Learning curve of robotic rectal surgery using risk-adjusted cumulative summation: a 5-year institutional experience.

PURPOSE: Outline learning phases of robot-assisted laparoscopic surgery for rectal cancer and compare surgical and clinical outcomes between each phase of robot-assisted laparoscopic surgery and the mastery phase of conventional laparoscopic surgery. METHODS: From 2015 to 2020, 210 patients underwent rectal cancer surgery at Sendai Medical Center. We performed conventional laparoscopic surgery in 110 patients and, laparoscopic surgery in 100 patients. The learning curve was evaluated using the cumulative summation method, risk-adjusted cumulative summation method, and logistic regression analysis. RESULTS: The risk-adjusted cumulative summation learning curve was divided into three phases: phase 1 (cases 1-48), phase 2 (cases 49-80), and phase 3 (cases 81-100). Duration of hospital stay (13.1 days vs. 18.0 days, respectively; p = 0.016) and surgery (209.1 min vs. 249.5 min, respectively; p = 0.045) were significantly shorter in phase 3 of the robot-assisted laparoscopic surgery group than in the conventional laparoscopic surgery group. Blood loss volume was significantly lower in phase 1 of the robot-assisted laparoscopic surgery group than in the conventional laparoscopic surgery group (17.7 ml vs. 79.7 ml, respectively; p = 0.036). The International Prostate Symptom Score was significantly lower in the robot-assisted laparoscopic surgery group (p = 0.0131). CONCLUSIONS: Robot-assisted laparoscopic surgery for rectal cancer was safe and demonstrated better surgical and clinical outcomes, including a shorter hospital stay, less blood loss, and a shorter surgical duration, than conventional laparoscopic surgery. After experience with at least 80 cases, tactile familiarity can be acquired from visual information only (visual haptic feedback). CLINICAL TRIAL REGISTRATION: UMIN reference no. UMIN000019857.

Evaluating the efficacy of post-operative chemotherapy after curative resection of stage IV gastric cancer with synchronous oligo metastasis: a multicenter retrospective study.

BACKGROUND: Surgical resection of oligo-metastasis in gastric cancer (GC) is weakly recommended for patients without other incurable factors in the Japanese GC Treatment Guidelines. While post-operative chemotherapy is the standard treatment in patients with stage II or III GC, its efficacy for resected stage IV GC is unclear. This study aimed to evaluate the efficacy of post-operative chemotherapy after curative resection of GC with oligo-metastasis. METHODS: We retrospectively reviewed the medical records of patients with GC who were diagnosed with synchronous oligo-metastasis at 20 institutions in Japan between 2007 and 2012. The selection criteria were: adenocarcinoma, stage IV with oligo-metastasis at liver or lymph node without other distant metastasis, curative resection including synchronous oligo-metastasis, and no prior treatment of GC before surgery. RESULTS: A total of 110 patients were collected. Of the 94 eligible patients, 84 underwent gastrectomy with surgical resection of oligo-metastasis (39 [41%] liver metastasis and 55, [59%] distant lymph node metastasis), followed by post-operative chemotherapy with S-1 (S1: n = 55), S1 plus cisplatin (CS: n = 22), or Others (n = 7). Moreover, 10 patients did not receive post-operative chemotherapy (Non-Cx). The median overall survival (OS) was 35.2 and 11.1 months in the post-operative chemotherapy and Non-Cx groups (hazard ratio, 3.56; 95% confidence interval, 1.74-7.30; p < 0.001), respectively. In multivariable analysis, Non-Cx and age over 70 years were identified as poor prognostic factors for OS (p < 0.05). CONCLUSIONS: Curative resection followed by post-operative chemotherapy in patients with GC with synchronous oligo-metastasis showed favorable survival.

Potential urinary function benefits of initial robotic surgery for rectal cancer in the introductory phase.

We aimed to evaluate the advantages and disadvantages of initial robotic surgery for rectal cancer in the introduction phase. This study retrospectively evaluated patients who underwent initial robotic surgery (n = 36) vs. patients who underwent conventional laparoscopic surgery (n = 95) for rectal cancer. We compared the clinical and pathological characteristics of patients using a propensity score analysis and clarified short-term outcomes, urinary function, and sexual function at the time of robotic surgery introduction. The mean surgical duration was longer in the robot-assisted laparoscopy group compared with the conventional laparoscopy group (288.4 vs. 245.2 min, respectively; p = 0.051). With lateral pelvic lymph node dissection, no significant difference was observed in surgical duration (508.0 min for robot-assisted laparoscopy vs. 480.4 min for conventional laparoscopy; p = 0.595). The length of postoperative hospital stay was significantly shorter in the robot-assisted laparoscopy group compared with the conventional laparoscopy group (15 days vs. 13.0 days, respectively; p = 0.026). Conversion to open surgery was not necessary in either group. The International Prostate Symptom Score was significantly lower in the robot-assisted laparoscopy group compared with the conventional laparoscopy group. Moderate-to-severe symptoms were more frequently observed in the conventional laparoscopy group compared with the robot-assisted laparoscopy group (p = 0.051). Robotic surgery is safe and could improve functional disorder after rectal cancer surgery in the introduction phase. This may depend on the surgeon's experience in performing robotic surgery and strictly confined criteria in Japan.

Transanal total mesorectal excision and transabdominal robotic surgery for rectal cancer: A retrospective study.

BACKGROUND: Transabdominal robotic surgery and transanal total mesorectal excision (TaTME) are newly introduced strategies for rectal cancer. These procedures might have many advantages in rectal cancer treatment in terms of improving oncological and functional outcomes, especially in cases involving advanced cancer or technical difficulty. In the present study, we aimed to clarify the advantages and disadvantages of transabdominal robotic surgery and laparoscopic TaTME as a hybrid surgery for rectal cancer. MATERIALS AND METHODS: We retrospectively evaluated six patients who underwent hybrid surgery for rectal cancer from August 2018 to April 2020. Both clinical and pathological outcomes were assessed. RESULTS: Two patients showed circumferential margin involvement both before and after neoadjuvant therapy. Three patients were planned to undergo hybrid surgery with intersphincteric resection because of a narrow pelvis. One patient was planned to undergo hybrid surgery for a giant tumor of >10 cm. The median length of hospitalization was 17 days. No patients required conversion to an open procedure. All patients underwent formation of defunctioning ileostomies. Two patients had a stapled anastomosis and four had a hand-sewn coloanal anastomosis. Complications included one case of anastomotic leakage, which was managed conservatively with ultrasound- and computed tomography-guided drainage and antibiotics. Histological analysis revealed that all specimens had a negative radial margin and distal margin. The median number of lymph nodes harvested was 17.5. Two patients showed extensive lymph node metastases, including lateral node metastasis. CONCLUSION: Hybrid surgery was performed safely and may improve oncological outcomes for rectal cancer. This technique has many potential benefits and would be alternative option in multimodal strategies for rectal cancer.

Impact of preoperative chemotherapy as initial treatment for advanced gastric cancer with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) or localized peritoneal metastasis (P1a): a multi-institutional retrospective study.

BACKGROUND: Gastric cancer (GC) patients with peritoneal metastasis are defined as stage IV in the Japanese classification of GC. For patients with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) and/or localized peritoneal metastasis (P1a), gastrectomy followed by S1 monotherapy is one of the most widely accepted therapeutic strategy in Japan. This study investigated the efficacy of preoperative chemotherapy as initial treatment in GC patients with CY1 and/or P1a. METHODS: We retrospectively reviewed GC patients diagnosed with CY1 and/or P1a at 34 institutions in Japan between 2008 and 2012. Selection criteria were: adenocarcinoma, no distant metastasis except CY1 or P1a, and no prior treatment. The subjects were divided into an Initial-Chemotherapy group and an Initial-Surgery group, according to the initial treatment. RESULTS: A total of 824 patients were collected and 713 eligible patients were identified for this study. As the initial treatment, 150 patients received chemotherapy (Initial-Cx), and 563 patients underwent surgery (Initial-Sx). Initial-Cx regimens were cisplatin plus S1/docetaxel plus cisplatin plus S1/others (n = 90/37/23). Both overall survival (OS) and progression-free survival (PFS) were similar between the Initial-Cx and Initial-Sx groups (median OS 24.8 and 24.0 months, HR 1.07, 95% CI 0.87-1.3; median PFS 14.9 and 13.9 months, HR 1.04, 95% CI 0.85-1.27). The 5-year OS rates were 22.3% in the Initial-Cx group and 21.5% in the Initial-Sx group. CONCLUSIONS: Although, the preoperative chemotherapy did not show a survival benefit for GC patients with CY1 and/or P1a, initial-Cx showed favorable survival in patients who converted to P0 and CY0.

Transanal total mesorectal excision of giant villous tumor of the lower rectum with McKittrick-Wheelock syndrome: a case report of a novel surgical approach.

BACKGROUND: McKittrick-Wheelock syndrome (MKWS) is caused by a villous tumor of the rectosigmoid colon with hypersecretion of mucus containing electrolytes. Complete resection of the tumor is needed to cure this disease. Transanal total mesorectal excision (TaTME) is currently a promising treatment for lower rectal tumor because of the reliability of its resection margin especially in bulky tumor. We present this first case report of a TaTME for MKWS with a lower rectal tumor. CASE PRESENTATION: An 81-year-old woman was admitted to our hospital with diarrhea and acute renal failure. Computed tomography and magnetic resonance imaging examinations revealed an 80-mm-sized enhanced tumor located in her lower rectum without lymph node swelling and distant metastasis. A giant villous tumor secreting mucus was seen in the lower rectum to the anal canal during colonoscopy. The result of tumor biopsy was adenocarcinoma. To preserve the anal function and ensure distal margin, we chose TaTME for curative resection. After improving the electrolyte imbalance, TaTME was performed successfully and R0 resection was achieved. There was no sign of recurrence or electrolyte depletion for 1 year after the surgery. CONCLUSION: TaTME could be a promising surgical approach for giant villous tumor with MKWS in the lower rectum.

[Problems of adjuvant chemotherapy with S-1 for gastric cancer].

From results of ACTS-GC,postoperative adjuvant chemotherapy,administration of S-1 for one year has become the standard for gastric cancer of Stage II and III except T1. We inspected problems of adjuvant chemotherapy by S-1 by dose rate, an adverse event,and compliance. For the period from July 2006 to December 2008,among 41 cases of stage II/stage III gastric cancer, S-1 was as started as adjuvant therapy by for 28 cases (68.3%). Among 14 cases (63.6%) considered able to complete S-1 treatment for one year, 7 cases (31.8%) had to have their dose reduced or their administration schedule changed. No adverse event of grade 3/4 was found, but cancellation or reduced dose was necessary due to anorexia, malaise, diarrhea, severe skin reaction, and leukopenia resulting from myelosuppression. Thirteen patients took no S-1, and two (4.9%) of them took UFT, while 11 cases (26.8%) became a no-treatment follow-up group for reasons of age, coexisting symptoms and other reasons. The problem in the future is to improve compliance, and to establish a treatment strategy for patients who do not meet administration criteria and for patients for whom continuation of drug administration is impossible.