Citations

Background: The superficial femoral artery and medial thigh region has been an underused donor site for perforator flaps. This study evaluated perforasomes of the superficial femoral artery and its principal branches to review the clinical applications for locoregional reconstruction. Methods: Twenty-six fresh cadaveric lower extremities were dissected. Perforator size and anatomical course from the superficial femoral artery, descending genicular artery, and saphenous artery branch were documented. Perforators were selectively injected with iodinated contrast to assess vascular territories using computed tomography. A retrospective chart review was conducted on consecutive patients (2014 to 2015). Results: One hundred thirty perforators were mapped in the medial thigh region. Eleven extended medial thigh perforator flaps and 15 hemicircumferential flaps were harvested. The mean distance from the joint line was 16.7 ± 7.3 cm. Perforators arose from the superficial femoral artery (62 percent), saphenous artery branch (23 percent), and descending genicular artery (15 percent). Superficial femoral artery perforators were located around the mid and proximal thigh region (p < 0.001). The median perforasome surface area was 244 cm2, representing 36 percent in hemithigh flaps with preferential filling in the anteromedial region. Proximal perforasomes were the smallest. Perforasome areas based on vessel origin were comparable; however, saphenous artery perforators had a broader perforasome compared with descending genicular (p = 0.01) and superficial femoral artery perforators (p = 0.04). Six clinical case examples were presented for knee, thigh, and lower leg reconstruction. Conclusions: The superficial femoral artery or its branches can provide nontraditional reconstructive perforator flap options in regional reconstruction. They can be simple to harvest using a free-style approach, do not require preoperative imaging, offer a one-stage reconstructive method with low morbidity, and obviate the need for microsurgery or muscle flaps.

Objective To present 6‐month safety and effectiveness data from a multicentre prospective study of aquablation in men with lower urinary tract symptoms (LUTS) attributable to benign prostatic hyperplasia ( BPH ) with prostate volumes between 80 and 150 mL. Methods Between September and December 2017, 101 men with LUTS attributable to BPH were prospectively enrolled at 16 centres in Canada and the USA. Results The mean prostate volume was 107 mL. The mean length of hospital stay after the aquablation procedure was 1.6 days (range: same day to 6 days). The primary safety endpoint (Clavien–Dindo grade 2 or higher or any grade 1 event resulting in persistent disability) at 3 months occurred in 45.5% of men, which met the study design goal of < 65% ( P < 0.001). At 6 months, 22% of the patients had experienced a Clavien–Dindo grade 2, 14% a grade 3 and 5% a grade 4 adverse event. Bleeding complications requiring intervention and/or transfusion were recorded in eight patients prior to discharge and in six patients after discharge. The mean International Prostate Symptom Score improved from 23.2 ± 6.3 at baseline to 6.7 ± 5.1 at 3 months, meeting the study's primary efficacy endpoint goal ( P < 0.001). The maximum urinary flow rate increased from 8.7 to 18.8 mL/s ( P < 0.001) and post‐void residual urine volume decreased from 131 at baseline to 47 at 6 months ( P < 0.0001). At 6 months, prostate‐specific antigen concentration reduced from 7.1 ± 5.9 ng/mL at baseline to 4.0 ± 3.9 ng/mL, a 44% reduction. Conclusions Aquablation is safe and effective in treating men with larger prostates (80–150 mL), without significant increase in procedure or resection time.

AbstractPurposeThe aim of this review was to compare the clinical outcomes of anterior cruciate ligament reconstruction (ACLR) with either meniscal repair or meniscectomy for concomitant meniscal injury. The primary hypothesis was that short‐term clinical outcomes (≤ 2‐year follow‐up) for ACLR concomitant with either meniscal repair or resection would be similar. The secondary hypothesis was that ACLR with meniscal repair would result in better longer term outcomes compared with meniscal resection.MethodsThe authors searched two online databases (EMBASE and MEDLINE) from inception until March 2018 for the literature on ACLR and concurrent meniscal surgery. Two reviewers systematically screened studies in duplicate, independently, and based on a priori criteria. Quality assessment was also performed in duplicate. The Knee injury and Osteoarthritis Outcome Score (KOOS) sub‐scale scores at 2 years post‐operatively were combined in a meta‐analysis of proportions using a random‐effects model.ResultsOf 2566 initial studies, 25 studies satisfied full‐text inclusion criteria. Mean follow‐up was 2.09 years, with a total sample of 37,087 subjects including controls. The meta‐analysis demonstrated equivocal results at 2 years, except for KOOS symptom scores which favoured meniscal resection over repair. Mean KT‐1000 side‐to‐side difference (SSD) scores were 1.51 ± 0.60 mm for meniscal repair, 1.96 ± 0.36 mm for meniscal resection, and 1.58 ± 0.20 for control patients (isolated ACLR). Medial meniscal repair showed decreased anterior knee joint laxity compared to medial meniscal resection (P < 0.001). Patients with meniscal repair had higher rates of re‐operation (13.3% vs 0.8% for meniscal resection, P < 0.001).ConclusionPatients with ACLR combined with meniscal resection demonstrate better symptoms at 2‐year follow‐up compared to patients with ACLR combined with meniscal repair. ACLR combined with meniscal repair results in decreased anterior knee joint laxity with evidence of improved patient‐reported outcomes in the long term, but also higher re‐operation rates.Level of evidenceIII.

606 Background: Between 3-5% of CRC patients have BRCA1/2 pathogenic mutations. This study aims to identify associations between BRCA1 and BRCA2 mutations and clinical characteristics in CRC. Methods: A total of 6396 CRC tumor samples were tested with Next-Generation Sequencing (NGS) on a 592-gene panel, pathogenic or presumed pathogenic variants were counted as mutations (mt). Microsatellite instability (MSI) and tumor mutational burden (TMB) were tested by NGS. Statistical correlations were investigated using ANOVA, Chi-square and t-test. Results: Among tumors sampled, 53% derived from male patients and median age was 60 years. BRCA1 mt were detected in 1.1% (n = 72) of tumors, while BRCA2 in 2.8% (n = 179). BRCA1 mt were more frequent in women (W;65%) than men (M;35%) (p = 0.0019) while no relationship with sex was seen for BRCA2 mt (42% F vs. 58% M). No significant associations with age were noticed. Majority of pathogenic mt in BRCA1 (52%; n = 34) and BRCA2 (62%; n = 103) occurred in MSI-High (MSI-H) cases. MSI-H pts had more frameshift mt in both BRCA1/2 than MSS pts. MSS cases had lower rates of BRCA1 and 2 pathogenic mt (44% and 37%, respectively). Right-sided tumors were significantly associated with BRCA1 (p = 0.0056) and BRCA2 (p < 0.0001) mt in MSI-H cases only. BRCA1/2 mt were associated with higher TMB in all CRCs, including MSI-H and MSS cases (p < 0.001). POLE mt (n = 31) were associated with higher BRCA1/2 mt rates (9.6%, 55% respectively). Among MSS cases with POLE wild-type status, BRCA1 (p = 0.0269) and BRCA2 (p = 0.0151) mt were associated with high TMB and combining both BRCA1/2 mutations led to an even higher TMB (3.6%; p = 0.001). Conclusions: This is the first study to show that BRCA1/2 mutations are more frequent in MSI-H, and independently associated with higher TMB, pathogenic POLE mutations, and right-sided tumors in MSI-H CRCs. Given their relationship with TMB, the presence of BRCA1/2 mutations may be potential predictive biomarkers for checkpoint or PARP inhibitors in CRC, a finding that should be prospectively evaluated.

60 Background: DDR mutations are associated with higher neoantigen load and tumor infiltrating lymphocytes, and are a potential biomarker for immunotherapy. We investigated the association of DDR mutations in gastric (GC), esophageal (EC), and gastroesophageal junction (GEJ) cancers with MSI, PD-L1, and TMB, known predictors for immune checkpoint inhibitors. Methods: 20 DDR mutations were tested by Next-Generation Sequencing (NGS) with a 592-gene panel on a total of 1935 (709 EC; 831 GC; 355 GEJ) cancers. TMB was assessed by NGS, MSI by NGS or fragment analysis, and PD-L1 by IHC (22c3 for CPS or SP142). Results: GC had the highest DDR mutation rate compared to EC and GEJ (27% vs. 20%, p = 0.0005 and 17%, p = 0.0002, respectively). MSI-High (MSI-H) was significantly more common in the DDR mutated cohort (DDR-M) compared to non-mutated cancers (18% vs. 1%; p < 0.0001). TMB-High (≥ 10 mutations/megabase [mt/MB]) was higher in DDR-M (35% vs. 21%; p < 0.0001); in DDR-M cohort, GC had the highest TMB compared to DDR-M EC and GEJ (mean: 13.8 vs. 9.4 vs. 10 mt/MB, respectively; p < 0.0001). DDR mutations were more frequent in the PD-L1 combined positive score (CPS) ≥ 50 group than CPS 0 (42.9% vs. 24%; p = 0.037) and CPS 1-9 (42.9% vs. 20.6%; p = 0.005). ARID1A, ATRX, BRCA2, and PTEN were the most prevalent DDR mutations in MSI-H (87%, 31%, 25%, 24%, respectively); ARID1A, ATRX, BRCA2, and PTEN in TMB-High (47%, 7.7%, 6.7%, 6.8%) and ARID1A, BRCA2, RAD50, and WRN in PD-L1 high (CPS ≥ 10) (48.5% vs. 5.2% vs. 2.5% vs. 3.4%). Conclusions: MSI-H, TMB-high and high PD-L1 expression were significantly more prevalent in the DDR-M cohort compared to non-DDR-mutated cancers, most pronounced in GC. Alterations in ARID1A, ATRX, BRCA2, and PTEN were correlated with MSI-H and TMB-high while ARID1A, BRCA2, RAD50, and WRN were correlated with increased PD-L1 expression. Our findings may help identify patients for tailored immunotherapy approaches in future clinical trials.

505 Background: MSI is a tumor biomarker for immunotherapy efficacy that is closely associated w/deficient MMR, and is also variably associated w/somatic muts of the MMR genes, loss of MMR protein expression by immunohistochemistry (IHC), and high TMB. Germ-line muts (Lynch syndrome/LS) in the 4 MMR genes are recognized to have distinct cancer spectrums/penetrance in LS, yet across all tumors, gene-specific variability in MMR IHC, MMR muts, and TMB is understudied. Methods: Results of TGPs performed by Caris Lifesciences (2015-17) were analyzed in colorectal (CRC), endometrial (EC) and all other cancers/tumors (OT) as: 1) all MSI-H tumors (n = 1057) and 2) all tumors w/ ≥1 mut in an MMR gene (n = 470). A subset of cases had IHC for MMR protein and PD-L1 expression. MSI and TMB were determined by NGS. Results: Characteristics of MSI-H tumors and tumors w/ ≥1 MMR mut are seen in the Table. A single MSH6 mut [F1088fs] in a coding microsatellite represented 31% of all MMR muts detected. F1088fs was found in 58% tumors w/MLH1/PMS2 loss (IHC) but only 25% w/MSH2/MSH6 loss (p < 0.001), was more commonly seen in EC vs CRC/OT (p < 0.001), and was negatively associated w/somatic POLE mut (p = 0.002). Distinct mut signatures in the MMR genes (e.g. GLUàSTOP) were seen in tumors w/POLE muts and DNA repair genes. Conclusions: MSI-H and MMR mutated tumors demonstrate marked gene-specific heterogeneity in IHC patterns, TMBs, and somatic muts that may be relevant to treatment selection, resistance, and response. [Table: see text]

442 Background: Neutrophil to lymphocyte ratio (NLR) has been used as an inflammation-based prognostic marker for various malignancies. The aim of our study was to determine whether NLR can independently predict the overall survival in patients with metastatic gallbladder cancer (GBC). Methods: We identified patients diagnosed with GBC who were treated at Mayo Clinic between the years 2000 and 2016. Patients who had nonmetastatic GBC were excluded along with the patients who did not have data for neutrophils and lymphocytes. Optimal cutoff point for NLR was identified by plotting martingale residuals against NLR and patients were divided into two groups, ≥ 5 or < 5. Demographic, follow-up data and outcomes were collected by retrospective review of electronic medical records. Fisher’s exact test was used to compare categorical variables, while The Mann- Whitney U test was used to compare continuous variables. Kaplan-Meier curves were plotted for NLR ≥ 5 and NLR < 5 and overall survival (OS) between the two groups were compared using log rank test. Multivariate survival analysis was performed using Cox-proportional hazard regression. Results: A total of 231 patients met our inclusion criteria, of which, 138 (60%) had NLR < 5 and 93 (40%) had NLR ≥ 5. Patients with NLR ≥ 5 were more likely to be older and have poor performance score, lower albumin level, higher alkaline phosphatase level, and higher platelet count. There were no significant differences noted in gender, race and administration of chemotherapy between the two groups. In univariate analysis, patients with NLR ≥ 5 at presentation had a significantly worse OS compared to those with NLR < 5 (Median survival: 3.6 vs. 8.8 months, p < 0.001). In multivariate analysis, adjusting for age, ECOG status, albumin, ALP, AST, ALT, bilirubin, platelet count and administration of chemotherapy, NLR of ≥ 5 was associated with a worse OS compared to NLR < 5 (HR: 1.70, 95% CI:1.20 – 2.39. p < 0.05). Conclusions: Our study demonstrates that NLR ≥ 5 is an independent predictor of poor prognosis in patients with metastatic gallbladder cancer.

433 Background: Current staging systems for gallbladder cancer (GBC) are inadequate, as they are based on surgical pathology, and therefore are not relevant for unresectable patients and patients undergoing neoadjuvant chemotherapy. Methods: Patients with a confirmed diagnosis of GBC who were seen at Mayo Clinic between the years 2000 and 2016 were included in this analysis. Data on demographic and tumor characteristics and outcomes were collected by retrospective review of electronic medical records. A model predictive of overall survival was developed using Cox proportional hazard regression analysis. Harrel’s C-statistic was calculated to evaluate the predictive accuracy of the model and compared with the TNM staging system. Results: A total of 523 patients were included in the final analysis, with a median age of diagnosis of 68 years. The median duration of follow up of the entire cohort was 12 months. In multivariate analysis, factors predictive of poorer overall survival were: ages 65-74 years (HR : 1.80, 95% CI: 1.33–2.43) and ages 75+ years (HR: 2.93, 95% CI: 2.12–4.06) compared to age <55 years; tumor size ≥ 5 cm by imaging (HR: 1.24, 95% CI: 1.01–1.55); nodal involvement by imaging (HR:1.61, 95% CI: 1.23–2.10); involvement of distant organs by imaging (HR: 2.85, 95% CI: 2.16–3.75); ECOG performance score of 2 or higher (HR: 1.78, 95% CI: 1.36–2.32) compared to ECOG 0-1; albumin level <3.5 g/dL (HR: 1.40, 95% CI: 1.08–1.81); and alkaline Phosphatase level ≥ 200 IU/L (HR: 1.49, 95% CI: 1.21–1.84). Using these seven predictive factors of survival we created a four-tier staging system. The median survivals of Stages I, II, III and IV created in our novel system were 64, 34, 20 and 7 months with corresponding hazard ratios of 1, 1.5, 2.5 and 8.5 respectively. The C-statistic for this novel staging system was 0.68 compared to C-statistic of 0.69 for the TNM staging system, indicating similar performance in predicting survival. Conclusions: We have created a novel clinically-based staging system for patients with GBC based on nonoperative information at the time of diagnosis which performs on par with the current surgical pathology based TNM staging system.