Laparoscopic Colorectal Surgery with Anatomical Recognition with Artificial Intelligence Assistance for Nerves and Dissection Layers.

BACKGROUND: In digestive tract surgery, dissection of an avascular space consisting of loose connective tissue (LCT) appearing by countertraction improves oncological outcomes and reduces complications.1-3 Kumazu et al.4 described a deep learning approach that automatically segments LCT to help surgeons.4 During left colorectal surgery, lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries cause sexual dysfunction and/or urinary issues.5 As nerve preservation is critical for functional preservation, the AI model Kumazu reported is named Eureka (Anaut Inc., Tokyo, Japan) and was developed to separate nerves automatically. The educative efficacy of intraoperative nerve visualization has been described.6 Artificial intelligence (AI) assisted navigation is expected to aid in the anatomical recognition of nerves and the safe dissection layers surrounding nerves in the future. METHODS: We used Eureka as an educational tool for surgeons' training during laparoscopic colorectal surgery. The laparoscopic system used was Olympus VISERA ELITE3 (Tokyo, Japan). RESULTS: Total mesorectal excision (TME) was safely performed with nerve preservation. No postoperative complications occurred. Automatic segmentation and highlighting of LCT in the dissected layers, lumbar splanchnic, hypogastric, and pelvic visceral nerves (S3, S4), were performed in real time. CONCLUSIONS: In colorectal cancer surgery, the nerves are vital anatomical structures serving as landmarks for dissection. Lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries (S3, S4) cause sexual dysfunction or urinary disorders.5 Nerve preservation is important for functional preservation. AI-assisted navigation methods are noninvasive, user-friendly, and expected to improve in accuracy in the future. They have the potential to develop nerve-guided TME.

Preoperative fluorescent clip marking vs. India ink tattooing for tumor identification during colorectal surgery.

PURPOSE: Identifying tumor location is important in colorectal tumor resection. Preoperative endoscopic India ink marking is a widespread practice, but local injection of ink is an unstable procedure. Although it is often invisible, the ink may be sprayed into the peritoneal cavity and contaminate the surgical field. At our hospital, we introduced fluorescent clip marking (FCM) using the Zeoclip FS®, an endoscopic clip developed using near-infrared fluorescent resin. We tested the usefulness of FCM by retrospectively comparing cases in which FCM was used with cases in which conventional ink marking was used. METHODS: We enrolled 305 patients with colorectal tumors who underwent colorectal surgery after preoperative marking from January 2017 to April 2022. We classified the patients into the FCM group (86 patients) and the India ink tattoo group (219 patients). Endoscopic marking was completed in the FCM group by the day before surgery, and fluorescence was evaluated during surgery with a fluorescent laparoscopic system. Patient backgrounds, marking visibility, adverse effects, and early postoperative results were retrospectively compared between groups. RESULTS: Marking was visually confirmed in 80 patients in the FCM group (93.02%) and in 166 patients in the India ink tattoo group (75.80%) (p = 0.0006). In the group with India ink tattoos, contamination of the surgical field was observed in seven cases (3.20%). No adverse events were observed in the FCM group. CONCLUSION: In colorectal surgery, FCM provides better visibility than the conventional India ink tattooing method and is a simple and safe marking method. CLINICAL TRIAL REGISTRATION: Examination of fluorescence navigation for laparoscopic colorectal cancer surgery. Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf .

Fluorescence angiography vs. direct palpation for bowel viability evaluation with strangulated bowel obstruction.

PURPOSE: In surgery for strangulated bowel obstruction, intestinal blood flow (IBF) is usually evaluated by observing bowel colour, peristalsis, intestinal temperature and arterial pulsations in the mesentery. We investigated whether indocyanine green (ICG) fluorescence angiography (ICG-FA) is an effective alternative to palpation. METHODS: Thirty-eight patients who underwent emergency surgery for strangulated bowel obstruction from January 2017 to April 2021 were divided into two groups: (i) the ICG + group, in which ICG was used during laparoscopic surgery (n = 16), and (ii) the ICG - group, in which palpation without ICG was used during open surgery (n = 22). Starting in July 2019, ICG and laparoscopic surgery were applied in all cases except emergency cases when the fluorescence laparoscope was not ready. Surgical outcomes and patient characteristics were compared. RESULTS: Patient characteristics, the operative duration and postoperative hospitalization duration did not significantly differ between the groups. Bowel resection was performed in 4 cases (25%) among ICG + patients and 11 cases (50%) among ICG - patients. The ratios of pathological findings (ischaemia:mucosal necrosis:transmural necrosis) were 0:2:2 and 1:6:4 in the two groups, respectively. Blood loss was measured with gauze and suction tubes and was 1 (0-5) mL in the ICG + group and 12.5 (0-73) mL in the ICG - group (p = 0.002). Postoperative complications occurred in 1 case (6.3%) in the ICG + group and 9 cases (40.9%) in the ICG - group (p = 0.025). CONCLUSION: Although there were few intestinal resections in the ICG + group, the rate of pathological necrosis tended to be high, and no complications due to ineligibility were noted in the intestinal preservation group. During laparoscopic surgery, ICG-FA is useful as a substitute for palpation and has the potential to improve surgical outcomes. CLINICAL TRIAL REGISTRATION: Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2019-40.

Fluorescence vessel and ureter navigation during laparoscopic lateral lymph node dissection.

BACKGROUND: Lateral lymph node metastasis in lower rectal cancer is considered a local disease in Japan, and guidelines suggest lateral lymph node dissection (LLND). However, laparoscopic procedures are relatively difficult. The ureter and hypogastric fascia must be dissected from the vesicohypogastric fascia to preserve the autonomic nerve and ureter. Additionally, lymph node dissection around the internal iliac artery is complex because many patterns of branching from the internal iliac artery exist. We investigated the utility of fluorescence ureter and vessel navigation using a near-infrared ray fluorescent ureteral catheter (NIRFUC) and indocyanine green (ICG). METHODS: Fourteen patients who underwent laparoscopic LLND using fluorescence navigation were included. Eleven patients had rectal cancer, 1 had anal cancer, and 2 exhibited recurrence of rectal cancer. Eleven patients underwent NIRFUC insertion before surgery. Fluorescence vessel navigation (FVN) was performed with intraoperative ICG injections in 14 patients, with a total of 18 sides. The outcome measures were ureter navigation visibility, detection of the branch form from the internal iliac artery with FVN, differences between the fluorescence findings and anatomy of the internal iliac artery determined after LLND, and the surgical outcome. RESULTS: In all 11 patients, the ureters were clearly identified as fluorescent before dissection around the ureter. FVN revealed the internal iliac, umbilical, and superior vesical arteries in all patients. The branch from the internal iliac artery according to the Adachi classification was revealed on 16 sides (89%). The time from intravenous ICG injection to fluorescence of the internal iliac artery was 38 (17-57) s. The time from intravenous injection to when the vessels were observed as fluorescent was 113 (65-661) s. No ureteral or vessel injuries occurred. CONCLUSIONS: Fluorescence navigation of vessels and the ureter is feasible in laparoscopic LLND and has the potential to increase safety. CLINICAL TRIAL REGISTRATION: Examination of fluorescence navigation for laparoscopic colorectal cancer surgery Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

The impact of S-1 for the patient with lymph nodal metastasis biliary tract cancer as adjuvant chemotherapy: a multicenter database analysis.

INTRODUCTION: Although adjuvant chemotherapy is expected to improve the prognosis for patients with biliary tract cancer after curative resection, there is limited evidence regarding the efficacy and prognostic factors of adjuvant chemotherapy. We investigated the effective subgroups for whom adjuvant chemotherapy with S-1 in biliary tract cancer patients. METHODS: 413 patients who underwent curative resection for biliary tract cancer at our four affiliated hospitals between 2009 and 2019 were included in this study. The association of adjuvant chemotherapy with long-term outcomes in overall and patient subgroups were investigated by univariate and multivariate analyses. RESULTS: Among overall patients, adjuvant chemotherapy with S-1 did not improve disease free survival (p = 0.29) and overall survival (p = 0.83). In the subgroup analysis, adjuvant chemotherapy with S-1 improved both disease-free and overall survival in patients with lymph node metastasis, advanced Stage (III and IV), and microscopic residual tumor. In 135 patients with lymph node metastasis, adjuvant chemotherapy with S-1 was given in 67 patients (50%). In the patients with lymph node metastasis, preoperative bile duct drainage (p = 0.01) and adjuvant chemotherapy (p = 0.04) were independent and significant predictors of disease-free survival, while preoperative bile duct drainage (p = 0.03), tumor differentiation (p = 0.03), and adjuvant chemotherapy (p = 0.03) were independent and significant predictors of overall survival. CONCLUSION: After resection of biliary tract cancer, adjuvant chemotherapy with S-1 appears to benefit those who had lymph node metastasis.

Ureteral navigation using a fluorescent ureteral catheter during laparoscopic colorectal surgery.

BACKGROUND: Ureteral injury is the most common urological complication of pelvic surgery, with a reported incidence during colon resection of 0.3-1.5%. Ureteral stenting is commonly performed preoperatively to prevent ureteral injury. Because tactile sensation is not reliable during laparoscopic surgery, the effect of the ureteral stent is considered limited. Recently, fluorescence imaging has been used in laparoscopic surgery. The Near-Infrared Ray Catheter (NIRC™) fluorescent ureteral catheter (NIRFUC) is a new catheter with built-in NIR fluorescent resin. This pilot study was performed to evaluate the utility of fluorescence ureteral navigation using the NIRFUC during laparoscopic colorectal surgery. METHODS: We evaluated the intraoperative utility of the NIRFUC and the short-term outcomes in 20 patients treated with colorectal surgery at Kawaguchi Municipal Medical Center between February and July 2020. In all, 18 patients with malignant tumors and 2 patients with benign disease, i.e., a sigmoid colovesical fistula, were included. Ten patients developed preoperative intestinal obstruction. One patient experienced preoperative perforation. Nine patients developed preoperative peritumoral abscesses. Laparoscopic surgery was performed with the VISERA ELITE2 system. RESULTS: In all cases, the ureters were very clearly identified as fluorescent without the need for dissection. In all cases, only a moment was required to identify the ureter by fluorescence observation. In all cases, R0 resection was performed. The mean surgical duration was 334 min (161-1014), the mean blood loss was 10 ml (1-500), and the mean postoperative hospital stay was 11 days (8-47). There were no cases of ureteral injury. CONCLUSION: The NIRFUC was very clearly identified as fluorescent in a moment during surgery without dissection around the ureter. Fluorescence ureteral navigation using the NIRFUC may make colorectal surgery easier and facilitate completion of complex minimally invasive surgery, especially during surgery in patients with invasion of the surrounding tissue or a history of pelvic surgery or radiation.

[Intra-Abdominal Desmoid Tumor in a Young Man without Laparotomy History-A Case Report].

During a follow-upstudy after the treatment of T cell lymphoma, a 21-year-old man reported an intra-abdominal mass in his right lower abdomen, which was then confirmed using abdominal CT. Therefore, recurrence was suspected due to his medical history. To perform a biopsy, laparoscopic surgery was scheduled, which located the tumor in the mesentery of the terminal ileum, involving the cecum. For this, laparoscopic ileocecal resection was performed. After 7 days, the patient was discharged without complications. Histopathologically, the mass was diagnosed as a desmoid tumor via immunostaining. It is relatively rare that an intra-abdominal desmoid tumor occurs without risk factors in a young man. We herein report a case of an intra-abdominal desmoid tumor, which was successfully treated using laparoscopic surgery.

[Subcutaneous Metastasis from Rectal Carcinoma after Low Anterior Resection-A Case Report].

A 63-year-old woman was admitted to our hospital owing to advanced rectal carcinoma. The patient underwent laparoscopic lowanterior resectionwith D3 lymph node dissection and partial resection of the uterus. The histopathological diagnosis was fT4bN2M0, fStage Ⅲb. Thus, capecitabine plus oxaliplatin(CapeOX)therapy as adjuvant chemotherapy was scheduled for 6 months. However, after the 4th course of chemotherapy, contrast-enhanced CT revealed multiple metastases of the rectal carcinoma including metastases in the liver, peritoneum, retroperitoneum, and subcutaneous tissue of the left lower back. The patient received palliative treatment and died 8 months after surgery. Only a fewcases of subcutaneous metastasis of rectal carcinoma have been reported. Therefore, we herein report this case with a review of the literature.

[A Case of Synchronous Multiple Colon Carcinoma-A Case Report].

A 67-year-old woman with anemia was referred to us for further study. A colonoscopy exhibited multiple tumors(tub1)in the transverse and sigmoid colon(two regions)and rectum. Contrast-enhanced CT revealed no apparent distant and lymph node metastases. Thus, subtotal colectomy with D3 lymph node dissection was performed. Pathologically, the tumor was diagnosed as pStage Ⅱand pStage 0. After surgery, the patient had no recurrence for 8 months. We herein report a rare case of four synchronous colorectal carcinomas that were successfully treated.

[A Case of Ampullary Region Carcinoma in a Young Woman - A Case Report].

A 19-year-old woman with general fatigue who initially consulted a local hospital was referred to us for further examination of jaundice. Contrast-enhanced CT revealed apparent dilatation of the bile duct. Gastrointestinal endoscopy exhibited a tumor of the papilla of Vater(adenocarcinoma, tub2). Thus, pylorus-preserving pancreatoduodenectomy with D2 lymph node dissection was performed. Pathologically, she was diagnosed with a T3bN1M0, pStage ⅡB tumor. After surgery, the patient underwent adjuvant chemotherapy containing S-1 for 6 months. We herein report a juvenile case of ampullary region carcinoma that was successfully treated.

[Curatively Resected Stage â £Gastric Cancer with Positive Peritoneal Cytology Due to SOX Therapy-A Case Report].

A 70-year-old man with epigastralgia who initially visited a local hospital was referred to us for further examination. Gastrointestinal endoscopy exhibited a type 3 tumor of the stomach from the body to the antrum(adenocarcinoma, por1). Contrast-enhanced CT revealed thickness in the wall of the gastric body with bulky lymph nodes and ascites. Staging laparoscopy showed that the patient was diagnosed with sStage Ⅳ gastric cancer with positive peritoneal cytology. Therefore, SOX therapy was administered. Subsequently, total gastrectomy with D2 lymph node dissection was performed, since the primary tumor and lymph nodes were significantly reduced. Histopathologically, the residual lesion was only observed in the mucosal layer without lymph node metastases. We herein report a case of Stage Ⅳ gastric cancer, which was successfully treated by conversion surgery after SOX therapy.

Transanal Total Mesorectal Excision for Extended Surgery in the Early Stage After Introduction.

BACKGROUND/AIM: The effectiveness of transanal total mesorectal excision (Ta-TME) in extended surgery (ES) has been discussed. This study examined the short-term outcomes of the first 31 patients who underwent Ta-TME after its introduction and verified the safety of Ta-TME in ES in the early stage following its introduction. PATIENTS AND METHODS: Thirty-one consecutive patients who underwent Ta-TME between December 2021 and January 2023 at our institution were included. The indications for Ta-TME were rectal tumors that could be palpated during rectal examination and bulky tumors that were deemed unresectable without Ta-TME. Short-term outcomes were retrospectively compared between patients who underwent normal Ta-TME, (n=27, TME group) and patients who underwent ES beyond TME (n=4, ES group). The data are shown as the median and interquartile range. Statistical analysis was performed with the Mann-Whitney U-test and Fisher's exact test. RESULTS: Total pelvic exenteration (TPE) was performed in the 4th and 8th patients; the 9th patient underwent a combined resection of the right adnexa and urinary bladder wall. The 31st patient underwent a combined resection of the uterus and the right adnexa. The operative time was 353 [285-471] vs. 569 [411-746] min for the TME and ES groups (p=0.039). Blood loss was 8 [5-40] vs. 45 [23-248] ml (p=0.065); postoperative hospital stay was 15 [10-19] vs. 11 [9-15] days (p=0.201); postoperative complications (higher than grade III) were 5 (19%) vs. 0 (p=1.000). Negative CRM was achieved in all cases. CONCLUSION: Ta-TME in ES was as safe as normal Ta-TME in the early stage after its introduction.

The impact of C-reactive protein-albumin-lymphocyte (CALLY) index on the prognosis of patients with distal cholangiocarcinoma following pancreaticoduodenectomy.

Aim: The C-reactive protein (CRP)-albumin-lymphocyte (CALLY) index is a novel inflammation-based biomarker, which has been associated with long-term outcomes in patients with hepatocellular carcinoma. We aimed to investigate whether the CALLY index can predict the prognosis for distal cholangiocarcinoma after pancreaticoduodenectomy. Methods: The study comprised 143 patients who had undergone primary pancreaticoduodenectomy for distal cholangiocarcinoma between 2002 to 2019. The CALLY index was defined as (albumin × lymphocyte)/ (CRP × 104). We investigated the association of CALLY index with disease-free survival and overall survival by univariate and multivariate analyses. Results: Eighty-seven (61%) patients had a preoperative CALLY index <3.5. In multivariate analysis, obstructive jaundice drainage (P < .01), poorly differentiated tumor (P < .01), and CALLY index<3.5 (P = .02) were independent predictors of disease-free survival, while obstructive jaundice drainage (P < .01), poorly differentiated tumor (P < .01), and CALLY index <3.5 (P = .02) were independent predictors of overall survival. Conclusion: The CALLY index may be an independent and significant indicator of poor long-term outcomes in patients with distal cholangiocarcinoma after pancreaticoduodenectomy, suggesting the importance of comprehensive assessment for inflammatory status.

Clinical Features and Treatment Outcomes of Pseudoaneurysm Following Pancreatic Resection.

BACKGROUND/AIM: Management strategies for pseudoaneurysm rupture after pancreatic resection have not yet been firmly established due to its low incidence and effects of environmental variability among centers. This study aimed to provide a basis for treatment strategy improvement. PATIENTS AND METHODS: Clinical features and outcomes of 29 patients who experienced pseudoaneurysm formation or rupture following pancreatic resection were retrospectively reviewed. RESULTS: The incidence of pseudoaneurysm formation was 2.8%. In 28 of 29 patients, pseudoaneurysm was identified via emergent dynamic computed tomography (CT). The rates of complete cessation of bleeding by interventional radiology (IVR) and surgical intervention were 88% and 100%, respectively. Mortality rate was 13.8%. Four patients treated by IVR died, including three of massive bleeding and one of liver failure. CONCLUSION: Patients with suspected pseudoaneurysm rupture after pancreatic resection should undergo immediate CT. Open surgery is preferable for patients with incomplete hemostasis by IVR or those who cannot immediately undergo IVR, however, IVR is an effective alternative.

Usefulness of blood flow evaluation with indocyanine green fluorescence imaging during laparoscopic surgery for strangulated bowel obstruction: A cohort study.

INTRODUCTION: Intestinal blood flow evaluation during strangulated bowel obstruction is often based on the subjective assessment of the operator. Therefore, we aimed to comprehensively determine the presence or absence of intestinal blood flow based on normal light and indocyanine green (ICG) fluorescence imaging. Moreover, we ascertained whether the chosen surgical plan was appropriate, based on the patients' postoperative course and pathological findings. METHODS: All 14 patients diagnosed with strangulated bowel obstruction at our hospital who underwent laparoscopic surgery between July 2019 and January 2021 were enrolled. Surgical plans were chosen based on normal light imaging combined with near-infrared imaging after intravenous ICG injection. Intestinal resection was performed via a small laparotomy if resection was considered necessary. In the intestinal resection group, the presence of intestinal necrosis was examined based on the pathological findings of the resected specimens. In the intestinal preservation group, postoperative complications, such as delayed intestinal perforation and intestinal stricture, were examined. RESULTS: Intestinal resection was performed in 4 cases. The pathological findings of the resected specimens showed necrosis of the small intestine in all cases. No intra-abdominal complication occurred any of the cases, and the median postoperative hospital stay was 9.9 days. CONCLUSIONS: The selection of a surgical plan in conjunction with ICG fluorescence findings was valid in all 14 cases. ICG fluorescence imaging is useful in laparoscopic surgery for strangulated bowel obstruction and may be a novel method for evaluating intestinal blood flow during surgery.