of the Accreditation Council for Graduate Medical Education case logs of categorical general surgery residents at 20 programs in the US Resident OPerative Experience Consortium database was performed. All residents graduating between 2010 and 2020 were included. The total, surgeon chief, surgeon junior, and teaching assistant case volumes were compared between racial/ethnic groups.

RESULTS

The cohort included 1343 residents. There were 211 (15.7%) Asian, 65 (4.8%) Black, 73 (5.4%) Hispanic, 71 (5.3%) "Other" (Native American or Multiple Race), and 923 (68.7%) White residents. On adjusted analysis, Black residents performed 76 fewer total cases (95% CI, -109 to -43, P <0.001) and 69 fewer surgeon junior cases (-98 to -40, P <0.001) than White residents. Comparing adjusted total case volume by graduation year, both Black residents and White residents performed more cases over time; however, there was no difference in the rates of annual increase (10 versus 12 cases per year increase, respectively, P =0.769). Thus, differences in total case volume persisted over the study period.

CONCLUSIONS

In this multi-institutional study, Black residents graduated with lower case volume than non-minority residents throughout the previous decade. Reduced operative learning opportunities may negatively impact professional advancement. Systemic interventions are needed to promote equitable operative experience and positive culture change.

A multi-institutional study from the US ROPE consortium examining factors associated with endocrine surgery exposure for general surgery residents

BACKGROUND

Prior analyses of general surgery resident case logs have indicated a decline in the number of endocrine procedures performed during residency. This study aimed to identify factors contributing to the endocrine operative experience of general surgery residents and compare those who matched in endocrine surgery fellowship with those who did not.

METHODS

We analyzed the case log data of graduates from 18 general surgery residency programs in the US Resident Operative Experience Consortium over an 11-year period.

RESULTS

Of the 1,240 residents we included, 17 (1%) matched into endocrine surgery fellowships. Those who matched treated more total endocrine cases, including more thyroid, parathyroid, and adrenal cases, than those who did not (81 vs 37, respectively, P < .01). Program-level factors associated with increased endocrine volume included endocrine-specific rotations (+10, confidence interval 8-12, P < .01), endocrine-trained faculty (+8, confidence interval 7-10, P < .01), and program co-location with otolaryngology residency (+5, confidence interval 2 -8, P < .01) or endocrine surgery fellowship (+4, confidence interval 2-6, P < .01). Factors associated with decreased endocrine volume included bottom 50th percentile in National Institute of Health funding (-10, confidence interval -12 to -8, P < .01) and endocrine-focused otolaryngologists (-3, confidence interval -4 to -1, P < .01).

CONCLUSION

Several characteristics are associated with a robust endocrine experience and pursuit of an endocrine surgery fellowship. Modifiable factors include optimizing the recruitment of dedicated endocrine surgeons and the inclusion of endocrine surgery rotations in general surgery residency.

Predictive Ability of Comorbidity Indices for Surgical Morbidity and Mortality: a Systematic Review and Meta-analysis

BACKGROUND

Several contemporary risk stratification tools are now being used since the development of the Charlson Comorbidity Index (CCI) in 1987. The purpose of this systematic review and meta-analysis was to compare the utility of commonly used co-morbidity indices in predicting surgical outcomes.

METHODS

A comprehensive review was performed to identify studies reporting an association between a pre-operative co-morbidity measurement and an outcome (30-day/in-hospital morbidity/mortality, 90-day morbidity/mortality, and severe complications). Meta-analysis was performed on the pooled data.

RESULTS

A total of 111 included studies were included with a total cohort size 25,011,834 patients. The studies reporting the 5-item Modified Frailty Index (mFI-5) demonstrated a statistical association with an increase in the odds of in-hospital/30-day mortality (OR:1.97,95%CI: 1.55-2.49, p < 0.01). The pooled CCI results demonstrated an increase in the odds for in-hospital/30-day mortality (OR:1.44,95%CI: 1.27-1.64, p < 0.01). Pooled results for co-morbidity indices utilizing a scale-based continuous predictor were significantly associated with an increase in the odds of in-hospital/30-day morbidity (OR:1.32, 95% CI: 1.20-1.46, p < 0.01). On pooled analysis, the categorical results showed a higher odd for in-hospital/30-day morbidity (OR:1.74,95% CI: 1.50-2.02, p < 0.01). The mFI-5 was significantly associated with severe complications (Clavien-Dindo ≥ III) (OR:3.31,95% CI:1.13-9.67, p < 0.04). Pooled results for CCI showed a positive trend toward severe complications but were not significant.

CONCLUSION

The contemporary frailty-based index, mFI-5, outperformed the CCI in predicting short-term mortality and severe complications post-surgically. Risk stratification instruments that include a measure of frailty may be more predictive of surgical outcomes compared to traditional indices like the CCI.

Infection reporting in patients undergoing irreversible electroporation of locally advanced pancreatic cancer

BACKGROUND

Intraoperative bile cultures (IOBCs) taken during pancreatic surgery are commonly performed and there has been limited evidence that a positive IOBC could aid in perioperative adverse event (AE) management. Therefore, this study aims to describe infection management in patients undergoing irreversible electroporation (IRE).

METHODS

An Institutional Review Board (IRB)-approved prospective database was utilized from 8/2016 to 6/2022, with 127 pancreatic adenocarcinoma patients included.

RESULTS

A total of 28 patients that underwent IRE also had a simultaneous positive IOBC and the remaining 99 patients that underwent IRE had negative IOBC. A total of 11(39%) of the patients with a positive IOBC had AE's, and 38 (38%) of the patients with negative IOBC had AE's. Both groups had similar rates of AEs leading to new hospitalization and prolonged hospitalizations. Overall, there was no correlation between a positive IOBC and a patient developing an AE.

CONCLUSIONS

The findings of this study provide insights that improve the infectious management of patients undergoing IRE.

Optimal Dosing and Patient Selection for Electrochemotherapy in Solid Abdominal Organ and Bone Tumors

The primary aim of this study was to analyze studies that use electrochemotherapy (ECT) in "deep-seated" tumors in solid organs (liver, kidney, bone metastasis, pancreas, and abdomen) and understand the similarities between patient selection, oncologic selection, and use of new procedures and technology across the organ systems to assess response rates. A literature search was conducted using the term "Electrochemotherapy" in the title field using publications from 2017 to 2023. After factoring in inclusion and exclusion criteria, 29 studies were analyzed and graded based on quality in full. The authors determined key patient and oncologic selection characteristics and ECT technology employed across organ systems that yielded overall responses, complete responses, and partial responses of the treated tumor. It was determined that key selection factors included: the ability to be administered bleomycin, life expectancy greater than three months, unrespectability of the lesion being treated, and a later stage, more advanced cancer. Regarding oncologic selection, all patient cohorts had received chemotherapy or surgery previously but had disease recurrence, making ECT the only option for further treatment. Lastly, in terms of the use of technology, the authors found that studies with better response rates used the ClinporatorTM and updated procedural guidelines by SOP. Thus, by considering patient, oncologic, and technology selection, ECT can be further improved in treating lesions in solid organs.

Irreversible electroporation augments β-glucan induced trained innate immunity for the treatment of pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic cancer (PC) is a challenging diagnosis that is yet to benefit from the advancements in immuno-oncologic treatments. Irreversible electroporation (IRE), a non-thermal method of tumor ablation, is used in treatment of select patients with locally-advanced unresectable PC and has potentiated the effect of certain immunotherapies. Yeast-derived particulate β-glucan induces trained innate immunity and successfully reduces murine PC tumor burden. This study tests the hypothesis that IRE may augment β-glucan induced trained immunity in the treatment of PC.

METHODS

β-Glucan-trained pancreatic myeloid cells were evaluated ex vivo for trained responses and antitumor function after exposure to ablated and unablated tumor-conditioned media. β-Glucan and IRE combination therapy was tested in an orthotopic murine PC model in wild-type and Rag-/- mice. Tumor immune phenotypes were assessed by flow cytometry. Effect of oral β-glucan in the murine pancreas was evaluated and used in combination with IRE to treat PC. The peripheral blood of patients with PC taking oral β-glucan after IRE was evaluated by mass cytometry.

RESULTS

IRE-ablated tumor cells elicited a potent trained response ex vivo and augmented antitumor functionality. In vivo, β-glucan in combination with IRE reduced local and distant tumor burden prolonging survival in a murine orthotopic PC model. This combination augmented immune cell infiltration to the PC tumor microenvironment and potentiated the trained response from tumor-infiltrating myeloid cells. The antitumor effect of this dual therapy occurred independent of the adaptive immune response. Further, orally administered β-glucan was identified as an alternative route to induce trained immunity in the murine pancreas and prolonged PC survival in combination with IRE. β-Glucan in vitro treatment also induced trained immunity in peripheral blood monocytes obtained from patients with treatment-naïve PC. Finally, orally administered β-glucan was found to significantly alter the innate cell landscape within the peripheral blood of five patients with stage III locally-advanced PC who had undergone IRE.

CONCLUSIONS

These data highlight a relevant and novel application of trained immunity within the setting of surgical ablation that may stand to benefit patients with PC.

Patient Selection and Outcomes of Laparoscopic Microwave Ablation of Hepatocellular Carcinoma

Background: Laparoscopic microwave ablation (MWA) of hepatocellular carcinoma is underutilized and predictors of survival in this setting are not well characterized. Methods: The prognostic value of clinicopathologic variables was evaluated on progression-free survival (PFS) and overall survival (OS) by univariate and multivariate analyses. The aim of this study was to evaluate a preferred laparoscopic MWA approach in HCC patients that are not candidates for percutaneous ablation and further classify clinicopathologic factors that may predict survival outcomes following operative MWA in the setting of primary HCC. Results: 184 patients with HCC (median age 66, (33–86), 70% male) underwent laparoscopic MWA (N = 162, 88% laparoscopic) compared to 12% undergoing open MWA (N = 22). Median PFS was 29.3 months (0.2–170) and OS was 44.2 months (2.8–170). Ablation success was confirmed in 100% of patients. Ablation recurrence occurred in 3% (6/184), and local/hepatic recurrence occurred in 34%, at a median time of 19 months (9–18). Distant progression was noted in 8%. Median follow up was 34.1 months (6.4–170). Procedure-related complications were recorded in six (9%) patients with one 90-day mortality. Further, >1 lesion, AFP levels ≥ 80 ng/mL, and an “invader” on pre-operative radiology were associated with increased risk of progression (>1 lesion HR 2.92, 95% CI 1.06 –7.99, p = 0.04, AFP ≥ 80 ng/mL HR 4.16, 95% CI 1.71–10.15, p = 0.002, Invader HR 3.16, 95% CI 1.91–9.15, p = 0.002 ) and mortality (>1 lesion HR 3.62, 95% CI 1.21–10.81, p = 0.02], AFP ≥ 80 ng/mL HR 2.87, 95% CI 1.12–7.35, p = 0.01, Invader HR 3.32, 95% CI 1.21–9.81, p = 0.02). Conclusions: Preoperative lesion number, AFP ≥ 80 ng/mL, and an aggressive imaging characteristic (Invader) independently predict PFS and OS following laparoscopic operative MWA.

Continuous manual agitation significantly improves temperature distribution during closed hyperthermic intraperitoneal chemotherapy: Results of a porcine model

BACKGROUND

Debate persists regarding the need for shaking during hyperthermic intraperitoneal chemotherapy. Studies assessing the thermal behaviors of the perfusate throughout the abdomen during hyperthermic intraperitoneal chemotherapy are limited.

METHODS

A closed hyperthermic intraperitoneal chemotherapy technique was performed in an institutional International Animal Care and Use Committee approved porcine model targeting a 41°C outflow temperature. Continuous temperature monitoring was conducted. Abdominal shaking was performed for 60 second intervals and temperatures were allowed to equilibrate without shaking between intervals. Temperature distributions and changes due to shaking were evaluated. These findings were validated against human subjects' data.

RESULTS

The experimental procedure was conducted in 2 different animals and with 6 total shaking intervals assessed. Without shaking, temperatures were highly variable ranging between 38.0 to 42.2°C. Shaking the abdomen reduced the mean range of temperatures across all locations observed from 3.9°C to 0.8°C (P < .01). The locations of the most divergent temperatures varied based on perfusion cannula position. The point of minimum temperature heterogeneity was achieved in 28.3 (19.1-37.5) seconds. After shaking stopped, heterogeneity equal to the baseline measurements was seen on average within 25.7 (13.3-38.0) seconds. The outflow catheter differed from the system mean temperature by 1.4°C and from the coldest-reading probe by 2.8°C and outperformed the inflow catheter for all time points. With shaking these were significantly reduced to 0.4°C (P < .01) and 0.6°C (P < .01). The patient data mirrored that of the pig data.

CONCLUSION

Shaking significantly reduces temperature variability within the abdomen during hyperthermic intraperitoneal chemotherapy, and significantly improves the ability of the outflow catheter to estimate internal temperatures.

Impact of margin accentuation with intraoperative irreversible electroporation on local recurrence in resected pancreatic cancer

BACKGROUND

The purpose of this study was to evaluate the rates of local recurrence and margin positivity in patients with borderline resectable pancreatic cancer after pancreatectomy with or without irreversible electroporation with margin accentuation.

METHODS

Prospective data for preoperative stages IIB (borderline resectable) and III were evaluated, with 75 patients undergoing pancreatectomy with irreversible electroporation with margin accentuation compared to 71 patients who underwent pancreatectomy alone from March 2010 to November 2020.

RESULTS

Both irreversible electroporation with margin accentuation and pancreatectomy-alone groups were similar for body mass index, Charleston comorbidity index, and sex. The irreversible electroporation with margin accentuation group had significantly greater preoperative stage III (irreversible electroporation 83% vs pancreatectomy alone 51%; P = .0001), with similar tumor location (head 64% vs 72%) and tumor size (median 2.9 vs 2.8). Neoadjuvant/induction chemotherapy and prior radiation therapy was similar in both groups (irreversible electroporation with margin accentuation 89% vs 72%). Surgical therapy included a greater percentage of pancreaticoduodenectomy in the pancreatectomy-alone group. Despite greater stage and greater percentage of margin positivity (irreversible electroporation with margin accentuation 27% vs 20%; P = not significant), rates of local recurrence were similar. The mean disease-free interval for local recurrence from time of diagnosis was similar (irreversible electroporation with margin accentuation 15.8 vs 16.5 pancreatectomy alone; P = not significant) and time of treatment (irreversible electroporation with margin accentuation 9.4 vs 10.5 months; P = not significant). Overall survival was improved with the irreversible electroporation with margin accentuation group, with a mean of 34.2 months versus 27.9 months in the pancreatectomy-alone group.

CONCLUSION

Irreversible electroporation with margin accentuation is safe and effective in stages IIB and III pancreatic adenocarcinomas that are technically resectable. Despite higher margin positivity rates, the time to local recurrence and the effects of recurrence were the same in the pancreatectomy-alone group.

A meta-analysis and systematic review of the comparison of laparoscopic ablation to percutaneous ablation for hepatic malignancies

BACKGROUND

The optimal access for thermal ablation of the liver has not been evaluated in the literature for the laparoscopic versus percutaneous techniques. The aim of this manuscript was to determine the optimal ablation technique and patient selection for hepatic malignancies by comparing the efficacy and recurrence-free survival of laparoscopic and percutaneous thermal ablation.

METHODS

A detailed literature search was made in PubMed, Web of Science, Google scholar, and EMBASE for related research publications. The data were extracted and assessed by two reviewers independently. Analysis of pooled data was performed, and Odds Ratio (OR) or Hazard Ratio (HR) with corresponding confidence intervals (CIs) was calculated and summarized respectively.

RESULTS

A total of 10 articles were included with 1916 ablation patients. Laparoscopic ablation success (Median 100%) was found to be higher than percutaneous ablation success (median 89.4%) (p = ns). There was a higher percentage of both local and non-local hepatic recurrence in the patients treated with percutaneous ablation versus laparoscopic ablation. Meta-analysis indicated no difference in the adjusted hazard rate of recurrence by procedure type (p = 0.94). Laparoscopic ablation had a higher percentage of complications compared to percutaneous ablation (median lap 14.5% vs. perc 3.3%).

CONCLUSIONS

While laparoscopic and percutaneous ablation are both effective interventions for hepatic malignancies, laparoscopic ablation was found to have improved ablation success and less local and non-local hepatic recurrence compared to percutaneous ablation.

Locally advanced pancreatic cancer: a reliable contraindication to resection in the modern era?

BACKGROUND

The aim of this study is to present radiologically designated LAPC found to be resectable upon surgical exploration and evaluate the outcomes of such resections.

METHODS

Sequential LAPC patients between 2013 and 2019 were staged and underwent resection were included in the analysis of both perioperative and long-term outcomes.

RESULTS

Twenty-eight patients with radiologically-designated LAPC underwent surgical resection after chemotherapy with a median follow-up of 31.7 m,75% underwent pancreaticoduodenectomy. The margin positivity and local recurrence rates were 21.4% and 35.7%, respectively. When compared to the 30 BRPC controls, the LAPC group had a higher rates of an arterial resection (11vs.1; p = 0.002), but the groups were similar with regard to all other preoperative and intraoperative variables (p < 0.05). Perioperative morbidity rates were similar (25.9%vs21.4%; p = 0.53). The LAPC and BRPC groups were also equivalent with respect to median recurrence-free survival (9.0mo; 95%CI 6.3, 11.7vs.8.3mo; 95%CI 5.4, 11.2) and median overall survival (19.9mo; 95%CI 17.0, 22.7 vs. 19.9mo; 95%CI 14.8, 25.1), respectively.

CONCLUSION

Despite a radiologic designation of locally advanced pancreatic cancer, certain subtypes of LAPC warrant surgical exploration provided the operative surgeon is prepared for major arterial and/or venous resection. Pancreatectomy in these patients has acceptable morbidity and oncologic outcomes, similar to patients who are radiologically borderline resectable.

A multi-institutional study from the US ROPE Consortium examining factors associated with directly entering practice upon residency graduation

BACKGROUND

There is concern regarding the competency of today's general surgery graduates as a large proportion defer independent practice in favor of additional fellowship training. Little is known about the graduates who directly enter general surgery practice and if their operative experiences during residency differ from graduates who pursue fellowship.

METHODS

Nineteen Accreditation Council for Graduate Medical Education-accredited general surgery programs from the US Resident OPerative Experience Consortium were included. Demographics, career choice, and case logs from graduates between 2010 to 2020 were analyzed.

RESULTS

There were 1,264 general surgery residents who graduated over the 11-year period. A total of 248 (19.6%) went directly into practice and 1,016 (80.4%) pursued fellowship. Graduates directly entering practice were more likely to be a high-volume resident (43.1% vs 30.5%, P < .01) and graduate from a high-volume program (49.2% vs 33.0%, P < .01). Direct-to-practice graduates performed 53 more cases compared with fellowship-bound graduates (1,203 vs 1,150, P < .01). On multivariable analysis, entering directly into practice was positively associated with total surgeon chief case volume (odds ratio = 1.47, 95% confidence interval 1.18-1.84, P < .01) and graduating from a US medical school (odds ratio = 2.54, 95% confidence interval 1.45-4.44, P < .01) while negatively associated with completing a dedicated research experience (odds ratio = 0.31, 95% confidence interval 0.22-0.45, P < .01).

CONCLUSION

This is the first multi-institutional study exploring resident operative experience and career choice. These data suggest residents who desire immediate practice can tailor their experience with less research time and increased operative volume. These data may be helpful for programs when designing their experience for residents with different career goals.

Intratumoral Immunotherapy and Tumor Ablation: A Local Approach with Broad Potential

Several intratumoral immunotherapeutic agents have shown efficacy in controlling local disease; however, their ability to induce a durable systemic immune response is limited. Likewise, tumor ablation is well-established due to its role in local disease control but generally produces only a modest immunogenic effect. It has recently been recognized, however, that there is potential synergy between these two modalities and their distinct mechanisms of immune modulation. The aim of this review is to evaluate the existing data regarding multimodality therapy with intratumoral immunotherapy and tumor ablation. We discuss the rationale for this therapeutic approach, highlight novel combinations, and address the challenges to their clinical utility. There is substantial evidence that combination therapy with intratumoral immunotherapy and tumor ablation can potentiate durable systemic immune responses and should be further evaluated in the clinical setting.

Optimizing Patient Selection for Irreversible Electroporation of Locally Advanced Pancreatic Cancer: Analyses of Survival

Background

Irreversible electroporation (IRE) has emerged as a viable consolidative therapy after induction chemotherapy, in which this combination has improved overall survival of locally advanced pancreatic cancer (LAPC). Optimal timing and patient selection for irreversible electroporation remains a clinically unmet need. The aim of this study was to investigate preoperative factors that may assist in predicting progression-free and overall survival following IRE.

Methods

A multi-institutional, prospectively maintained database was reviewed for patients with LAPC treated with induction chemotherapy followed by open-technique irreversible electroporation from 7/2015-5/2019. RECIST 1.1 criteria were used to assess tumor response and radiological progression. Overall survival (OS) and progression-free survival (PFS) were recorded. Survival analyses were performed using Kaplan Meier and Cox multivariable regression analyses.

Results

187 LAPC patients (median age 62 years range, 21 – 91, 65% men, 35% women) were treated with IRE. Median PFS was 21.7 months and median OS from diagnosis was 25.5 months. On multivariable analysis, age ≤ 61 (HR 0.41, 95%CI 0.21-0.78, p<0.008) and no prior radiation (HR 0.49, 95%CI 0.26-0.94, p=0.03) were positive predictors of OS after IRE. Age ≤ 61(HR 0.53, 95%CI, 0.28-.99, p=0.046) and FOLFIRINOX followed by gemcitabine/abraxane induction chemotherapy (HR 0.37,95%CI 0.15-0.89, p=0.027) predicted prolonged PFS after IRE. Abnormal CA19-9 values at the time of surgery negatively impacted both OS (HR 2.46, 95%CI 1.28-4.72, p<0.007) and PFS (HR 2.192, 95%CI 1.143-4.201, p=0.018) following IRE.

Conclusions

Age, CA 19-9 response, avoidance of pre-IRE radiation, and FOLFIRINOX plus gemcitabine/abraxane induction chemotherapy are prominent factors to consider when referring or selecting LAPC patients to undergo IRE.

Perioperative systemic immunophenotype following irreversible electroporation (IRE) predicts recurrence

Comprehensive understanding of the immunophenotypic response to local therapy will likely be required to improve outcomes for pancreatic ductal adenocarcinoma (PDAC). While the desmoplastic stroma has rendered PDAC resistant to immunotherapies, irreversible electroporation (IRE), a non-thermal method of tumor ablation, can overcome some of this resistance and immune suppression. We studied the systemic immunophenotype of patients following local treatment of PDAC. Stored lymphocytes from peripheral blood collected pre- and post-operatively for patients with PDAC who underwent surgical treatment from 12/2018 until 12/2019 were prepared for mass cytometry and a 30-marker panel identifying 37 immune-cell clusters were analyzed and compared to all clinical parameters. Stored lymphocytes from patient samples were collected pre-operatively postoperatively (Day 1, 3, 5 and 14) and during surveillance (Month 3, 6, 9 and 12). Thirty patients with locally advanced pancreatic cancer (LAPC) who underwent IRE were evaluated prospectively for changes in their immunophenotype. No significant differences in baseline demographics or tumor markers were identified. CA19-9 levels were significantly higher among patients who developed a recurrence (P=0.03). In the early perioperative period, CD4 and CD8 central memory cells were significantly higher among patients who did not recur (P=0.02 and 0.009 respectively). These findings were maintained in the late (>3 month) surveillance period. Early natural killer (NK) cells were significantly higher among those who did not recur (P=0.004) in the early postoperative period. The early immune-cell populations of CD4 and CD8 central memory cells and early NK cells were significantly higher among populations who did not recur following IRE for PDAC during the study period, with maintenance of the CD4 and CD8 central memory populations during later surveillance. Monitoring the early immunophenotype may offer opportunities to augment the immune response following tumor-disruptive IRE for PDAC.

Radioembolization With Chemotherapy for Colorectal Liver Metastases: A Randomized, Open-Label, International, Multicenter, Phase III Trial

PURPOSE

To study the impact of transarterial Yttrium-90 radioembolization (TARE) in combination with second-line systemic chemotherapy for colorectal liver metastases (CLM).

METHODS

In this international, multicenter, open-label phase III trial, patients with CLM who progressed on oxaliplatin- or irinotecan-based first-line therapy were randomly assigned 1:1 to receive second-line chemotherapy with or without TARE. The two primary end points were progression-free survival (PFS) and hepatic PFS (hPFS), assessed by blinded independent central review. Random assignment was performed using a web- or voice-based system stratified by unilobar or bilobar disease, oxaliplatin- or irinotecan-based first-line chemotherapy, and KRAS mutation status.

RESULTS

Four hundred twenty-eight patients from 95 centers in North America, Europe, and Asia were randomly assigned to chemotherapy with or without TARE; this represents the intention-to-treat population and included 215 patients in the TARE plus chemotherapy group and 213 patients in the chemotherapy alone group. The hazard ratio (HR) for PFS was 0.69 (95% CI, 0.54 to 0.88; 1-sided P = .0013), with a median PFS of 8.0 (95% CI, 7.2 to 9.2) and 7.2 (95% CI, 5.7 to 7.6) months, respectively. The HR for hPFS was 0.59 (95% CI, 0.46 to 0.77; 1-sided P < .0001), with a median hPFS of 9.1 (95% CI, 7.8 to 9.7) and 7.2 (95% CI, 5.7 to 7.6) months, respectively. Objective response rates were 34.0% (95% CI, 28.0 to 40.5) and 21.1% (95% CI, 16.2 to 27.1; 1-sided P = .0019) for the TARE and chemotherapy groups, respectively. Median overall survival was 14.0 (95% CI, 11.8 to 15.5) and 14.4 months (95% CI, 12.8 to 16.4; 1-sided P = .7229) with a HR of 1.07 (95% CI, 0.86 to 1.32) for TARE and chemotherapy groups, respectively. Grade 3 adverse events were reported more frequently with TARE (68.4% v 49.3%). Both groups received full chemotherapy dose intensity.

CONCLUSION

The addition of TARE to systemic therapy for second-line CLM led to longer PFS and hPFS. Further subset analyses are needed to better define the ideal patient population that would benefit from TARE.

Hepatopancreatobiliary readmission score out performs administrative LACE+ index as a predictive tool of readmission

BACKGROUND

This study aims to compare the LACE + readmission index to a novel hepatopancreatobiliary readmission risk score (HRRS) in predicting post-operative hepatopancreatobiliary (HPB) cancer patient readmissions.

METHODS

A retrospective review of 104 postoperative HPB cancer patients from January 2017 to July of 2019 was performed. Univariable and multivariable analyses were utilized.

RESULTS

The LACE + index did not predict 30-day (OR 1.01, 95% CI, 0.97-1.05, p = 0.81, c-statistic = 0.52) or 90-day (OR 1.02, 95% CI, 0.98-1.05, p = 0.43) readmission. Patients readmitted within 30 days had significantly increased HRRS scores compared to those who were not (0 vs 34, p < 0.001). A single unit increase in HRRS corresponded to a 6.5% increased risk of readmission; (OR 1.065, 95% CI, 1.038-1.094, p < 0.0001). HRRS independently predicted 30-day (OR 1.07, 95% CI, 1.04-1.11, p < 0.0001) and 90-day postoperative readmission (OR 1.05, 95% CI 1.03-1.08, p < 0.0001).

CONCLUSIONS

HRRS better predicts postoperative readmissions for HPB surgical patients compared to LACE+. Accurate assessment of postoperative readmission must include readmission scores focused on clinically relevant perioperative parameters.

Exocrine Pancreatic Insufficiency After Pancreatectomy for Malignancy: Systematic Review and Optimal Management Recommendations

BACKGROUND

Exocrine pancreatic insufficiency (EPI) occurs when pancreatic enzyme activity in the intestinal lumen is insufficient for normal digestion to occur. The true incidence and diagnosis of EPI after pancreatectomy has not been fully understood and optimized. The aim of this study was to present incidence and diagnostic criteria for EPI after pancreatectomy for cancer and provide a guide for management and optimal therapy in pancreatectomy patients with cancer.

METHODS

A comprehensive review of the literature with publication dates from 2014 to 2019 was performed. A comprehensive diagnostic and treatment algorithm was then created based on literature review and current treatment options.

RESULTS

In total, 30 studies were included, 19 combined both pancreaticoduodenectomy (PD) and distal pancreatectomy (DP), 9 for central pancreatectomy, and 2 others. EPI was defined subjectively without definitive testing using any of the established diagnostic studies in the majority of studies 23 (76%). Preoperative EPI was calculated to be 11.52%. Most studies assessed exocrine function at least 6 months postoperatively with four studies extending the follow-up period beyond 12 months. EPI diagnosed postoperatively at 1 month (40.27%), 3 months (30.94%), 6 months (36.06%), and 12 months (34.69%). After PD, the median prevalence of postoperative EPI was 43.14%, CP, the median prevalence was 4.85%, DP, median prevalence of postoperative EPI of 11.94%.

CONCLUSION

EPI is a frequent outcome that is often misdiagnosed or under-reported by the patient post-pancreatectomy. Given the increasing overall survival in pancreatectomy patients for cancer, surgeon awareness and assessment is critical to improving patients' overall quality of life.

Implementation of Prehabilitation for Major Abdominal Surgery and Head and Neck Surgery: a Simplified Seven-Day Protocol

PURPOSE

The aim of this prospective trial was to assess the compliance of a prehabilitation protocol on post-operative outcome after major abdominal and head and neck surgery.

METHODS

A single-arm, prospective 7-day intervention trial was approved by our local IRB for patients undergoing major abdominal and head-and-neck (H&N) surgery from 8/2018 to 3/2019. This was a 7-day intervention trial at the time of pre-admission testing to assess compliance for pulmonary, nutritional, and physical activity prior to surgery.

RESULTS

Seventy-six patients were enrolled in this compliance with IS use that was 85%, with a median of 2200 cc (range 1500-2500cc), pre-operative nutritional drink (89.5%), and chlorhexidine gluconate use was 92%. Ambulation/step compliance was only 32 patients (44%), with median steps of 7500 (range 400-15,000). Compared with the non-prehabilitation patients, we found significant improvement in immediate post-operative mobility (OR 0.73, 95% CI 0.46-0.97, p = 0.04), and improvement in prevention of pulmonary morbidity (OR 0.82, 95% CI 0.23-1.18, p = 0.07) was observed in the prehabilitation group. No significant difference in overall infectious complications (18% vs 27%), surgical site infections (14% vs 22%), length of stay (median 6 days vs 6), or readmissions (18% vs 22%).

CONCLUSIONS

A simple 7-day prehabilitation protocol at the time of pre-admission testing is feasible with a high degree of compliance regardless of a patient's disease type, education, or socioeconomic background.

An Improved Staging System for Locally Advanced Pancreatic Cancer: A Critical Need in the Multidisciplinary Era

BACKGROUND

Locally-advanced pancreatic cancer (LAPC) is traditionally considered stage III unresectable disease. Advances in induction systemic therapy regimens, surgical technique, and perioperative care have led to successful resection of an increasing number of these tumors with reasonable perioperative outcomes and disease-free intervals. Certain anatomic characteristics that meet criteria for locally-advanced disease, however, are more likely to result in a successful surgical outcome.

METHODS

A practical and consistent system is needed to communicate such nuance between surgical and nonsurgical oncologists for optimal treatment planning and to improve recording for cancer registries and research studies.

RESULTS

The present study proposes a novel subclassification system for stage III pancreatic cancers based on their pattern of vascular involvement and examines the current evidence for resection in each scenario. Introducing needed detail into the current catch-all stage III categorization will help to direct patient referrals and increase the body of knowledge about the variable presentations of this complex malignancy.

CONCLUSION

This proposed staging revision for LAPC is designed to convey more actionable tumor descriptions for treating oncologists, clinical trial eligibility, and surgical patient selection in the era of effective induction systemic therapy.

Outcomes after Laparoscopic Gastropexy as an Alternative for Paraesophageal Hernia Repair

Background:

Outcomes after laparoscopic gastropexy (LG), performed as an alternative to formal paraesophageal hernia (PEH) repair in patients with giant PEH, have been rarely studied. This manuscript evaluates complications and long-term quality-of-life after LG.

Methods:

An IRB-approved protocol was used to identify patients who underwent LG to alleviate symptoms of acute or chronic gastric obstruction secondary to a paraesophageal hernia. Postoperative outcomes and quality-of-life data were retrospectively collected via chart review and prospectively via phone interview.

Results:

Twenty-six patients underwent LG, with a median age of 76 (52 – 91). Median follow-up was 28 (3 to 55) months. Gastropexy was the chosen intervention due to comorbid conditions (23, 88%), gastric inflammation (2, 8%), or intraoperative instability (1, 4%). Nine (35%) suffered postoperative complications, and 2 (8%) required reoperation. At the time of follow-up, 7 (27%) had died, 3 (11%) could not be reached. Sixteen (62%) completed the follow-up survey. Fourteen (88%) reported symptom resolution. Ten (62%) still required antireflux medication. Median Gastroesophageal Reflux Disease-Health Related Quality of Life score was 4.5 (0 to 19). Fourteen (88%) denied current dietary restrictions. All reported satisfaction with the operation.

Conclusion:

Laparoscopic PEH repair remains the standard of care for the management of giant PEH. However, a subcategory of patients with high operative risk could be candidates for a shorter operative intervention. As our data infers, LG is a reasonable alternative in this patient population. While the continued use of antisecretory medications is sometimes required, LG restores the ability to tolerate full meals without restrictions and results in excellent patient satisfaction.

Outcomes of Esophageal Stent Therapy for the Management of Anastomotic Leaks

BACKGROUND

The purpose of this study was to present the optimal patient selection for esophageal stenting after esophageal resection to investigate possible factors leading to treatment success or treatment failure in these patients.

METHODS

This was a prospective, observational study of patients from January 2005 to May 2019 with an esophageal anastomotic leak that were treated with a self-expandable stent (SES).

RESULTS

A total of 34 patients were treated. All achieved technical success (100%); 33 (97%) achieved clinical success. No patient had to have reoperative surgery based on their leak management. The stenting in-hospital mortality was 0% with 1 patient (2%) with a 90-day mortality from possible leak-related death. Patients had their stents removed with a median of 106 days.

CONCLUSIONS

Stenting for an anastomotic leak after resection offers a safe and effective method of treatment and is successful in the majority of cases. Critical to success is optimal patient selection, adequate leak drainage, and optimal stent selection and placement.

The Landmark Series: Locally Advanced Pancreatic Cancer and Ablative Therapy Options

Locally advanced pancreatic cancer (LAPC) is a challenging disease to treat. There is consensus that systemic chemotherapy should be the first line of therapy for most patients. However, there is no consensus on how to manage those patients who do not have sufficient response to become candidates for resection but also do not have distant progression after weeks or months of systemic therapy. Radiation therapy is the most commonly used and best-studied local ablative therapy. One recent randomized controlled trial (LAP-07) failed to demonstrate an overall survival benefit for conventional chemoradiation therapy after induction chemotherapy versus chemotherapy alone. This study had several limitations, and ongoing studies are re-evaluating the role of chemoradiation after more effective chemotherapy regimens as well as more advanced radiation techniques. In parallel, there has been increasing interest in other thermal and non-thermal methods of ablation. In particular, irreversible electroporation has gained traction for treatment of LAPC, with at least one ongoing randomized controlled trial designed to address its role compared with systemic chemotherapy alone. Multiple preclinical and clinical studies are investigating combinations of local ablation and immunotherapy with the goal of generating immune responses that will meaningfully improve outcomes.

Optimizing the Combination of Immunotherapy and Trans-Arterial Locoregional Therapy for Stages B and C Hepatocellular Cancer

Hepatocellular carcinoma (HCC), the most common primary hepatic malignancy worldwide, is the second leading cause of cancer-related death. Underlying liver dysfunction and advanced stage of disease require treatments to be optimally timed and implemented to minimize hepatic parenchymal damage while maximizing disease response and quality of life. Locoregional therapies (LRTs) such as trans-arterial chemo- and radio-embolization remain effective for intermediate liver-only and advanced HCC disease (i.e., Barcelona-Clinic liver cancer stages B and C) not amendable to primary resection or ablation. Additionally, these minimally invasive interventions have been shown to augment the immune system. This and the recent success of immune-oncologic treatments for HCC have generated interest in applying these therapies in combination with such locoregional interventions to improve patient outcomes and response rates. This report reviews the use of trans-arterial LRTs with immunotherapy for stages B and C HCC, potential biomarkers, and imaging methods for assessing the response and safety of such combinations.

Intraoperative Esophagogastroduodenoscopy During Heller Myotomy: Evaluating Guidelines

BACKGROUND

National guidelines suggest routine intraoperative esophagogastroduodenoscopy (EGD) during laparoscopic Heller myotomy (LHM) to assess for mucosal perforation and myotomy adequacy, but the utility of this is unknown. This study aimed to evaluate the effect of intraoperative EGD on outcomes after LHM.

METHODS

Patients who underwent LHM in a single center were retrospectively identified. Outcomes were compared between patients who did and did not undergo intraoperative EGD.

RESULTS

Sixty-one patients were reviewed: 46 (75%) underwent intraoperative EGD and 15 (25%) did not. Mucosal perforations occurred in 2 (4%) of the EGD group and 3 (20%) of the non-EGD group (p = 0.06). All perforations, regardless of EGD use, were recognized laparoscopically. There were no postoperative leaks. Failed myotomy occurred in 5 (11%) who underwent EGD and 1 (7%) who did not (p = 0.64).

CONCLUSIONS

Because EGD does not appear to improve outcomes after LHM, we emphasize its selective, rather than routine, use.

A phase 1b trial of concurrent immunotherapy and irreversible electroporation in the treatment of locally advanced pancreatic adenocarcinoma

BACKGROUND

Combining immune checkpoint blockade therapy with operative disruptive immunomodulation using irreversible electroporation may overcome the resistance to systemic therapy found in patients with locally advanced, unresectable pancreatic cancer. We describe the safety profile and efficacy of IRE with nivolumab.

METHODS

In the preclinical phase of study, human pancreatic cell lines were cultured with interferon-γ (10 ng/mL) and murine models of pancreatic cancer were treated with irreversible electroporation and programmed death ligand-1 (PD-L1) expression was measured. In this phase 1b clinical trial (NCT03080974), surgical ablative irreversible electroporation was performed followed by nivolumab. The primary end point was dose-limiting toxicity.

RESULTS

Human pancreatic cells express PD-L1 when cultured with interferon-γ: quantitative polymerase chain reaction MiaPaca (15.2 rel. fold ± 0.5; P < .01) and S20-13 (31.0 rel. fold ± 4.4; P < .01). Murine orthotopic tumors treated by irreversible electroporation had an increase in signal intensity score for the expression of PD-L1 in residual tumor (P < .01). Ten patients were included in the safety analysis with a 12-month median follow-up (interquartile range 6.0, 15.8). No dose-limiting toxicities occurred. Seven patients developed grade 3/4 treatment-related adverse events; none required a dose modification of nivolumab; nivolumab-related adverse events occurred in 1 patient. Mean time to progression was 6.3 months (confidence interval 3.5-10.0) with current median overall survival of 18.0 months (confidence interval 9.2-26.8).

CONCLUSION

Irreversible electroporation induces expression of PD-L1 in vitro. Combination therapy with concurrent nivolumab is well tolerated. A multicenter, phase 2 adjuvant trial is underway using irreversible electroporation and nivolumab in patients with locally advanced pancreatic cancer.

An evaluation of emergency general surgery transfers and a call for standardization of practices

BACKGROUND

There is an increasing trend toward regionalization of emergency general surgery, which burdens patients. The absence of a standardized, emergency general surgery transfer algorithm creates the potential for unnecessary transfers. The aim of this study was to evaluate clinical reasoning prompting emergency general surgery transfers and to initiate a discussion for optimal emergency general surgery use.

METHODS

Consecutive emergency general surgery transfers (December 2018 to May 2019) to 2 tertiary centers were prospectively enrolled in an institutional review board-approved protocol. Clinical reasoning prompting transfer was obtained prospectively from the accepting/consulting surgeon. Patient outcomes were used to create an algorithm for emergency general surgery transfer.

RESULTS

Two hundred emergency general surgery transfers (49% admissions, 51% consults) occurred with a median age of 59 (18 to 100) and body mass index of 30 (15 to 75). Insurance status was 25% private, 45% Medicare, 21% Medicaid, and 9% uninsured. Weekend transfers (Friday to Sunday) occurred in 45%, and 57% occurred overnight (6:00 pm to 6:00 am). Surgeon-to-surgeon communication occurred with 22% of admissions. Pretransfer notification occurred with 10% of consults. Common transfer reasons included no surgical coverage (20%), surgeon discomfort (24%), or hospital limitations (36%). A minority (36%) underwent surgery within 24 hours; 54% did not require surgery during the admission. Median length of stay was 6 (1 to 44) days.

CONCLUSION

Conditions prompting emergency general surgery transfers are heterogeneous in this rural state review. There remains an unmet need to standardize emergency general surgery transfer criteria, incorporating patient and hospital factors and surgeon availability. Well-defined requirements for communication with the accepting surgeon may prevent unnecessary transfers and maximize resource allocation.

Primitive neuroectodermal tumor incidence, treatment patterns, and outcome: An analysis of the National Cancer Database

BACKGROUND

Primitive neuroectodermal tumors (PNETs) comprise less than 1% of all sarcomas. The rarity of this disease has resulted in a paucity of information about disease process and management. This study sought to evaluate the incidence, treatment patterns, and outcomes among patients with PNET.

METHODS

The National Cancer Database was queried for diagnoses of PNET between 2004 and 2014. Patients were dichotomized based on tumor type (central [cPNET] vs peripheral [pPNET]). Demographic, tumor, treatment, and outcome variables were analyzed for the entire patient cohort and by type of PNET.

RESULTS

White (86.4%) males (56.6%) represented the majority of patients. The incidence of PNET remained stable over the study period (r²  = 0.0821). A total of 70.7% underwent surgical resection of the primary site, 50.3% received radiation, and 74.7% received systemic chemotherapy. Compared to those with pPNET, patients with cPNET more often received radiation treatment (P < .001), primary tumor resection (P < .001), and experienced increased 90-day mortality (P < .014).

CONCLUSION

cPNET and pPNET are rare and aggressive malignancies that tend to arise in White males. Multimodal treatment including surgery, chemotherapy, and radiation is conventional. Patients with cPNET more often receive radiation and primary tumor resection with increased 90-day mortality.

Impact of Perfusate Glucose Concentration on Perioperative Outcomes in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is a common treatment for peritoneal surface malignancies but no standard carrier solution currently exists for the procedure. This study compared a standard low-dextrose perfusate to a higher-dextrose dialysate that has previously shown favorable impact on perioperative patient outcomes in trauma settings.

MATERIALS AND METHODS

A single-center retrospective study identified patients undergoing CRS/HIPEC from 2008 to 2019 with recorded dextrose concentration of administered perfusate. An institutional shift to a higher-dextrose solution was made in late 2015. Comparisons of preoperative factors, intraoperative and postoperative glucose levels, and postoperative outcomes were made using the chi-square test, Fisher's exact test, Wilcoxon rank sum test, or repeated measures analysis of variance.

RESULTS

There were 97 patients in the study, 73 (75%) in the low-dextrose group and 24 (25%) in the high-dextrose group. There was no significant difference in peak intraoperative blood glucose levels between the 1.5% (mean 230 mg/dL) and the 2.5% group (mean 199 mg/dL, P = 0.15). Daily postoperative glucose values were also not statistically different (repeated measures analysis of variance, P = 0.18). Median length of stay was slightly lower for the high-dextrose group (10 d, interquartile range 8-15) than that for the low-dextrose group (12 d, interquartile range 9-17), but was not statistically significant (P = 0.29). Return of bowel function and resumption of diet were similar between the groups. The high-dextrose group had a lower rate of overall complications (20.8%) than the low-dextrose group (49.3%, P = 0.0143). Ninety-day mortality was equivalent between the two groups (2.7% low-dextrose, 4.2% high-dextrose, P = 1.0).

CONCLUSIONS

Use of 2.5% dextrose-containing perfusate appears safe for CRS/HIPEC operations, does not negatively impact intraoperative or postoperative glucose levels, and may be associated with a decreased risk of complications.

Negative Effects of Transfused Blood Components after Hepatectomy for Metastatic Colorectal Cancer

There has been conflicting evidence regarding negative effects of blood transfusion in oncology patients. This study was undertaken to determine any negative effects of specific blood product transfusion after resection of hepatic colorectal metastases (CRM). Retrospective review of patients undergoing hepatectomy for CRM from 1995 to 2009 at a single institution was performed. Specific attention was paid to the effect of blood transfusion within 30 days of operation on overall survival, disease-free survival (DFS), and complications. To mitigate the bias introduced by complications that require blood transfusion to treat, only nonbleeding complications were considered. Complications were analyzed with univariate and multivariate logistic regression. Survival was analyzed according to Kaplan-Meier and Cox proportional hazards. There were 239 patients included in the study. There were 64 (26.8%) receiving a transfusion of any kind with 25.5 per cent getting red cells (PRBCs), 7.11 per cent getting fresh-frozen plasma, and 3.77 per cent getting platelets. Multivariate analysis revealed only PRBC transfusion to be independently associated with nonbleeding complications (odds ratio, 1.980; 95% confidence interval, 1.094 to 3.582; P = 0.0239). There was no significant adverse effect of transfusion with any product on overall or DFS. PRBC transfusion appears to increase the risk of postoperative complications; thus, strategies to minimize blood use may be warranted.

Cardiac synchronization and arrhythmia during irreversible electroporation

BACKGROUND AND OBJECTIVES

Irreversible electroporation (IRE) is a nonthermal electrical tumor ablative strategy for unresectable tumors. IRE is relatively safe around critical structures but may induce cardiac arrhythmia when its delivery is not synchronized to the cardiac cycle. We performed a systematic literature review to determine rates of arrhythmia when IRE was utilized with or without cardiac synchronization.

METHODS

An online literature search was conducted with additional hand selection of articles. Data were extracted and pooled analyses were performed.

RESULTS

Twelve articles were included in analysis. IRE was performed for 481 patients; 46% hepatic tumors (n = 223), 36% pancreatic lesions (n = 168), and multiple other locations including prostate. Synchronization was performed on 422 patients. Arrhythmias were noted in 3.7% of cases (n = 18/481); cardiac synchronization: 1.2% (n = 5/422) vs unsynchronized: 22.0% (n = 13/59), P < .0001. These events occurred in every organ except the prostate.

CONCLUSIONS

IRE remains a potent technology for unresectable tumors, but arrhythmia is a clinical concern. This literature review confirms that cardiac gating should be used in all cases outside of prostate to prevent this potentially serious adverse event.

Carcinogenetic initiation contributed by EpCAM+ cancer cells in orthotopic HCC models of immunocompetent and athymic mice

PURPOSE

Overexpression of epithelial cell adhesion molecule (EpCAM) correlates with poor prognosis, therapeutic failure and early tumor recurrence in hepatocellular carcinoma (HCC) patients. The tumor microenvironment dictates the fate of tumor-initiating cancer stem cells (CSCs); however, very limited studies were attempted to evaluate CSC tumorigenesis in the liver microenvironment. Here, we have systemically investigated the role of EpCAM+ cancer cells in tumor initiation in orthotopic HCC models.

RESULTS

Control mice and the mice with bland steatosis failed to develop tumors. In the mice with steatohepatitis, EpCAM+ CSCs have shown significantly increased ability in terms of tumor initiation and growth, compared to that with EpCAM- non-CSCs inoculation (p < 0.005). For Hep3B inoculation, EpCAM-High group has shown significantly higher tumor growth compared with EpCAM-Low (p < 0.005). For HepG2 inoculation, both EpCAM-High and EpCAM-Low groups confirmed similar tumor incidence and growth.

METHODS

Diet-induced compromised microenvironments were established to mimic clinical fatty liver and non-alcoholic steatohepatitis (NASH) patients and the tumorigenic capabilities of Hepa1-6 cells were evaluated. CSCs were enriched by spheroid culture and labeled with copGFP for EpCAM+ CSCs and with mCherry for non-CSCs. FACS-sorted cells were inoculated into left liver lobes, and tumor growth was monitored by high-frequency ultrasound. The subpopulations of Hep3B and HepG2 cells in terms of EpCAM-Low and EpCAM-High were evaluated in the orthotopic model of athymic mice.

CONCLUSIONS

NASH microenvironment promotes the EpCAM+ CSCs initiated tumorigenesis in immunocompetent mouse model. Differential EpCAM expression demonstrates distinct tumor biology in athymic mouse models.

Patient Derived Xenografts Expand Human Primary Pancreatic Tumor Tissue Availability for ex vivo Irreversible Electroporation Testing

New methods of tumor ablation have shown exciting efficacy in pre-clinical models but often demonstrate limited success in the clinic. Due to a lack of quality or quantity in primary malignant tissue specimens, therapeutic development and optimization studies are typically conducted on healthy tissue or cell-line derived rodent tumors that don't allow for high resolution modeling of mechanical, chemical, and biological properties. These surrogates do not accurately recapitulate many critical components of the tumor microenvironment that can impact in situ treatment success. Here, we propose utilizing patient-derived xenograft (PDX) models to propagate clinically relevant tumor specimens for the optimization and development of novel tumor ablation modalities. Specimens from three individual pancreatic ductal adenocarcinoma (PDAC) patients were utilized to generate PDX models. This process generated 15-18 tumors that were allowed to expand to 1.5 cm in diameter over the course of 50-70 days. The PDX tumors were morphologically and pathologically identical to primary tumor tissue. Likewise, the PDX tumors were also found to be physiologically superior to other in vitro and ex vivo models based on immortalized cell lines. We utilized the PDX tumors to refine and optimize irreversible electroporation (IRE) treatment parameters. IRE, a novel, non-thermal tumor ablation modality, is being evaluated in a diverse range of cancer clinical trials including pancreatic cancer. The PDX tumors were compared against either Pan02 mouse derived tumors or resected tissue from human PDAC patients. The PDX tumors demonstrated similar changes in electrical conductivity and Joule heating following IRE treatment. Computational modeling revealed a high similarity in the predicted ablation size of the PDX tumors that closely correlate with the data generated with the primary human pancreatic tumor tissue. Gene expression analysis revealed that IRE treatment resulted in an increase in biological pathway signaling associated with interferon gamma signaling, necrosis and mitochondria dysfunction, suggesting potential co-therapy targets. Together, these findings highlight the utility of the PDX system in tumor ablation modeling for IRE and increasing clinical application efficacy. It is also feasible that the use of PDX models will significantly benefit other ablation modality testing beyond IRE.

Safety, Efficacy, and Technical Details of Endoscopic Retrograde Cholangiopancreatography After Irreversible Electroporation for Locally Advanced Pancreatic Cancer

BACKGROUND

Patients undergoing irreversible electroporation (IRE) for locally advanced pancreatic cancer (LAPC) may experience biliary obstruction owing to inflammation generated by tumor ablation. This study assessed the safety, efficacy, and technical details of endoscopic retrograde cholangiopancreatography (ERCP) for biliary decompression after IRE.

METHODS

A single-institution database of patients undergoing IRE for LAPC between 2012 and 2017 was queried for patients requiring post-IRE ERCP. Patients were evaluated along demographic, laboratory, procedural, and outcome measures.

RESULTS

Of 113 patients with LAPC who underwent IRE, 6 (5.3%) required subsequent ERCP for biliary obstruction. A total of 12 ERCPs were performed. Two patients (33%) had duodenal bulb narrowing requiring dilation, and one patient (17%) had a pancreatic head cyst complicating guidewire passage. Biliary cannulation was achieved in all patients in a median time of 30 min. Four patients (67%) underwent sphincterotomy, and 5 (83%) underwent stent placement. Post-procedurally, all showed liver test improvement. None developed pancreatitis. Four patients underwent a 2nd ERCP. All were successful and included stent placement.

CONCLUSIONS

For patients with biliary obstruction after IRE, ERCP with sphincterotomy and stent placement can safely relieve this obstruction. Duodenal dilation and careful guidewire manipulation may be required to maximize technical success in these patients.

Optimal perfusion chemotherapy: A prospective comparison of mitomycin C and oxaliplatin for hyperthermic intraperitoneal chemotherapy in metastatic colon cancer

BACKGROUND

Peritoneal carcinomatosis of colorectal adenocarcinoma (CRC) origin is common and is the second-most frequent cause of death in colorectal cancer. There is survival benefit to surgical resection plus hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with metastatic CRC. However, there remains controversy between oxaliplatin (Oxali) and mitomycin C (MMC), as the agent of choice.

METHODS

A review of our 285 patients prospective HIPEC database from July 2007 to May 2018 identified 48 patients who underwent cytoreductive surgery plus HIPEC with MMC or Oxali. Patients were stratified based on preoperative and postoperative peritoneal cancer indices (PCI). The primary outcomes of survival and progression-free survival were compared.

RESULTS

Type of HIPEC chemotherapy was not found to be predictive of overall survival. Preoperative PCI (P = .04), preoperative response to chemotherapy (P = .0001), and postoperative PCI (P = .05) were predictive for overall survival.

CONCLUSIONS

MMC or Oxali based HIPEC chemotherapy are both safe and effective for the management of peritoneal only metastatic CRC. Both perfusion therapies should be considered with all patients receiving modern induction chemotherapy.

Complications of Jejunostomy Feeding Tubes: A Single Center Experience of 546 Cases

INTRODUCTION

Adequate perioperative nutrition is critical for the success of surgical outcomes. Jejunostomy feeding tube placement may ensure enteral feeding access; however, these types of tubes have had variable reported rates of dysfunction/morbidity. The aim of our study was to report our experience with jejunostomy feeding tube placement and the long-term outcomes following complex foregut surgery.

METHODS

We performed a review of all of our jejunostomy feeding tube placement patients from 1/1/2010 until 7/1/2018. The indication for surgery and primary operation were recorded. All adverse events related to the jejunostomy were recorded during the entire duration of tube access. Social "hassle-factor" issues were also reported, including the number of "jejunostomy-related" phone calls, reinsertion and related placement studies, and readmissions pertaining to jejunostomy-associated complications.

RESULTS

During the study period, 542 primary procedures were performed with secondary jejunostomy placement. Jejunostomy-related adverse events occurred in 22.0% of patients (n = 119/542); 12.0% (n = 65/542) were dislodged tubes, 6.0% (n = 30/542) clogged tubes; 5% (n = 25/542) leaking tubes, and 2.8% (n = 15/542) site infections. Tube dysfunctions initiated 244 reinsertion/placement studies in 107 patients, 20 jejunostomy tube-related readmissions, and 78 phone calls to providers for tube dysfunction. Adverse event rates differed significantly between groups (p < 0.001), with esophagogastric resection adverse event rates of 42.3% versus 19.2% for pancreatic ablations.

DISCUSSION

Jejunostomy feeding tubes resulted in adverse events in less than a third of patients. Patient-related hassle must be communicated preoperatively in order to prevent jejunostomy tube-related morbidity. Optimal early and late jejunostomy feeding optimization varies based on preoperative patient comorbidities, type of operation, and the need for adjuvant oncology therapy.

Post-treatment analysis of irreversible electroporation waveforms delivered to human pancreatic cancer patients

Irreversible electroporation (IRE) is a focal ablation therapy that uses high voltage, short electrical pulses to destroy tumor tissue. The success of treatment directly depends on exposure of the entire tumor to a lethal electric field magnitude. However, this exposure is difficult to predict ahead of time and it is challenging for clinicians to determine optimal treatment parameters. One method clinicians rely upon for the cessation of pulse delivery is to monitor the resistance value of the tissue, as the cells within the tissue will undergo changes during electroporation. This work presents a computational model which incorporates human pancreatic tumor conductivity, and compares predicted and measured output currents from IRE treatments of human patients. The measured currents vary widely from patient to patient, suggesting there may areas of high local conductivity in the treatment area.

Electrical Characterization of Human Biological Tissue for Irreversible Electroporation Treatments

Irreversible electroporation (IRE) is a cancer therapy that uses short, high-voltage electrical pulses to treat tumors. Due to its predominantly non-thermal mechanism and ability to ablate unresectable tumors, IRE has gained popularity in clinical treatments of both liver and pancreatic cancers. Existing computational models use electrical properties of animal tissue that are quantified a priori to predict the area of treatment in three dimensions. However, the changes in the electrical properties of human tissue during IRE treatment are so far unexplored. This work aims to improve models by characterizing the dynamic electrical behavior of human liver and pancreatic tissue. Fresh patient samples of each tissue type, both normal and tumor, were collected and IRE pulses were applied between two parallel metal plates at various voltages. The electrical conductivity was determined from the resistance using simple relations applicable to cylindrical samples. The results indicate that the percent change in conductivity during IRE treatments varies significantly with increasing electric field magnitudes. This percent change versus applied electric field behavior can be fit to a sigmoidal curve, as proposed in prior studies. The generic conductivity data from human patients from this work can be input to computational software using patient-specific geometry, giving clinicians a more accurate and personalized prediction of a given IRE treatment.