Identifying Indications for Neoadjuvant Therapy in Cholangiocarcinoma.

The recent Hot Topics section focuses on survival rates for patients with cholangiocarcinoma.

Smoking Status and Survival in Patients With Early-Stage Primary Cutaneous Melanoma.

Importance: While smoking is associated with a decreased incidence of cutaneous melanoma, the association of smoking with melanoma progression and death is not well defined. Objective: To determine the association of smoking with survival in patients with early-stage primary cutaneous melanoma. Design, Setting, and Participants: This cohort study performed a post hoc analysis of data derived from the randomized, multinational first and second Multicenter Selective Lymphadenectomy Trials (MSLT-I and MSLT-II). Participants were accrued for MSLT-I from January 20, 1994, to March 29, 2002; MSLT-II, from December 21, 2004, to March 31, 2014. Median follow-up was 110.0 (IQR, 53.4-120.0) months for MSLT-I and 67.6 (IQR, 25.8-110.2) months for MSLT-II. Patients aged 18 to 75 years with clinical stages I or II melanoma with a Breslow thickness of 1.00 mm or greater or Clark level IV to V and available standard prognostic and smoking data were included. Analyses were performed from October 4, 2022, to March 31, 2023. Exposure: Current, former, and never smoking. Main Outcomes and Measures: Melanoma-specific survival of patients with current, former, and never smoking status was assessed for the entire cohort and for nodal observation and among subgroups with sentinel lymph node biopsy (SLNB)-negative and SLNB-positive findings. Results: Of 6279 included patients, 3635 (57.9%) were men, and mean (SD) age was 52.7 (13.4) years. The most common tumor location was an extremity (2743 [43.7%]), and mean (SD) Breslow thickness was 2.44 (2.06) mm. Smoking status included 1077 (17.2%) current, 1694 (27.0%) former, and 3508 (55.9%) never. Median follow-up was 78.4 (IQR, 30.5-119.6) months. Current smoking was associated with male sex, younger age, trunk site, thicker tumors, tumor ulceration, and SLNB positivity. Current smoking was associated with a greater risk of melanoma-associated death by multivariable analysis for the entire study (hazard ratio [HR], 1.48 [95% CI, 1.26-1.75]; P < .001). Former smoking was not. The increased risk of melanoma-specific mortality associated with current smoking was greatest for patients with SLNB-negative melanoma (HR, 1.85 [95% CI, 1.35-2.52]; P < .001), but also present for patients with SLNB-positive melanoma (HR, 1.29 [95% CI, 1.04-1.59]; P = .02) and nodal observation (HR, 1.68 [95% CI, 1.09-2.61]; P = .02). Smoking at least 20 cigarettes/d doubled the risk of death due to melanoma for patients with SLNB-negative disease (HR, 2.06 [95% CI, 1.36-3.13]; P < .001). Conclusions and Relevance: The findings of this cohort study suggest that patients with clinical stage I and II melanoma who smoked had a significantly increased risk of death due to melanoma. Smoking status should be assessed at time of melanoma diagnosis and may be considered a risk factor for disease progression.

Machine Learning to Predict Fascial Dehiscence after Exploratory Laparotomy Surgery.

BACKGROUND: Fascial dehiscence following exploratory laparotomy is associated with significant morbidity and increased mortality. Previously published risk prediction models for fascial dehiscence are dated and limit a surgeon's ability to perform reliable risk assessment intraoperatively. We sought to determine if machine learning can predict fascial dehiscence after exploratory laparotomy. MATERIALS AND METHODS: A retrospective cohort study was conducted of 93,024 patients undergoing exploratory laparotomy from the 2011-2018 ACS NSQIP data files. Data were divided into training (2011-2016, n = 69,969) and temporal validation (2017-2018, n = 23,055) cohorts. A clinical decision support tool was developed using the model generated via machine learning techniques. RESULTS: 1,332 (1.9%) patients in the training cohort and 390 (1.7%) patients in the temporal validation cohort developed fascial dehiscence. The area under the receiver operating characteristic curve was 0.69 (95% CI 0.66 to 0.72) in the validation cohort. Model predictions demonstrated excellent probability calibration. Decision curve analysis calculates net clinical benefit within a threshold range of 0.8%-4.5%. Operative time, surgical site and deep space infections, and body mass index were among the most important features for model predictions. Finally, operative time, sodium level, and hematocrit demonstrated non-linear relationships with predicted risk. CONCLUSION: A clinical decision support tool for predicting fascial dehiscence after exploratory laparotomy was created and validated on a contemporary, national patient cohort using machine learning. The tool calculates net clinical benefit and can be used at the point of care. Some identified risk factor relationships were found to be complex and non-linear, highlighting the ability of some machine learning applications to capture nuanced, patient-specific risk profiles.

Evaluation of disparity in care for perforated appendicitis in a universal healthcare system.

PURPOSE: Racial and socioeconomic disparities have been reported in the management of appendicitis. Perforated appendicitis (PA) is used as an index for barriers to care due to delays in treatment. This study evaluates the effect of racial and socioeconomic differences on the likelihood of PA in a universally insured national healthcare system. METHODS: A retrospective review of pediatric patients enrolled in TRICARE who underwent appendectomy during a 5-year period was performed. Logistic regression was used to examine the association between ethnicity, age, gender, parent, or guardian marital status and deployment status of the active duty parent, type of facility, and type of admission with the odds of perforated appendicitis. RESULTS: A total of 3124 children met inclusion criteria. One-third of children carried the diagnosis of PA. Increased odds of PA was associated with younger age of patient among children of military personnel with enlisted ranks and senior officer ranks. CONCLUSION: In a universal healthcare system, no disparities across race with regard to presentation of appendicitis were identified. Increased odds of perforated appendicitis were observed in younger patients, but this was demonstrated in families of both high and low socioeconomic status. Universal coverage does appear to eliminate some barriers to healthcare.

Larger-Caliber Alternative Devices for Decompression of Tension Hemopneumothorax in the Setting of Hemorrhagic Shock.

BACKGROUND: The 14-gauge (14G) angiocatheter (AC) has an unacceptably high failure rate in treatment of tension pneumothorax (tPTX). Little is known regarding the interplay among hemorrhage, hemothorax (HTX), and tPTX. We hypothesized that increased hemorrhage predisposes tension physiology and that needle decompression fails more often with increased HTX. METHODS: This is a planned secondary analysis of data from our recent comparison of 14G AC with 10-gauge (10G) AC, modified 14G Veress needle, and 3mm laparoscopic trocar conducted in a positive pressure ventilation tension hemopneumothorax model using anesthetized swine. Susceptibility to tension physiology was extrapolated from volume of carbon dioxide (CO2) instilled and time required to induce 50% reduction in cardiac output. Failures to rescue and recover were compared between the 10% and 20% estimated blood volume (EBV) HTX groups and across devices. RESULTS: A total of 196 tension hemopneumothorax events were evaluated. No differences were noted in the volume of CO2 instilled nor time to tension physiology. HTX with 10% EBV had fewer failures compared with 20% HTX (7% versus 23%; p = .002). For larger-caliber devices, there was no difference between HTX groups, whereas smaller-caliber devices had more failures and longer time to rescue with increased HTX volume as well as increased variability in times to rescue in both HTX volume groups. CONCLUSION: Increased HTX volume did not predispose tension physiology; however, smaller-caliber devices were associated with more failures and longer times to rescue in 20% HTX as compared with 10% HTX. Use of larger devices for decompression has benefit and further study with more profound hemorrhage and HTX and spontaneous breathing models is warranted.

The Surgical Experience Aboard USNS COMFORT (T-AH-20) during Operation Continuing Promise 2015.

In 2015, the United States Navy hospital ship (USNS) COMFORT, deployed to 11 Caribbean and Latin American countries over a six-month period to provide humanitarian civic assistance. Personnel from the United States Navy and multiple nongovernmental organizations collaborated to offer surgical and medical care. Data from past deployments aid in planning for future missions by prioritizing finite resources and maximizing care. The data analyzed included all patients evaluated and treated by the Directorate of Surgical Services of the USNS COMFORT between April and September 2015. Comparative and descriptive statistics were performed to analyze patient demographics, surgical subspecialty performing the procedures, types of general and pediatric surgical procedures performed, operative times, and complication rates. Of the 1256 surgical cases performed aboard USNS COMFORT during CP15, 24.8 per cent were general surgery cases, followed by 16 per cent ophthalmology, 10.6 per cent pediatric surgery, 10 per cent plastic surgery, and eight additional specialties with <10 per cent of the cases each. Total operative time was 1253 hours with a total room time of 1896.5 hours. The identified complication rate was 1.99 per cent across all specialties. The USNS COMFORT platform offers the unique capability to provide humanitarian surgical assistance. Reporting these data demonstrate that there is a need for humanitarian assistance and this can be provided safely through the Continuing Promise mission. Future deployments may target resources toward the surgical services with higher volumes, which were general surgery, ophthalmology, pediatric surgery, and plastic surgery.

Bigger is better: Comparison of alternative devices for tension hemopneumothorax and pulseless electrical activity in a Yorkshire swine model.

BACKGROUND: Tension pneumothorax is a cause of potentially preventable death in prehospital and battlefield settings and 14-gauge angiocatheter (14G AC) decompression remains the current treatment standard, despite its high incidence of failure. Traumatic pneumothorax is often associated with hemothorax, but 14G AC has no proven efficacy for associated hemothorax. We sought to compare the 14G AC to three alternative devices for treatment of tension hemopneumothorax (t-H/PTX) in a positive-pressure ventilation swine model. METHODS: Our tension model was modified to incorporate a persistent air leak and pleural blood. Tension physiology was achieved with escalating carbon dioxide insufflation via transdiaphragmatic trocar, and 10% estimated blood volume was instilled into each chest. Intervention was randomized between 14G AC, 10-gauge angiocatheter (10G AC), modified Veress-type needle (mVN), and 3-mm laparoscopic trocar (LT). After recovery, serial tension-induced pulseless electrical activity (PEA) events were induced and decompressed. Success of rescue, time to rescue, and physiologic data were recorded. RESULTS: One hundred ninety-five t-H/PTX and 88 PEA events were conducted in 25 swine. Laparoscopic trocar and 10G AC were more successful and had faster median time to rescue for t-H/PTX compared with 14G AC, whereas mVN performed comparably. Following PEA, 14G AC and mVN succeeded at rescue only 50% and 57% of the time, whereas 10G AC and LT had 100% success at return of spontaneous circulation. Time to successful return of circulation following PEA did not differ between devices; however, there was a noticeable difference in the rate of meaningful hemodynamic recovery following PEA favoring LT and 10G AC. There were no significant injuries noted. CONCLUSIONS: While mVN performed comparably to 14G AC, both have unacceptable failure rates. Ten-gauge AC and LT performed superiorly in both t-H/PTX and PEA. We believe there is now ample evidence supporting replacement of the 14G AC with 10G AC in current treatment recommendations.

Relative device stability of anterior versus axillary needle decompression for tension pneumothorax during casualty movement: Preliminary analysis of a human cadaver model.

BACKGROUND: Tension pneumothorax (tPTX) remains a significant cause of potentially preventable death in military and civilian settings. The current prehospital standard of care for tPTX is immediate decompression with a 14-gauge 8-cm angiocatheter; however, failure rates may be as high as 17% to 60%. Alternative devices, such as 10-gauge angiocatheter, modified Veress needle, and laparoscopic trocar, have shown to be potentially more effective in animal models; however, little is known about the relative insertional safety or mechanical stability during casualty movement. METHODS: Seven soft-embalmed cadavers were intubated and mechanically ventilated. Chest wall thickness was measured at the second intercostal space at the midclavicular line (2MCL) and the fifth intercostal space along the anterior axillary line (5AAL). CO2 insufflation created a PTX, and needle decompression was then performed with a randomized device. Insertional depth was measured between hub and skin before and after simulated casualty transport. Thoracoscopy was used to evaluate for intrapleural placement and/or injury during insertion and after movement. Cadaver demographics, device displacement, device dislodgment, and injuries were recorded. Three decompressions were performed at each site (2MCL/5AAL), totaling 12 events per cadaver. RESULTS: Eighty-four decompressions were performed. Average cadaver age was 59 years, and body mass index was 24 kg/m. The CWT varied between cadavers because of subcutaneous emphysema, but the average was 39 mm at the 2MCL and 31 mm at the 5AAL. Following movement, the 2MCL site was more likely to become dislodged than the 5AAL (67% vs. 17%, p = 0.001). Median displacement also differed between 2MCL and 5AAL (23 vs. 2 mm, p = 0.001). No significant differences were noted in dislodgement or displacement between devices. Five minor lung injuries were noted at the 5AAL position. CONCLUSION: Preliminary results from this human cadaver study suggest the 5AAL position is a more stable and reliable location for thoracic decompression of tPTX during combat casualty transport. LEVEL OF EVIDENCE: Therapeutic study, level III.

Strength and histology of a nanofiber scaffold in rats.

BACKGROUND: Full-thickness soft tissue defects from congenital absence or traumatic loss are difficult to surgically manage. Healing requires cell migration, organization of an extracellular matrix, inflammation, and wound coverage. PLCL (70:30 lactide:caprolactone, Purac), poly(propylene glycol) nanofibrous scaffolds enhance cell infiltration in vitro. This study compares strength and tissue ingrowth of aligned and unaligned nanofibrous scaffolds to absorbable and permanent meshes. We hypothesize that PLCL nanofibrous grafts will provide strength necessary for physiological function while serving as a scaffold to guide native tissue regeneration in vivo. MATERIALS AND METHODS: Abdominal wall defects were created in 126 rats followed by underlay implantation of Vicryl, Gore-Tex, aligned, or unaligned PLCL Nanofiber mesh. Specimens were harvested at 2, 6, and 12 wk for strength testing and 2, 12, and 24 wk for histopathologic evaluation. Specimens were graded for cellular infiltration, multinucleated giant cells (MNG), vascularity, and tissue organization. Mean scores were compared and analyzed with non-parametric testing. RESULTS: The PLCL grafts maintained structural integrity until at least 12 wk and exhibited substantial tissue replacement at 24 wk. At 12 wk, only the aligned PLCL had persistent cellular infiltration of the graft, whereas both aligned and unaligned PLCL grafts showed the presence of MNG. The presence of MNGs decreased in the aligned PLCL graft by 24 wk. CONCLUSIONS: The aligned PLCL nanofiber mesh offers early strength comparable to Gore-Tex but breaks down and is replaced with cellular ingrowth creating a favorable option in management of complex surgical wounds or native soft tissue defects.

The Role of Magnetic Resonance Cholangiopancreatography in the Diagnosis of Choledocholithiasis: Do Benefits Outweigh the Costs?

Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard in evaluation of the biliary tree for choledocholithiasis. Formal indications for magnetic resonance cholangiopancreatography (MRCP) in suspected choledocholithiasis are lacking. Our objective was to determine if MRCP affects management of patients who otherwise would undergo ERCP. A review was conducted of all MRCPs and ERCPs at our institution from 2008 to 2012 with suspected choledocholithiasis. Patients who underwent MRCP and ERCP were compared with those who underwent ERCP alone. Demographic data were collected and notation of whether a post-MRCP ERCP occurred was the primary variable. MRCP was performed in 107 patients for choledocholithiasis. Eighty-eight patients were negative for choledocholithiasis (82%) and 76 were discharged without ERCP (71%). Thirty-one patients received a diagnosis of choledocholithiasis and were referred for ERCP. Of the 19 patients with MRCP-diagnosed common bile duct stones, 95 per cent were confirmed by ERCP (odds ratio 18.0, P < 0.05; agreement 77%, sensitivity 0.76, specificity 0.86, positive predictive value 0.95, negative predictive value 0.50). Length of stay was similar for all groups. A total of 131 patients underwent ERCP without a preprocedural MRCP. Choledocholithiasis was found in 116 patients (92%), whereas 12 patients (9%) had no common bile duct stones and three had an alternate diagnosis. In conclusion, MRCP significantly affected the management of patients who would have undergone ERCP. MRCP did not increase length of stay and contributed to the 95 per cent positivity rate of subsequent ERCPs. These data illustrate the utility of MRCP in suspected choledocholithiasis patients at a low cost with regard to risk and time.