Surgical quality assessment for the prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for nonmetastatic right colon cancer (PIONEER study).

BACKGROUND: The modified complete mesocolic excision (mCME) procedure for right-sided colon cancer is a tailored approach based on the original complete mesocolic excision (CME) methodology. Limited studies evaluated the safety and feasibility of laparoscopic mCME using objective surgical quality assessments in patients with right colon cancer. The objectives of the PIONEER study were to evaluate oncologic outcomes after laparoscopic mCME and to identify optimal clinically relevant endpoints and values for standardizing laparoscopic right colon cancer surgery based on short-term outcomes of procedures performed by expert laparoscopic surgeons. MATERIALS AND METHODS: This is an ongoing prospective, multi-institutional, single-arm study conducted at five tertiary colorectal cancer centers in South Korea. Study registrants included 250 patients scheduled for laparoscopic mCME with right-sided colon adenocarcinoma (from the appendix to the proximal half of the transverse colon). The primary endpoint was 3-year disease-free survival. Secondary outcomes included 3-year overall survival, incidence of morbidity in the first 4 weeks postoperatively, completeness of mCME, central radicality, and distribution of metastatic lymph nodes. Survival data will be available after the final follow-up date (June 2024). RESULTS: The postoperative complication rate was 12.9%, with a major complication rate of 2.7%. In 87% of patients, central radicality was achieved with dissection at or beyond the level of complete exposure of the superior mesenteric vein. Mesocolic plane resection with an intact mesocolon was achieved in 75.9% of patients, as assessed through photographs. Metastatic lymph node distribution varied by tumor location and extent. Seven optimal clinically relevant endpoints and values were identified based on the analysis of complications in low-risk patients. CONCLUSIONS: Laparoscopic mCME for right-sided colon cancer produced favorable short-term postoperative outcomes. The identified optimal clinically relevant endpoints and values can serve as a reference for evaluating surgical performance of this procedure.

Preoperative computed tomography assessment of circumferential resection margin in retroperitonealized colon cancer predicts disease-free survival.

OBJECTIVES: The aim of this retrospective study was to predict circumferential resection margin (CRM) involvement on preoperative CT, and prognostic impact of CRM assessment by CT (ctCRM) in patients with retroperitonealized colon cancer. METHODS: This study included patients who underwent resection for ascending or descending colon cancer between July 2010 and February 2013. Positive ctCRM was defined as tumor distance to the retromesenteric plane of ≤ 1 mm. The origin of positive CRM was divided into primary tumor or other tumor components including lymph nodes, tumor deposits, or extramural venous invasions. Logistic regression analysis was performed to identify preoperative factors to predict pathologic CRM (pCRM). A Cox proportional hazards model was used in multivariable analysis to determine the preoperative factors affecting disease-free survival (DFS). RESULTS: A total of 274 patients (mean age, 64.0 years ± 11.0 [standard deviation]; 157 men) with retroperitonealized colon cancer were evaluated. Of 274 patients, 67 patients (24.5%) had positive CRM on surgical pathology. The accuracy of preoperative CT in predicting pCRM was 79.6% (218/274). Among preoperative factors, only CRM assessment on CT was independently associated with pCRM (p < 0.001). Positive ctCRM by primary tumor was an independent factor for DFS (HR, 3.362 [1.714-6.593]) and systemic recurrence (HR, 3.715 [1.787-7.724], but not for local recurrence on multivariable analyses. CONCLUSIONS: Preoperative CT can accurately predict pCRM, and positive ctCRM by primary tumor is an independent risk factor for DFS and systemic recurrence, but not for local recurrence in retroperitonealized colon cancer. KEY POINTS: • Preoperative CT can predict pathologic circumferential resection margin (CRM) with approximately 80% of accuracy in patients with retroperitonealized colon cancer. • Positive CRM by a primary tumor on preoperative CT is a poor prognostic factor for disease-free survival and systemic recurrence in patients with retroperitonealized colon cancer. • CRM involvement on CT was not associated with local recurrence in patients with retroperitonealized colon cancer.

Cost analysis of single-incision versus conventional laparoscopic surgery for colon cancer: A propensity score-matching analysis.

BACKGROUND/OBJECTIVE: Although many studies have demonstrated similar perioperative outcomes for single-incision laparoscopic surgery (SILS) and conventional laparoscopic surgery (CLS) for colon cancer, few have directly compared the costs of them. We aimed to compare costs between SILS and CLS for colon cancer. METHODS: We analyzed the clinical outcomes and overall hospital costs of patients who underwent laparoscopic surgery for colon cancer from July 2009 to September 2014 at our institution; 288 were used for analysis after propensity score matching. The total hospital charge, including fees for the operation, anesthesia, preoperative diagnosis, and postoperative management was analyzed. RESULTS: The total hospital charges were similar in both groups ($8770.40 vs. $8352.80, P = 0.099). However, the patients' total hospital bill was higher in the SILS group than in the CLS group ($4184.82 vs. $3735.00, P < 0.001) mainly due to the difference of the cost of access devices. There was no difference in the additional costs associated with readmission due to late complications between the two groups ($2383.08 vs. $2288.33, P = 0.662). Incremental cost-effectiveness ratio for total incision length in 'total hospital charge' and patient's bill and government's bill in 'cost of instruments and supplies' were -$107.08/1 cm, -$109.70/1 cm, and $80.64/1 cm, respectively. CONCLUSION: SILS for colon cancer yielded similar costs as well as perioperative and long-term outcomes compared with CLS. Therefore, SILS can be considered a reasonable treatment option for colon cancer for selective patients.

Intraoperative colonoscopy for the assessment and prevention of anastomotic leakage in low anterior resection for rectal cancer.

PURPOSE: Anastomotic leakage (AL) after stapled anastomosis in rectal cancer surgery is a major concern. Various types of intraoperative anastomotic air leakage tests (ALTs) have been proposed to reduce AL. This study aimed to evaluate the impact of intraoperative colonoscopy (IOC) as an intraoperative ALT in low anterior resection for rectal cancer. METHODS: A total of 1266 patients were retrospectively reviewed. Among them, 215 patients who underwent IOC as an ALT in rectal cancer surgery were identified. IOC was performed after anastomosis to visualize the anastomosis line and to perform an ALT by insufflating the neorectum. Propensity score matching was used to match this group at a 1:1 ratio with 215 patients who underwent ALT with a 250-mL bulb irrigation syringe. Anastomotic defects that were found intraoperatively were resolved either by means of primary repair of the anastomotic defect, if possible, or by performing a preventive diverting ileostomy. RESULTS: The patient characteristics, pathologic outcomes, and operation details showed no significant difference between the two groups. Comparison of the AL rate showed a significant difference between the groups (IOC group without intraoperative leaks vs. non-IOC group without intraoperative leaks 4.3 vs. 11.7%, P = 0.007). The incidence of preventive diverting ileostomy because of a positive ALT was significantly higher in the IOC group than in the non-IOC group (10 vs. 2 cases, P = 0.036). CONCLUSION: IOC can be a valuable method for the assessment of stapled anastomosis and has the additional benefit of directly visualizing the anastomosis line.

Cost-effectiveness of robotic surgery for rectal cancer focusing on short-term outcomes: a propensity score-matching analysis.

Although the total cost of robotic surgery (RS) is known to be higher than that of laparoscopic surgery (LS), the cost-effectiveness of RS has not yet been verified. The aim of the study is to clarify the cost-effectiveness of RS compared with LS for rectal cancer.From January 2007 through December 2011, 311 and 560 patients underwent totally RS and conventional LS for rectal cancer, respectively. A propensity score-matching analysis was performed with a ratio of 1:1 to reduce the possibility of selection bias. Costs and perioperative short-term outcomes in both the groups were compared. Additional costs due to readmission were also analyzed.The characteristics of the patients were not different between the 2 groups. Most perioperative outcomes were not different between the groups except for the operation time. Complications within 30 days of surgery were not significantly different. Total hospital charges and patients' bill were higher in RS than in LS. The total hospital charges for patients who recovered with or without complications were higher in RS than in LS, although their short-term outcomes were similar. In patients with complications, the postoperative course after RS appeared to be milder than that of LS. Total hospital charges for patients who were readmitted due to complications were similar between the groups.RS showed similar short-term outcomes with higher costs than LS. Therefore, cost-effectiveness focusing on short-term perioperative outcomes of RS was not demonstrated.

Long-term oncologic outcomes of robotic low anterior resection for rectal cancer: a comparative study with laparoscopic surgery.

OBJECTIVE: The aim of this study is to evaluate long-term oncologic outcomes of robotic surgery for rectal cancer compared with laparoscopic surgery at a single institution. BACKGROUND: Robotic surgery is regarded as a new modality to surpass the technical limitations of conventional surgery. Short-term outcomes of robotic surgery for rectal cancer were acceptable in previous reports. However, evidence of long-term feasibility and oncologic safety is required. METHODS: Between April 2006 and August 2011, 217 patients who underwent minimally invasive surgery for rectal cancer with stage I-III disease were enrolled prospectively (robot, n = 133; laparoscopy, n = 84). Median follow-up period was 58 months (range, 4-80 months). Perioperative clinicopathologic outcomes, morbidities, 5-year survival rates, prognostic factors, and cost were evaluated. RESULTS: Perioperative clinicopathologic outcomes demonstrated no significant differences except for the conversion rate and length of hospital stay. The 5-year overall survival rate was 92.8% in robotic, and 93.5% in laparoscopic surgical procedures (P = 0.829). The 5-year disease-free survival rate was 81.9% and 78.7%, respectively (P = 0.547). Local recurrence was similar: 2.3% and 1.2% (P = 0.649). According to the univariate analysis, this type of surgical approach was not a prognostic factor for long-term survival. The patient's mean payment for robotic surgery was approximately 2.34 times higher than laparoscopic surgery. CONCLUSIONS: No significant differences were found in the 5-year overall, disease-free survival and local recurrence rates between robotic and laparoscopic surgical procedures. We concluded that robotic surgery for rectal cancer failed to offer any oncologic or clinical benefits as compared with laparoscopy despite an increased cost.

Factors related to preoperative assessment of the circumferential resection margin and the extent of mesorectal invasion by magnetic resonance imaging in rectal cancer: a prospective comparison study.

BACKGROUND: This study was designed to identify factors related to inaccurate prediction of circumferential resection margin (CRM) and the extent of mesorectal invasion (EMI) in T3 tumors by preoperative magnetic resonance imaging (MRI) in rectal cancer. METHODS: A total of 66 patients with rectal cancer were enrolled prospectively in this study. CRM was defined as the distance from the outer tumor margin to the mesorectal fascia, and EMI was defined as the distance from the outer surface of the muscularis propria to the outermost tumor margin. CRM and EMI measurements on MRI were compared with corresponding measurements from whole-mount sections using 1-mm and 5-mm reference values, respectively, as prognostic indicators. The following variables were analyzed for relevance to preoperative staging: tumor distance from the anal verge (lower and middle), tumor location (anterior and posterior), tumor (T) and nodal (N) stage, and the thickness of the perirectal fat (anterior, left, right, and posterior positions). RESULTS: MRI correctly predicted CRM status in 57 of the 66 tumors and EMI status in 51 of the 58 tumors (eight T1 tumors were excluded from EMI analysis). Univariate analysis showed that T3 stage, lymph node involvement, anterior tumor location, and thin perirectal fat thickness at the anterior portion were related to incorrect prediction of CRM. Anterior tumor location and thin perirectal fat thickness at the anterior portion were related to incorrect prediction of EMI. CONCLUSIONS: Preoperative chemoradiation can be accurately guided by preoperative MRI staging, but CRM and EMI in anterior rectal tumor should be interpreted with caution.