勝野 秀稔

BACKGROUND: The da Vinci™ Surgical System, recognized as the leading surgical robotic platform globally, now faces competition from a growing number of new robotic surgical systems. With the expiration of key patents, innovative entrants have emerged, each offering unique features to address limitations and challenges in minimally invasive surgery. The hinotori™ Surgical Robot System (hinotori), developed in Japan and approved for clinical use in November 2022, represents one such entrant. This study demonstrates initial insights into the application of the hinotori in robot-assisted surgeries for patients with rectal neoplasms. METHODS: The present study, conducted at a single institution, retrospectively reviewed 28 patients with rectal neoplasms treated with the hinotori from November 2022 to March 2024. The surgical technique involved placing five ports, including one for an assistant, and performing either total or tumor-specific mesorectal excision using the double bipolar method (DBM). The DBM uses two bipolar instruments depending on the situation, typically Maryland bipolar forceps on the right and Fenestrated bipolar forceps on the left, to allow precise dissection, hemostasis, and lymph node dissection. RESULTS: The study group comprised 28 patients, half of whom were male. The median age was 62 years and the body mass index stood at 22.1 kg/m2. Distribution of clinical stages included eight at stage I, five at stage II, twelve at stage III, and three at stage IV. The majority, 26 patients (92.9%), underwent anterior resection using a double stapling technique. There were no intraoperative complications or conversions to other surgical approaches. The median operative time and cockpit time were 257 and 148 min, respectively. Blood loss was 15 mL. Postoperative complications were infrequent, with only one patient experiencing transient ileus. A median of 18 lymph nodes was retrieved, and no positive surgical margins were identified. CONCLUSIONS: The introduction of the hinotori for rectal neoplasms appears to be safe and feasible, particularly when performed by experienced robotic surgeons. The double bipolar method enabled precise dissection and hemostasis, contributing to minimal blood loss and effective lymph node dissection.

BACKGROUND: Hydrocele of the canal of Nuck (HCN) is a rare disease, and its indications for laparoscopic surgery are not well-established. CASE PRESENTATION: A 53-year-old woman was referred to our hospital due to an uncomfortable thumb-sized inguinal mass. Preoperative computed tomography scan and magnetic resonance imaging revealed a hydrocele extending from the abdominal cavity around the left deep inguinal ring via the inguinal canal to the subcutaneous space. The patient was diagnosed with HCN protruding into the abdominal cavity and extending to the subcutaneous space. Laparoscopy can easily access the hydrocele protruding into the abdominal cavity. Furthermore, laparoscopic hernioplasty can be superior to the anterior approach for females. Hence, laparoscopic surgery was performed. After transecting the round ligament of the uterus, a tense 3-cm hydrocele was dissected with it. In order to approach the hydrocele distal to the deep inguinal ring, the transversalis fascia was incised medially to the inferior epigastric vessels. The subcutaneously connected hydrocele was excised from the incision. Then, the enlarged deep inguinal ring was reinforced using a mesh with the laparoscopic transabdominal preperitoneal approach. The patient was discharged 2 days postoperatively. Laparoscopic resection can be more effective for a hydrocele protruding into the abdominal cavity as it facilitates an easy access to the hydrocele. Moreover, laparoscopic resection of a hydrocele extending from the inguinal canal to the subcutaneous space via a transversalis fascia incision can be safer, with low risk of injury to the inferior epigastric vessels. The incised transversalis fascia and the enlarged deep inguinal ring due to the HCN were simultaneously repaired with the laparoscopic transabdominal preperitoneal repair. There are two reports on laparoscopic resection via a transversalis fascia incision for HCNs located between the inguinal canal and the subcutaneous space, which does not require intraperitoneal hydrocelectomy. However, this is the first report on laparoscopic resection of large HCNs protruding into the abdominal cavity and extending beyond the inguinal canal into the subcutaneous space via intraperitoneal hydrocelectomy and a transversalis fascia incision. CONCLUSIONS: Laparoscopic surgery with transversalis fascia incision can be useful for HCNs extending from the abdominal cavity to the subcutaneous space.

＜文献概要＞はじめに 本邦では,米国で開発されたDa Vinci S Surgical System(以下,Sシステム)が手術支援ロボットシステム(Robot-Assisted Surgical System:RASS)として2009年に初めて製造販売承認され,臨床応用されるようになった.その後,Da Vinci Si Surgical System(以下,Siシステム)が機能,操作性,教育面においてアップグレードされ,さらにDa Vinci Xi Surgical System(以下,Xiシステム)が,システムの小型軽量化に伴い操作性,安全性の向上,器具の多様化などを中心にバージョンアップされた.一方,Intuitive社が取得した多数の特許権により他企業でのRASSの開発は遅れていたが,2019年には特許権の有効期限切れにより各企業が開発を進めている.本邦では,2015年よりシスメックス社とMedicaroid社が共同開発を進めてきたhinotori Surgical Robot System(HSRS)の完成を受け,2020年8月泌尿器科,2022年11月には消化器・産婦人科手術の製造販売承認を得た(図1).現在までにマスタースレーブ型のRASSが製造販売承認されているのはDa Vinci Surgical System(DVSS),HSRS,Hugo Robot-Assisted Surgical System(コヴィディエンジャパン社)である.今後,マスタースレーブ型ではない機種も含め,多くの企業から次々にRASSは開発されてくることが予想される.当院では2008年にSシステムが導入され,胃癌手術を先頭に自費診療においても各外科系診療科が次々とDVSSを使用した手術を積極的に導入してきた(図2).アップグレードされたSiシステム,さらに画期的なバージョンアップがされたXiシステムが製造販売承認後,順に導入された.2018年には12術式の保険収載やDVSSによる手術症例件数が急激に増加したことも受け,機種の変更追加が行われた.さらに2020年にはHSRSが製造販売承認後導入され,現在ではXiシステム3台に加え,HSRSの1台が導入されている(図1,2).現在複数のDVSSを導入する施設は多いが,今後,他企業の開発が進むなかで異なる機種を導入する施設も増加することが予測される.異なる機種を同時に運用することは問題点も出てくる.本稿では,著者らの経験をもとにその問題点とその対策について解説する.

BACKGROUND: Although most duodenal carcinomas are pathological adenocarcinomas, a small number of cases have been reported of adenosquamous carcinoma, characterized by variable combinations of two malignant components: adenocarcinoma and squamous cell carcinoma. However, owing to the small number of cases of non-ampullary duodenal adenosquamous carcinoma, there have been no reported cases of emergency pancreaticoduodenectomy for gastrointestinal hemorrhage due to non-ampullary duodenal adenosquamous carcinoma. CASE PRESENTATION: A 66-year-old Japanese male presented to the referring hospital with a chief complaint of abdominal pain, diarrhea, and dark urine that had persisted for 1 month. The patient was referred to our hospital because of liver dysfunction on a blood examination. Laboratory results of the blood on the day of admission showed that total and direct bilirubin levels (12.0 mg/dl and 9.6 mg/dl) were markedly increased. An endoscopic retrograde biliary drainage tube was inserted for the treatment of obstructive jaundice, and imaging studies were continuously performed. Contrast-enhanced computed tomography and endoscopy revealed an ill-defined lesion involving the second portion of the duodenum, predominantly along the medial wall, and measuring 60 mm in diameter. No metastases were observed by positron emission tomography. Pancreaticoduodenectomy was planned based on the pathological findings of poorly differentiated adenocarcinoma. However, 2 days before the scheduled surgery, the patient experienced hemorrhagic shock with melena. Owing to poor hemostasis after endoscopic treatment and poor control of hemodynamic circulation despite blood transfusion, radiological embolization and hemostasis were attempted but were incomplete. An emergency pancreaticoduodenectomy was performed after embolizing the route from the gastroduodenal artery and pseudoaneurysm area to reduce bleeding. The operation was completed using an anterior approach without Kocherization or tunneling due to the huge tumor. The operation time was 4 h and 32 min, and blood loss was 595 mL The pathological diagnosis was adenosquamous carcinoma. The postoperative course was uneventful with 17 day hospital stay and the patient is currently well, with no signs of recurrence 9 months after surgery. CONCLUSIONS: This report presents an extremely rare case of successful emergency pancreaticoduodenectomy for gastrointestinal hemorrhage caused by non-ampullary duodenal adenosquamous carcinoma.

Inflammatory pseudotumor (IPT) is a rare disease that requires a differential diagnosis from malignancies. We describe a case of hepatic IPT with para-aortic lymphadenopathy, treated with a stepwise strategy of laparoscopic surgery. A 61-year-old woman was referred with a liver lesion. Computed tomography revealed a 13 cm well-defined lesion in segments VII-VI. The patient also had bead-like enlarged lymph nodes from the perihilar to the para-aortic regions. Although percutaneous lymph node biopsy showed no evidence of malignancy, 18 F-fluorodeoxyglucose positron emission tomography revealed accumulation in the lesion and lymph nodes. Lymph nodes were harvested laparoscopically for intraoperative pathological examination. With no evidence of malignancy, laparoscopic liver resection was continuously performed as a diagnostic treatment. The patient was given a pathological diagnosis of IPT and was discharged on the 16th day and is well 2 years after surgery. The minimally invasive laparoscopic approach to diagnostic treatment could be useful with secure advantages.

PURPOSE: To delineate the long-term results of minimally invasive transanal surgery (MITAS) for selected rectal tumors. METHODS: We analyzed data, retrospectively, on consecutive patients who underwent MITAS between 1995 and 2015, to establish the feasibility, excision quality, and perioperative and oncological outcomes of this procedure. RESULTS: MITAS was performed on 243 patients. The final histology included 142 cancers, 47 adenomas, and 52 neuroendocrine tumors (NET G1). A positive margin of 1.6% and 100% en bloc resection were achieved. The mean operative time was 27.4 min. Postoperative morbidity occurred in 7% of patients, with 0% mortality. The median follow-up was 100 months (up to ≥ 5 years or until death in 91.8% of patients). Recurrence developed in 2.9% of the patients. The 10-year overall survival rate was 100% for patients with NET G1 and 80.3% for those with cancer. The 5-year DFS was 100% for patients with Tis cancer, 90.6% for those with T1 cancer, and 87.5% for those with T2 or deeper cancers. MITAS for rectal tumors ≥ 3 cm resulted in perioperative and oncologic outcomes equivalent to those for tumors < 3 cm. CONCLUSION: MITAS is feasible for the local excision (LE) of selected rectal tumors, including tumors ≥ 3 cm. It reduces operative time and secures excision quality and long-term oncological outcomes.

Recurrence of liver cancers after liver resection (LR), such as recurrences of hepatocellular carcinoma and colorectal liver metastases, is often treated with repeat LR (RLR) as the only curative treatment. However, RLR is associated with an increased risk of complications. The indications for the currently emerging laparoscopic LR and its advantages and disadvantages for repeat treatment are still under discussion. Our multi-institutional propensity-score matched analyses of laparoscopic vs. open RLRs for hepatocellular carcinoma showed the feasibility of laparoscopic RLR with comparable short- and long-term outcomes. Small blood loss and low morbidity was observed in selected patients treated using laparoscopic RLR in which total adhesiolysis can be dodged, with speculations that laparoscopic minor repeated LR can minimize functional deterioration of the liver. However, there are several disadvantages, such as easily occurring disorientation and difficulty in repeated wide-range dissection of Glissonian pedicles. Recently emerging small anatomical resection, indocyanine green fluorescence-guided surgery, and robot-assisted surgery are promising tools for the further development of laparoscopic RLR. This review discusses how laparoscopic RLR, as a powerful unique local therapy causing less damage to the residual liver and surrounding structures, could contribute to the outcomes of repeated treatments for cancers and its future perspectives.

BACKGROUND:  Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's tumor, is a benign, non-neoplastic vascular lesion that is characterized by reactive proliferation of papillary endothelial cells associated with a thrombus. These lesions typically develop in the vascular regions of the head and neck, oral cavity, or extremities; however, other organ systems have been affected. IPEH in the gastrointestinal tract is rare, with only a few cases reported to date. Thus, the pathogenesis and clinical features of IPEH in the gastrointestinal tract are not entirely understood. Moreover, the local excision of certain subtypes of IPEH can be curative; this makes timely diagnosis essential. We present the case of a patient with IPEH in the cecum that was discovered while investigating the cause of severe anemia. CASE PRESENTATION: A 29-year-old woman visited a general practitioner (GP) with the complaint of abdominal pain. She was diagnosed with acute appendicitis and was prescribed antibiotics. After treatment, her abdominal pain disappeared. However, she was found to be severely anemic (hemoglobin level, 6.5 g/dl). To determine the cause of her anemia, the GP referred her to our hospital for further examination and treatment. Computed tomography scan revealed cecal wall thickening. Further, a lower gastrointestinal endoscopy revealed a 2-cm raised mass-like lesion in the cecum. This lesion was pathologically identified as an inflammatory granuloma. The cause of her anemia was determined to be bleeding from the lesion in the cecum. She underwent laparoscopic ileocecal resection. Histopathological examination of the surgical specimen revealed a spongy structure comprising many small papillary fibrous tissues lined by a typical monolayer endothelium. Further, immunohistochemical analysis showed that the cells of the endothelium monolayer expressed CD31, CD34. The Ki-67 labeling index was < 1%. Based on these findings, the lesion was identified as an IPEH in the cecum. The patient's postoperative course was uneventful, and there was no evidence of recurrence during the 1.3 years of follow-up. CONCLUSIONS:  IPEH rarely arises within the abdominal cavity. Surgery remains the only treatment for IPEH and is associated with an excellent prognosis and a low recurrence rate. More aggressive lesions such as angiosarcoma should be excluded when considering the histologic diagnoses of IPEH, and expert pathologic review is vital. This is the first report of IPEH occurring in the cecum and represents a novel cause of gastrointestinal bleeding which the clinician should consider when evaluating a patient with atypical or difficult gastrointestinal bleeding sources.

OBJECTIVES: Surgical site infection (SSI) is a problematic complication after stoma closure. The purse string suture (PSS) technique eliminates this problem, but the area takes longer to heal. The present retrospective study was performed to evaluate the usefulness of a vacuum-assisted closure (VAC) system for the promotion of wound healing after stoma closure. METHODS: Consecutive patients undergoing stoma closure with the PSS technique were divided into two groups: those treated with and without use of the VAC system. The volume of dead space and the size of the wound were measured after stoma closure in both groups. The same measurements were performed on days 3 and 7 after closure. The time needed for wound closure was also examined in both groups. Outcomes were also evaluated according to age, body mass index, operative time, bleeding volume, wound consistency, patient satisfaction, perioperative inflammatory response, occurrence of SSI, and hospitalization days. RESULTS: The VAC group comprised 31 patients, and the non-VAC group comprised 34 patients. The volume of dead space on days 3 and 7 after closure was significantly smaller in the VAC group than in the non-VAC group (P=0.006 and P<0.001, respectively). The number of SSIs was significantly lower in the VAC group than in the non-VAC group (P=0.014). CONCLUSION: The dead space volume on days 3 and 7 after stoma closure with PSS significantly decreased by using the VAC system. The incidence of SSI after stoma closure also significantly decreased by using the VAC system.

OBJECTIVES: To determine whether the tongue menthol test, which measures the cold sensation detection threshold (CDT) of the tongue, used before and after oxaliplatin administration is an objective evaluation method for oxaliplatin-induced peripheral neuropathy (OPN). METHODS: The tongue menthol test was administered to patients both before and after undergoing chemotherapy containing oxaliplatin for colorectal cancer. The tongue menthol test was conducted by applying a menthol solution (a selective agonist of transient receptor potential cation channel subfamily M member 8 [TRPM8]) to the tongue and measuring the CDT. RESULTS: The mean CDT before the first dose of oxaliplatin was 0.34% (0.005%-1%; n=38), and the mean CDT after the first dose was 0.32% (0.005%-1%; n=38). The CDT appeared to decrease after the first dose, but this difference was not significant. In patients who received five courses of oxaliplatin, changes in CDT values were compared before and after the five courses. In patients with Neurotoxicity Criteria of Debiopharm (DEB-NTC) grade 2 neuropathy, the pre-oxaliplatin administration CDT was compared between before grade exacerbation and when exacerbation occurred, and was found to decline when grade exacerbation occurred. Moreover, when the CDTs before and after administration were compared before grade exacerbation, there was a significant decrease in CDT after administration (P=0.04). CONCLUSIONS: By performing a menthol test in oxaliplatin-treated patients, it may be possible to objectively predict the exacerbation of peripheral neuropathy at an early stage.

We had reported the novel concept of “caudal approach in laparoscopic liver resection” in 2013. In the first report, the caudal approach of laparoscopic transection–first posterior sectionectomy without prior mobilization of the liver in the left lateral position was described. Thereafter, 10 complex laparoscopic extended posterior sectionectomies with combined resection of the right hepatic vein or diaphragm were performed using the same approach. In the present study, the short-term outcomes of these cases and 42 cases of laparoscopic sectionectomies or hemi-hepatectomies (excluding left lateral sectionectomy) were compared. There was no statistically significant difference between the groups in terms of patients’ backgrounds, diseases for resection, preoperative liver function, tumor number and size, as well as outcomes, operation time, intraoperative blood loss, morbidity, conversion to laparotomy, and post-operative hospital stay. Even complex laparoscopic extended posterior sectionectomy was safely performed using this procedure. This approach has the technical benefits of acquiring a well-opened transection plane between the resected liver fixed to the retroperitoneum and the residual liver sinking to the left with the force of gravity during parenchymal transection, and less bleeding from the right hepatic vein due to its higher position than the inferior vena cava. Furthermore, it has an oncological benefit similar to that of the anterior approach in open liver resection, even in posterior sectionectomy. The detailed procedure and general conceptual benefits of the caudal approach to laparoscopic liver resection for repeated multimodal treatment for hepatocellular carcinoma are described.

Although meta-analyses and systematic reviews have clarified the benefits of robotic surgery, few studies have focused on robotic rectal surgery (RRS) and the use of Endowrist® instruments. Therefore, we evaluated RRS using the double bipolar method (DBM) and compared its short-term outcomes with those of RRS using the single bipolar method (SBM). This study enrolled 157 consecutive patients and all procedures were performed by the same surgeon and recorded through short video clips. We analyzed the patient demographics and short-term clinical outcomes. Although this observational study has several limitations, the console time for total mesorectal excision using the DBM was significantly shorter than that using the SBM. Although the DBM did not demonstrate a specific learning curve, it was a safe and feasible procedure even for patients with advanced disease. Further studies are needed to evaluate the cost-effectiveness of the DBM.

Although meta-analyses and systematic reviews have clarified the benefits of robotic surgery, few studies have focused on robotic rectal surgery (RRS) and the use of Endowrist® instruments. Therefore, we evaluated RRS using the double bipolar method (DBM) and compared its short-term outcomes with those of RRS using the single bipolar method (SBM). This study enrolled 157 consecutive patients and all procedures were performed by the same surgeon and recorded through short video clips. We analyzed the patient demographics and short-term clinical outcomes. Although this observational study has several limitations, the console time for total mesorectal excision using the DBM was significantly shorter than that using the SBM. Although the DBM did not demonstrate a specific learning curve, it was a safe and feasible procedure even for patients with advanced disease. Further studies are needed to evaluate the cost-effectiveness of the DBM.

We had reported the novel concept of "caudal approach in laparoscopic liver resection" in 2013. In the first report, the caudal approach of laparoscopic transection-first posterior sectionectomy without prior mobilization of the liver in the left lateral position was described. Thereafter, 10 complex laparoscopic extended posterior sectionectomies with combined resection of the right hepatic vein or diaphragm were performed using the same approach. In the present study, the short-term outcomes of these cases and 42 cases of laparoscopic sectionectomies or hemi-hepatectomies (excluding left lateral sectionectomy) were compared. There was no statistically significant difference between the groups in terms of patients' backgrounds, diseases for resection, preoperative liver function, tumor number and size, as well as outcomes, operation time, intraoperative blood loss, morbidity, conversion to laparotomy, and post-operative hospital stay. Even complex laparoscopic extended posterior sectionectomy was safely performed using this procedure. This approach has the technical benefits of acquiring a well-opened transection plane between the resected liver fixed to the retroperitoneum and the residual liver sinking to the left with the force of gravity during parenchymal transection, and less bleeding from the right hepatic vein due to its higher position than the inferior vena cava. Furthermore, it has an oncological benefit similar to that of the anterior approach in open liver resection, even in posterior sectionectomy. The detailed procedure and general conceptual benefits of the caudal approach to laparoscopic liver resection for repeated multimodal treatment for hepatocellular carcinoma are described.

Obesity has been considered a risk factor for postoperative complications following colorectal cancer surgery. However, the usefulness of a combination of intracorporeal anastomosis and preoperative weight reduction for severely obese patients with colon cancer remains unclear. A 66-year-old man with a body mass index (BMI) of 43 kg/m2 presented with abdominal pain and iron deficiency anemia. Colonoscopy and computed tomography revealed advanced ascending colon cancer with regional lymph node metastasis and excessive abdominal fat. Preoperative diet-induced weight reduction was performed for severe obesity, which decreased his BMI to 39.7 kg/m2 after 1 month. Thereafter, curative resection was performed using intracorporeal anastomosis for reconstruction to achieve minimal colon and mesentery mobilization and a shorter incision. The patient was discharged from the hospital without complications. Laparoscopic right hemicolectomy combining intracorporeal anastomosis and preoperative weight reduction was extremely useful in the current patient with severe obesity and ascending colon cancer.

Enteroceles and rectoceles are often identified as the cause of a vaginal mass and pelvic discomfort. The combination of a rectocele and an enterocele as pelvic organ prolapses is not infrequent; however, there are few reports on possible simultaneous treatments of these two conditions. We report a new and simple procedure for repairing an enterocele during a transvaginal anterior levatorplasty with posterior colporrhaphy for a rectocele repair. This technique involves making an excision in the peritoneal sac, with high ligation, and attaching the uterine cervix and/or cardinal ligament to the upper most part of the approximation of the levator muscles, to reinforce and lift the deep peritoneal sac. This procedure allows for transvaginal repair of both an enterocele and a rectocele. The enterocele is visualized by applying barium to the posterior vaginal wall during defecography.

PURPOSE: The published data on the outcomes of an operative repair for stoma prolapse are limited. This study aimed to clarify the long-term outcomes of stapler repair with anastomosis for stoma prolapse. METHODS: Twenty-four patients (15 men, median age 64 years, range 33-88 years) undergoing 25 stapler repairs with anastomosis were prospectively registered, and their medical records were retrospectively reviewed. RESULTS: The median length of prolapse was 10 cm (range 5-22). Stoma prolapse repair was performed by means of 16 loop colostomies, four end colostomies, three loop ileostomies, and one end ileostomy. A stapler was used 4.6 times on average (range 4-8). The average operative time and bleeding were 40.8 (range 15-75) min and 40 (range 0-214) mL, respectively. No mortality and morbidity were observed after surgery. A recurrence of stoma prolapse was reported in only one of 25 repairs (4%) at the proximal limb of loop ileostomy during a median follow-up period of 1 year (range 1-120 months). However, a new stoma prolapsed in one untreated limb of loop stoma. CONCLUSIONS: Stapler repair with anastomosis is a safe and minimally invasive treatment option for stoma prolapse with a low recurrence. However, the effectiveness of reparing stoma prolapse on the proximal limb of loop ileostomy might be limited.