Pathologic Factors Associated with Low Risk of Lymph Node Metastasis in Nonmucinous Adenocarcinoma of the Appendix.

BACKGROUND: Right hemicolectomy (RHC) for nodal staging is recommended for nonmucinous adenocarcinoma of the appendix (NMACA), but it is unclear whether a subgroup of patients at low risk for lymph node (LN) metastasis exists who may be managed with a less extensive resection. PATIENTS AND METHODS: Patients with NMACA without distant metastases who underwent margin negative resection via either RHC or appendectomy/partial colectomy (A/PC) were evaluated from the National Cancer Database (2004-2016). Patients at low risk for LN metastasis were identified. Multivariable survival analysis was performed, and 5-year overall survival (OS) was estimated. RESULTS: Of the 2487 patients included, 652 [26.2%; 95% confidence interval (CI) 24.5-28.0%] had LN metastases. T4 T stage [odds ratio (OR) 4.2, p = 0.032], poorly/undifferentiated histology (OR 2.2, p = 0.004), and lymphovascular invasion (LVI) (OR 4.4, p < 0.001) were associated with LN positivity. One hundred and thirteen patients (4.5%) had tumors at low risk for LN metastasis (T1 T stage, well/moderately differentiated tumors without LVI), and the rate of LN metastasis for this group was 1.8% (95% CI 0.5-6.2%). Conversely, the LN metastasis rate among the 2374 non-low-risk patients was 27.4% (95% CI 25.6-29.2%). Performance of A/PC instead of RHC was associated with a survival disadvantage among all patients (hazards ratio 1.5, p = 0.049), but among the low-risk cohort, 5-year OS did not differ based on resection type (88.3% A/PC versus 92.7% RHC, p = 0.305). CONCLUSIONS: Although relatively uncommon, early, pathologically favorable NMACA is associated with a very low risk of LN metastasis. These select patients may be managed with a less extensive resection without compromising oncologic outcomes.

Diagnosis of Anastomotic Leak.

Anastomotic leaks after colorectal surgery is associated with increased morbidity and mortality. Understanding the impact of anastomotic leaks and their risk factors can help the surgeon avoid any modifiable pitfalls. The diagnosis of an anastomotic leak can be elusive but can be discerned by the patient's global clinical assessment, adjunctive laboratory data and radiological assessment. The use of inflammatory markers such as C-Reactive Protein and Procalcitonin have recently gained traction as harbingers for a leak. A CT scan and/or a water soluble contrast study can further elucidate the location and severity of a leak. Further intervention is then individualized on the spectrum of simple observation with resolution or surgical intervention.

Colorectal Specialization Increases Lymph Node Yield: Evidence from a National Database.

BACKGROUND: Current guidelines recommend the evaluation of at least 12 lymph nodes (LNs) in the pathologic specimen following surgery for colorectal cancer (CRC). We sought to examine the role of colorectal specialization on nodal identification. METHODS: We conducted a retrospective cohort study using SEER-Medicare data to examine the association between colorectal specialization and LN identification following surgery for colon and rectal adenocarcinoma between 2001 and 2009. Our dataset included patients >65 years who underwent surgical resection for CRC. We excluded patients with rectal cancer who had received neoadjuvant therapy. The primary outcome measure was the number of LNs identified in the pathologic specimen following surgery for CRC. Multivariate analysis was used to identify the association between surgical specialization and LN identification in the pathologic specimen. RESULTS: In multivariate analysis, odds of an adequate lymphadenectomy following surgery with a colorectal specialist were 1.32 and 1.41 times greater for colon and rectal cancer, respectively, than following surgery by a general surgeon (p < 0.001). These odds increased to 1.36 and 1.58, respectively, when analysis was limited to board-certified colorectal surgeons. Hospital factors associated with ≥12 LNs identified included high-volume CRC surgery (colon OR 1.84, p < 0.001; rectal OR 1.78, p < 0.001) and NCI-designated Cancer Centers (colon OR 1.75, p < 0.001; rectal OR 1.64; p = 0.007). CONCLUSIONS: Colorectal specialization and, in particular, board-certification in colorectal surgery, is significantly associated with increased LN identification following surgery for colon and rectal adenocarcinoma since the adoption of the 12-LN guideline in 2001.

Failing to Prepare Is Preparing to Fail: A Single-Blinded, Randomized Controlled Trial to Determine the Impact of a Preoperative Instructional Video on the Ability of Residents to Perform Laparoscopic Right Colectomy.

BACKGROUND: Laparoscopic colorectal resection is an index case for advanced skills training, yet many residents struggle to reach proficiency by graduation. Current methods to reduce the learning curve for residents remain expensive, time consuming, and poorly validated. OBJECTIVE: The purpose of this study was to assess the impact of the addition of a preprocedural instructional video to improve the ability of a general surgery resident to perform laparoscopic right colectomy when compared with standard preparation. DESIGN: This was a single-blinded, randomized control study. SETTINGS: Four university-affiliated teaching hospitals were included in the study. PARTICIPANTS: General surgery residents in postgraduation years 2 through 5 participated. INTERVENTION: Residents were randomly assigned to preparation with a narrated instructional video versus standard preparation. MAIN OUTCOME MEASURES: Resident performance, scored by a previously validated global assessment scale, was measured. RESULTS: Fifty-four residents were included. Half (n = 27) were randomly assigned to view the training video and half (n = 27) to standard preparation. There were no differences between groups in terms of training level or previous operative experience or in patient demographics (all p > 0.05). Groups were similar in the percentage of the case completed by residents (p = 0.39) and operative time (p = 0.74). Residents in the video group scored significantly higher in total score (mean: 46.8 vs 42.3; p = 0.002), as well as subsections directly measuring laparoscopic skill (vascular control mean: 11.3 vs 9.7, p < 0.001; mobilization mean: 7.6 vs. 7.0, p = 0.03) and overall performance score (mean: 4.0 vs 3.1; p < 0.001). Statistical significance persisted across training levels. LIMITATIONS: There is potential for Hawthorne effect, and the study is underpowered at the individual postgraduate year level. CONCLUSIONS: The simple addition of a brief, narrated preprocedural video to general surgery resident case preparation significantly increased trainee ability to successfully perform a laparoscopic right colectomy. In an era of shortened hours and less exposure to cases, incorporating a brief but effective instructional video before surgery may improve the learning curve of trainees and ultimately improve safety.

Virtual reality simulator training for laparoscopic colectomy: what metrics have construct validity?

BACKGROUND: Virtual reality simulation for laparoscopic colectomy has been used for training of surgical residents and has been considered as a model for technical skills assessment of board-eligible colorectal surgeons. However, construct validity (the ability to distinguish between skill levels) must be confirmed before widespread implementation. OBJECTIVE: This study was designed to specifically determine which metrics for laparoscopic sigmoid colectomy have evidence of construct validity. DESIGN: General surgeons that had performed fewer than 30 laparoscopic colon resections and laparoscopic colorectal experts (>200 laparoscopic colon resections) performed laparoscopic sigmoid colectomy on the LAP Mentor model. All participants received a 15-minute instructional warm-up and had never used the simulator before the study. Performance was then compared between each group for 21 metrics (procedural, 14; intraoperative errors, 7) to determine specifically which measurements demonstrate construct validity. Performance was compared with the Mann-Whitney U-test (p < 0.05 was significant). RESULTS: Fifty-three surgeons; 29 general surgeons, and 24 colorectal surgeons enrolled in the study. The virtual reality simulators for laparoscopic sigmoid colectomy demonstrated construct validity for 8 of 14 procedural metrics by distinguishing levels of surgical experience (p < 0.05). The most discriminatory procedural metrics (p < 0.01) favoring experts were reduced instrument path length, accuracy of the peritoneal/medial mobilization, and dissection of the inferior mesenteric artery. Intraoperative errors were not discriminatory for most metrics and favored general surgeons for colonic wall injury (general surgeons, 0.7; colorectal surgeons, 3.5; p = 0.045). LIMITATIONS: Individual variability within the general surgeon and colorectal surgeon groups was not accounted for. CONCLUSIONS: The virtual reality simulators for laparoscopic sigmoid colectomy demonstrated construct validity for 8 procedure-specific metrics. However, using virtual reality simulator metrics to detect intraoperative errors did not discriminate between groups. If the virtual reality simulator continues to be used for the technical assessment of trainees and board-eligible surgeons, the evaluation of performance should be limited to procedural metrics.

Outcomes of Colectomy and Proctectomy According to Surgeon Training: General vs Colorectal Surgeons.

BACKGROUND: Colectomies and proctectomies are commonly performed by both general surgeons (GS) and colorectal surgeons (CRS). The aim of our study was to examine the outcomes of elective colectomy, urgent colectomy, and elective proctectomy according to surgeon training. STUDY DESIGN: Data were obtained from the Vizient database for adults who underwent elective colectomy, urgent colectomy, and elective proctectomy from 2020 to 2022. Operations performed in the setting of trauma and patients within the database's highest relative expected mortality risk group were excluded. Outcomes were compared according to surgeon's specialty: GS vs CRS. The primary outcome was in-hospital mortality. The secondary outcome was in-hospital complication rate. Data were analyzed using multivariate logistic regression. RESULTS: Of 149,516 elective colectomies, 75,711 (50.6%) were performed by GS and 73,805 (49.4%) by CRS. Compared with elective colectomies performed by CRS, elective colectomies performed by GS had higher rates of complications (4.9% vs 3.9%, odds ratio [OR] 1.23, 95% CI 1.17 to 1.29, p < 0.01) and mortality (0.5% vs 0.2%, OR 2.06, 95% CI 1.72 to 2.47, p < 0.01). Of 71,718 urgent colectomies, 54,680 (76.2%) were performed by GS, whereas 17,038 (23.8%) were performed by CRS. Compared with urgent colectomies performed by CRS, urgent colectomies performed by GS were associated with higher rates of complications (12.1% vs 10.4%, OR 1.14, 95% CI 1.08 to 1.20, p < 0.01) and mortality (5.1% vs 2.3%, OR 2.08, 95% CI 1.93 to 2.23, p < 0.01). Of 43,749 elective proctectomies, 28,458 (65.0%) were performed by CRS and 15,291 (35.0%) by GS. Compared with proctectomies performed by CRS, those performed by GS were associated with higher rates of complications (5.3% vs 4.4%, OR 1.16, 95% CI 1.06 to 1.27, p < 0.01) and mortality (0.3% vs 0.2%, OR 1.49, 95% CI 1.02 to 2.20, p = 0.04). CONCLUSIONS: In this nationwide study, colectomies and proctectomies performed by CRS were associated with improved outcomes compared with GS. Hospitals without a CRS on staff should consider prioritizing recruiting CRS specialists.

Predicting pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer using 18FDG-PET/CT.

BACKGROUND: Pathologic complete response (pCR) after neoadjuvant chemoradiation (CRT) has been observed in 15-30% of patients with locally advanced rectal cancer (LARC). The objective of this study was to determine whether PET/CT can predict pCR and disease-free survival in patients receiving CRT with LARC. METHODS: This is a retrospective review of patients with EUS-staged T3-T4, N+rectal tumors treated with CRT, who underwent pre/post-treatment PET/CT from 2002-2009. All patients were treated with CRT and surgical resection. Standardized uptake value (SUV) of each tumor was recorded. Logistic regression was used to analyze the association of pre-CRT SUV, post-CRT SUV, %SUV change, and time between CRT and surgery, compared with pCR. Kaplan-Meier estimation evaluated significant predictors of survival. RESULTS: Seventy patients (age 62 years; 42M:28F) with preoperative stage T3 (n=61) and T4 (n=9) underwent pre- and post-CRT PET/CT followed by surgery. The pCR rate was 26%. Median pre-CRT SUV was 10.8, whereas the median post-CRT SUV was 4 (P=0.001). Patients with pCR had a lower median post-CRT SUV compared with those without (2.7 vs. 4.5, P=0.01). Median SUV decrease was 63% (7.5-95.5%) and predicted pCR (P=0.002). Patients with a pCR had a greater time interval between CRT and surgery (median, 58 vs. 50 days) than those without (P=0.02). Patients with post-CRT SUV<4 had a lower recurrence compared with those without (P=0.03). Patients with SUV decrease≥63% had improved overall survival at median follow-up of 40 months than those without (P=0.006). CONCLUSIONS: PET/CT can predict response to CRT in patients with LARC. Posttreatment SUV, %SUV decrease, and greater time from CRT to surgery correlate with pCR. Post-CRT, SUV<4, and SUV decrease≥63% were predictive of recurrence-free and overall survival.

Predictive risk-score model for selection of patients with high-risk stage II colon cancer for adjuvant systemic therapy.

BACKGROUND: Adjuvant systemic therapy is selectively considered for high-risk stage II colon cancer, but which patients benefit most from adjuvant systemic therapy is unclear. METHODS: Patients who underwent resection of stage II colon cancer were identified from the National Cancer Database (2010-2016). Risk-factors for decreased overall survival on multivariable analysis were used to establish a predictive risk-score model for all-cause mortality. After propensity matching within each risk group, 5-year overall survival was estimated based on receipt of adjuvant systemic therapy. RESULTS: Of the 15,241 patients evaluated, 2,857 (18.8%) received adjuvant systemic therapy. Risk factors for decreased overall survival included age >75 (hazard ratio 3.3, P < .001), male sex (hazard ratio 1.2, P < .001), White/Black race (hazard ratio 1.4, P = .020), preoperative carcinoembryonic antigen >3.5 ng/mL (hazard ratio 1.6, P < .001), T4a T-stage (hazard ratio 2.0, P < .001), T4b T-stage (hazard ratio 2.4, P < .001), lymphovascular invasion (hazard ratio 1.2, P = .003), perineural invasion (hazard ratio 1.3, P = .003), and non-R0 proximal/distal resection margins (hazard ratio 1.7, P < .001). An internally validated risk-score model using these factors was developed composed of low-risk (n = 8,489), moderate-risk (n = 4,623), and high-risk (n = 2,129) groups; within each group, 19.9%, 15.7%, and 20.8% of patients, respectively, received adjuvant systemic therapy. After propensity matching, adjuvant systemic therapy was not associated with improved 5-year overall survival for low-risk patients (89.8% vs 88.3%, P = .280), but was for moderate-risk (80.5% vs 70.8%, P < .001), and high-risk (65.2% vs 45.7%, P < .001) patients. CONCLUSION: A predictive risk-score model incorporating patient and tumor factors identifies a high-risk cohort of stage II colon cancer patients who may benefit from adjuvant systemic therapy, although the minority of these patients appear to be receiving treatment.

Overuse and Limited Benefit of Chemotherapy for Stage II Colon Cancer in Young Patients.

BACKGROUND: Few studies have confirmed a benefit for adjuvant chemotherapy (aCTX) in stage II colon cancer. We used the National Cancer Database to explore the use and efficacy of aCTX in patients with both normal-risk (NR) and high-risk (HR) young stage II colon cancer. PATIENTS AND METHODS: We identified patients with stage II colon cancer who underwent colectomy between 2010 and 2015. HR patients included at least: lymphovascular or perineural invasion, < 12 lymph nodes, poor/un-differentiation, T4, or positive margins. Rates of aCTX by age and risk were calculated, and adjusted factors associated with aCTX were identified. Overall survival was estimated using the Kaplan-Meier method and Cox multivariable analyses for patients < 50 years. RESULTS: Among the 81,066 stage II patients who underwent colectomy, 6093 (7.5%) were < 50 years old. Of these, 2669 patients were HR. Thirty percent of NR and almost 60% of HR patients < 50 years received aCTX, compared with 8% and 23% of patients > 50 years (P < .001). In NR patients < 50 years, 35.3% with microsatellite-stable tumors and 18% with microsatellite unstable tumors received aCTX (P < .001), whereas 63.6% and 43.2%, respectively, of HR patients did (P < .001). The most significant multivariable predictors of aCTX were risk status and age. On univariate analysis, there was no survival benefit associated with aCTX in patients < 50 years. Multivariate analysis failed to demonstrate a survival benefit for aCTX for either group (HR, 0.97; P = .84; NR, 0.1.03; P = .90). CONCLUSION: Young patients with HR and NR colon cancer received aCXT more frequently than older patients with no demonstrable survival benefit. This bears further evaluation to avoid the real risks of over-treatment in this increasing population.

Safety of lumbar drains in thoracic aortic operations performed with extracorporeal circulation.

BACKGROUND: The safety of cerebrospinal fluid (CSF) drainage in thoracic aortic surgery using extracorporeal circulation (ECC) with systemic heparinization has not been established. METHODS: Four hundred thirty-two patients had descending thoracic or thoracoabdominal aortic repair between 1993 and 2002. One hundred sixty-two of those patients (age range, 67 +/- 13 years) had repairs performed with ECC, systemic anticoagulation, and lumbar CSF drainage. Repairs performed without CSF drainage, without ECC, or by stent graft (n = 53) were excluded. The CSF catheters were inserted at L3 to L5. Cerebrospinal fluid was drained to maintain pressures of 10 to 12 mm Hg. In the absence of neurologic deficit or coagulopathy, the catheters were capped at 24 hours and removed at 48 hours. Cerebrospinal fluid drainage was continued beyond 24 hours for delayed onset paraparesis. RESULTS: Cerebrospinal fluid drains were used in 135 thoracoabdominal aortic aneurysms (extent I, n = 63; extent II, n = 25; extent III, n = 39; extent IV, n = 8) and 27 descending thoracic aortic repairs (aneurysm, n = 24; traumatic aortic injury, n = 2; aortic coarctation, n = 1). Partial left heart bypass was used in 132 patients, full cardiopulmonary bypass without deep hypothermic circulatory arrest in 5, and cardiopulmonary bypass with adjunctive deep hypothermic circulatory arrest in 25. Time between catheter insertion and anticoagulation was 153 +/- 60 minutes. Heparin achieved an average maximum activated clotting time of 528 +/- 192 seconds. Average ECC time was 114 +/- 77 minutes. Average deep hypothermic circulatory arrest time was 40 +/- 12 minutes. Mortality was 14.1% (23 of 162), and permanent paraplegia was 4.9% (8 of 162). No epidural or spinal hematoma was observed. Six (3.7%) patients had catheter-related complications (temporary abducens nerve palsy [n = 1]; retained catheter fragments [n = 2]; retained catheter fragment and meningitis [n = 1]; isolated meningitis [n = 1]; and spinal headache [n = 1]). CONCLUSIONS: The CSF drainage in thoracic aortic surgery using ECC with full anticoagulation did not result in hemorrhagic complications. The permanent paraplegia rate in this complex patient population consisting of combined distal arch, thoracoabdominal aortic procedures were low, and lumbar CSF catheter-related complications had no permanent sequelae.

Management of malignant colon polyps: current status and controversies.

Colon cancer remains a significant clinical problem worldwide and in the United States it is the third most common cancer diagnosed in men and women. It is generally accepted that most malignant neoplasms of the colon arise from precursor adenomatous polyps. This stepwise progression of normal epithelium to carcinoma, often with intervening dysplasia, occurs as a result of multiple sequential, genetic mutations-some are inherited while others are acquired. Malignant polyps are defined by the presence of cancer cells invading through the muscularis mucosa into the underlying submucosa (T1). They can appear benign endoscopically but the presence of malignant invasion histologically poses a difficult and often controversial clinical scenario. Emphasis should be initially focused on the endoscopic assessment of these lesions. Suitable polyps should be resected en-bloc, if possible, to facilitate thorough evaluation by pathology. In these cases, proper attention must be given to the risks of residual cancer in the bowel wall or in the surrounding lymph nodes. If resection is not feasible endoscopically, then these patients should be referred for surgical resection. This review will discuss the important prognostic features of malignant polyps that will most profoundly affect this risk profile. Additionally, we will discuss effective strategies for their overall management.

Symptomatic rectocele: what are the indications for repair?

BACKGROUND: The surgical indications for symptomatic rectocele are undefined, and surgery has high recurrence rates. We implemented magnetic resonance imaging defecography (MRID) to determine if utilizing strict inclusion criteria for rectocele repair improves outcomes. METHODS: Patients with obstructive defecation syndrome (ODS) who underwent dynamic MRID were evaluated. Indications for surgical repair were defecation requiring manual assistance and the following MRID results: anterior defect >2 cm, incomplete evacuation, and the absence of perineal descent. Primary outcomes were the change in quality of life (QOL) scores and recurrence. RESULTS: From 2006 to 2013, 143 patients who presented with ODS underwent MRID. Seventeen patients met the criteria for repair. Recurrence was low (5.8%) with a median follow-up of 23 months, QOL scores improved from 57.3 to 76.5 (P = .041). CONCLUSIONS: A minority of patients (12%) with ODS met the above criteria for rectocele repair. Patients who underwent repair had a significant improvement in QOL and low recurrence rate.