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 .

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.

Intraoperative Holographic Guidance Using Virtual Reality and Mixed Reality Technology During Laparoscopic Colorectal Cancer Surgery.

BACKGROUND/AIM: This study aimed to investigate the feasibility of a mixed reality (MR)-based hologram for intraoperative navigation in colorectal surgery. Virtual reality (VR) and MR technologies can visualize overlapping three-dimensional (3D) hologram images and real space using the wearable HoloLens2 glasses. PATIENTS AND METHODS: This study comprised 13 patients with colorectal cancer. Twelve participants had hologram images created from computed tomography (CT) between August and September 2021. One patient who underwent lateral lymph node dissection (LLND) after this period was included. A 3D hologram of the arteries, veins, and tumor was downloaded to HoloLens2 with the Holoeyes MD system and used during surgery. Hologram visibility, surgical outcome, and the NASA Task Load Index (TLX) were examined. RESULTS: A total of 2 ileocecal resections, 6 right hemicolectomies, 1 partial colectomy, 4 LLNDs, and 1 para-aortic lymph node dissection were performed safely while viewing the holograms. The mean operative duration was 421 [290-555] min, blood loss was 5 [5-15] ml, and the postoperative hospital stay was 10 [9-14] days. Regarding the TLX, the mental demand score was 30 [20-40], the physical demand score was 60 [50-67.5], the temporal demand score was 50 [40-62.5], the performance score was 15 [2.5-35], the effort score was 45 [35-62.5], the frustration score was 60 [50-65], and the weighted workload score was 34 [30.17-45.835]. CONCLUSION: Viewing a hologram in VR/MR can improve the understanding of the anatomy, which cannot be ascertained on a conventional two-dimensional monitor. Holographic guidance is a highly novel surgical concept that can potentially reduce the mental demand on surgeons.

Fluorescent ureteral catheters in laparoscopic surgery for rectal cancer with invasion of the uterus: A case report.

Introduction: Resection of the uterus is required in some cases of colorectal cancer with invasion of the uterus. Localisation of the ureters to prevent ureteral injuries is important during resection of advanced colorectal cancer and combined resection of the uterus. Case presentation: We report a case of a woman in her 80s with rectal cancer with invasion of the uterus. She presented with appetite loss and lower abdominal pain. She was hospitalised after being diagnosed with intestinal obstruction due to rectal cancer. Colonoscopy revealed a tumor involving 100% of the circumference of the rectosigmoid colon, and imaging showed rectal cancer with invasion of the uterus and a giant uterine fibroid. Fluorescent ureteral catheters were placed bilaterally under cystoscopy, and laparoscopic anterior rectal resection, combined hysterectomy, and bilateral adnexectomy were performed 1 day later. Near-infrared visualisation of these catheters enabled safe release of the surrounding tissues from the uterus. Clinical discussion: Surgical treatment of rectal cancer with invasion of the uterus is not standardised and requires more complicated procedures, which are associated with a high risk of ureteral injury. Fluorescent ureteral catheters allow visualisation of the course of the ureters without releasing them, thereby enabling safe surgery. Conclusion: In fluorescence-guided surgery for rectal cancer, fluorescent ureteral catheters are particularly useful in patients with suspected invasion of other organs.

Intraoperative Tumor Identification During Laparoscopic Distal Gastrectomy: a Novel Fluorescent Clip Marking Versus Metal Clip Marking and Intraoperative Gastroscope.

BACKGROUND: In complete laparoscopic distal gastrectomy, the gastric resection line is difficult to determine due to a lack of tactile sensation. The use of intraoperative gastroscopy and intraoperative radiography has been reported, but the burden on personnel and technical complexity present impediments. In our department, based on lesion extent determined with preoperative gastroscopy, a fluorescent clip is used to mark the oral side of the lesion, which is resected after confirmation with a fluorescent laparoscopic system. In this study, we investigated the efficacy of fluorescent clip marking (FCM) in achieving an accurate resection line and reducing the operative time. METHODS: Fifty-six patients with gastric cancer who underwent complete laparoscopic distal gastrectomy from January 2018 to March 2021 were divided into two groups: the FCM group (n = 32) and the conventional metal clip marking and intraoperative gastroscopy (MCMG) group (n = 24). Short-term outcomes, including the resection margins, gastric resection time, and operative time, were compared and examined. RESULTS: The fluorescent clips were visible in all cases, and all stumps were negative according to permanent preparations. The operative times for FCM and MCMG were 350 (216-533) vs. 373.5 (258-651) min, respectively, with no significant difference (p = 0.316), while the gastric resection times were 636.5 (321-2572) vs. 1457.5 (843-4973) s, respectively, and were significantly shorter in the FCM group (p < 0.0001). CONCLUSIONS: FCM shortened the gastric resection time and could possibly shorten the operative time. FCM is feasible and safe and can potentially be used as a tumor-marking agent to determine accurate surgical resection lines. CLINICAL TRIAL REGISTRATION: Examination of Gastric Cancer, Research Ethics Committee of the Kawaguchi Municipal Medical Centre (Saitama, Japan), approval number: 2019-33. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

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.

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.

A case in which a near-infrared ray catheter (NIRC) was effectively applied in laparoscopic sigmoidectomy for a sigmoidovesical fistula.

A 40-year-old man visited the hospital for a refractory urinary tract infection. A sigmoidovesical fistula resulting from a sigmoidovesical diverticulum was diagnosed, and laparoscopic surgery was performed. To avoid ureteral injury during surgery for highly advanced cancer and inflammatory diseases, a ureteral stent is generally placed before the procedure. However, in this case, surgery was performed using a near-infrared ray catheter (NIRC), which emits fluorescence when irradiated with near-infrared light. By clearly observing the pathway of the ureter via near-infrared light, the integrity of the ureter could be preserved, and sigmoidectomy was safely performed. The visual navigation of the ureter with NIRC was especially useful during surgery for a colovesical fistula with marked surrounding inflammatory changes and a high risk of ureteral damage.

Fluorescence ureteral navigation during laparoscopic surgery for clinically suspected stage T4 colorectal cancer: A cohort study.

BACKGROUND: Approximately 15% of patients with colorectal cancer present with locally advanced tumors (T4 stage). Laparoscopic surgery for stage T4 disease has not yet been established. The near-infrared ray catheter fluorescent ureteral catheter (NIRFUC) is a new device that uses near-infrared fluorescence resin. We examined the utility of fluorescence ureteral navigation (FUN) with the NIRFUC during laparoscopic surgery for stage T4 colorectal cancer. MATERIALS AND METHODS: Patients with stage T4 colorectal cancer (n = 143, from January 2017 to March 2021) were divided into a T4FUN + group, in which the NIRFUC was used (n = 21), and a T4FUN- group, in which the NIRFUC was not used (n = 122). Short-term outcomes were compared between the groups. Next, the laparoscopic surgery rate and incidence of ureteral injury from January 2017 to March 2021 were compared between the T4FUN- group and the non-stage T4FUN- group (n = 434, from January 2017 to March 2021), in which fluorescence ureter navigation was not used. RESULTS: Rectal cancer, stage T4b disease, and invasion into the urinary tract were observed more often in the T4FUN + group than in the T4FUN- group. In the comparisons of the T4FUN + versus T4FUN- groups, the operative time was 398 (161-1090) vs. 256 (93-839) minutes, the blood loss was 10 (1-710) vs. 25 (0-1360) ml, and the ratio of laparoscopic surgery to open surgery was 21:0 vs. 79:43. Postoperative complications (Clavien-Dindo grade ≥ III) were present in 2 (10%; 0 ureteral injury) patients in the T4FUN + group and 13 (11%; 2 ureteral injury) patients in the T4FUN- group. In the T4FUN + group, the operative time was longer (p < 0.0001), but the laparoscopic ratio was higher (p = 0.0002), and the blood loss volume and incidence of ureteral injury tended to be lower. In the comparisons of the T4FUN- versus non-stage T4FUN- groups, the ratio of laparoscopic surgery to open surgery was 79:43 vs. 384:50, the incidence of open conversion was 8 (6.6%) vs. 15 (3.5%), and the incidence of ureteral injury was 2 (1.6%) vs. 0 (0%). In the T4FUN- group, the open surgery rate (<0.0001), open conversion rate (p = 0.0205) and incidence of ureteral injury (p = 0.0478) were high, with a significant difference observed between the groups. CONCLUSION: Patients with stage T4 disease have an increased risk of ureteral injury and are more likely to be converted to open surgery. FUN can help to safely increase the laparoscopic surgery rate while safely visualizing the ureter. FUN is recommended for laparoscopic surgery in patients with stage T4 colorectal cancer. 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/clinical research-r02.pdf.

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.

Intestinal blood flow evaluation using the indocyanine green fluorescence imaging method in a case of incarcerated obturator hernia: A case report.

In surgery for incarcerated hernia, intestinal blood flow is an important factor in intraoperative decision-making given that irreversible ischemia can result in intestinal necrosis. Here, we report a case of incarcerated obturator hernia in which the bowel was successfully preserved by evaluating intestinal blood flow with the indocyanine green fluorescence imaging method. A woman in her 80s was diagnosed with incarcerated right obturator hernia, and a laparoscopic operation was performed. The small bowel tissue that had been incarcerated exhibited dark red discoloration. Fluorescence examination of the bowel wall indicated that the ischemic changes were reversible, and accordingly, the bowel was not resected. The postoperative course was uneventful. The indocyanine green fluorescence imaging method is a useful new source of evidence that will improve intraoperative decision-making regarding bowel ischemia.

New Technique of Laparoscopic Paraaortic Lymph Node Dissection for Colorectal Cancer Using Fluorescence Navigation.

Background/Aim: According to limited current reports, therapeutic paraaortic lymph node (PALN) dissection with intensive combined therapy for colorectal cancer improves prognosis in select patients. Laparoscopic PALN dissection is a difficult technique that has not yet been established. We applied this procedure using an intraoperative fluorescence navigation technique with a near-infrared ray catheter (NIRC™) fluorescent ureteral catheter (NIRFUC). Patients and Methods: We evaluated the utility of laparoscopic fluorescence navigation and the short-term outcomes of 6 patients undergoing laparoscopic PALN dissection. Results: There were 3 surgeries for synchronous metastasis and 3 surgeries for recurrent metastasis. The mean surgical duration, blood loss, and postoperative hospital stay were 677 (range=518-1,090) min, 7.5 (range=3-1,600) ml, and 14 (range=9-33) days, respectively. Postoperative complications (Clavien-Dindo grade >III) occurred in 1 case. Conclusion: Dissection around the ureter was navigated with a NIRFUC. Fluorescence ureteral navigation facilitated completion of the complex laparoscopic PALN dissection procedure.