Complications associated with loop ileostomy: analysis of risk factors.

BACKGROUND: Loop ileostomy is a common surgical procedure but is associated with complications such as outlet obstruction (OO), parastomal hernia (PH), and high-output stoma (HOS). This study aimed to identify risk factors for these complications, as well as their causal relationships. METHODS: The study included 188 consecutive patients who underwent loop ileostomy between April 2016 and September 2021. Clinical factors and postoperative stoma-related complications (OO, HOS, and PH) were analyzed retrospectively. Stoma-related factors were evaluated using specific measurements from computed tomography (CT) scans. The incidence, clinical course, and risk factors for the stoma-related complications were investigated. RESULTS: OO was diagnosed in 28 cases (15.7%), PH in 60 (32%), and HOS in 57 (31.8%). A small longitudinal stoma diameter at the rectus abdominis level on CT and a right-sided stoma were significantly associated with OO. Creation of an ileostomy for anastomotic leakage was independently associated with HOS. Higher body weight and a large longitudinal stoma diameter at the rectus abdominis level on CT were significantly associated with PH. There was a significant relationship between the occurrence of OO and HOS. However, the association between OO and PH was marginal. CONCLUSION: This study identified key risk factors for OO, HOS, and PH as complications of loop ileostomy and their causal relationships. Our findings provide insights that may guide the prevention and management of complications related to loop ileostomy.

Enzymatic Fat Dissolution Improves Detection of Small Lymph Nodes in Colon Cancer Surgery.

Background Accurate lymph node evaluation is essential for staging colon cancer and guiding postoperative treatment decisions. In this study, we compared the efficacy of a simple enzymatic fat dissolution method with the conventional method for lymph node sampling from specimens after colon cancer surgery. Methods We enrolled 58 patients who underwent elective laparoscopic surgery for colon adenocarcinoma between May 2018 and May 2021 at Fukuoka University Hospital in Fukuoka, Japan. The specimens from these patients were treated using fat dissolution and were compared with specimens from 58 patients for which conventional manual palpation was used. Results A significantly greater number of lymph nodes were detected by the fat dissolution method compared with the conventional method (average per patient, 27.5 vs. 22.6, P = 0.02). In particular, the between-group difference was significant for lymph nodes measuring <5 mm (average per patient, 26.1 vs. 20.9; P = 0.01). Multivariate analysis showed that, compared with the conventional method, the fat dissolution method was significantly associated with the identification of lymph node metastasis. The positive rate of lymph nodes ≥10 mm in diameter was markedly higher along the inferior mesenteric artery than the ileocolic artery (100% vs. 52.6%). Conclusions The use of the fat dissolution method led to an increase in the number of small lymph nodes detected. Rates of metastasis according to lymph node size may depend on the lymph node station.

Effect of heating insufflation tube of AirSeal system on laparoscopic surgery.

The AirSeal system (CONMED, NY, USA) can outstandingly keep pneumoperitoneum stable. However, water droplets form on the access port, impairing the performance of comfortable surgical procedures because of the resultant wet surgical field. This study was performed to clarify the mechanism of water droplet formation and to prevent it. Condensation was observed on the AirSeal system. A heater was wrapped around the tri-lumen tube, and the heating effect was assessed. The simulator experiments revealed that condensation formed in the tri-lumen tube and on the wall of the access port. The accumulated weight of the condensation on the wall of the access port was 41.6 g in the Heated group, 138.2 g in the Control group, and 479.4 g in the Cooled group. In the clinical assessment, the accumulated volume of the condensation attached to the inside wall was significantly smaller in the Heated group than in the Unheated group (111.7 g vs. 332.9 g, respectively). We clarified that the volume of condensation attached to the wall of the access port depended on the temperature of the tri-lumen tube. The clinical study revealed that the condensation on the access port was reduced by heating the tri-lumen tube. The development of a novel heating device for the insufflation tube would be effective and useful.

Jejunal gastrointestinal stromal tumor that developed in a patient with neurofibromatosis type 1: a case report.

BACKGROUND: Neurofibromatosis type 1 (NF1) is known to be associated with the frequent occurrence of unique gastrointestinal stromal tumors (GISTs), preferably occurring in the small intestine, with no mutations in the c-kit proto-oncogene or platelet-derived growth factor receptor-alpha (PDGFRA), with a high tendency for multifocal development, indolent nature, with low proliferation activity and favorable prognosis. CASE PRESENTATION: A woman in her forties visited her local doctor complaining of menstrual pain; a large mass was detected in her lower abdomen, and she was referred to our hospital. The patient had hundreds of skin warts and café au lait spots. The patient's mother had been diagnosed with type 1 neurofibromatosis. The patient met the diagnostic criteria for NF1 and was diagnosed with NF1. Ultrasonography showed a large heterogeneous cystic mass with various echo patterns, solid compartments and multiple septations. Magnetic resonance imaging showed a multilocular cystic mass with liquid content exhibiting various intensities, including that of blood. A small round solid mass was also observed close to the cystic tumor. Contrast-enhanced computed tomography showed that the round solid mass showed strong enhancement in the early phase, unlike the cystic tumor component. Open laparotomy revealed a multicystic exophytic tumor measuring 11.5 cm originating from the jejunal wall, 20 cm distal to the duodenojejunal flexure. A solid tumor measuring 2.1 cm was also found on the anal side of the large tumor. We resected the short segment of the jejunum, including the two lesions. Microscopic findings revealed that the cystic and solid tumors consisted of spindle-shaped tumor cells showing little atypia with a fascicular or bundle arrangement. Nuclear mitosis was scarce. Immunostaining of the tumor cells showed positive staining for KIT and DOG1 and negative staining for S100 and desmin. The NF1 patient was diagnosed with multiple GISTs accompanied by intratumoral hemorrhagic denaturation arising from the jejunum. The TNM staging was pT4N0M0, stage IIIA. CONCLUSION: We report a case of GISTs associated with NF1 that showed a jejunal origin, multifocal development and few mitotic figures. The recurrence risk, survival prognosis and need for adjuvant chemotherapy, particularly in cases where the initial GIST exhibits a very indolent pathology in NF1-related GISTs, remain to be elucidated.

Histological transformation to signet-ring cell carcinoma in a patient with clinically aggressive poorly differentiated adenocarcinoma of the ascending colon after response to chemotherapy plus cetuximab: a case report.

BACKGROUND: Alteration of chemosensitivity or tumor aggressiveness in response to chemotherapy has been reported, and liquid biopsy assessment during chemotherapy for colorectal cancers has confirmed the acquisition of mutations in various oncogenes. However, the occurrence of histological transformation seems to be extremely rare in colorectal cancers, and the few existing case reports of this transformation are from lung cancer and breast cancer. In this report, we describe the histological transformation of clinically aggressive scirrhous-type poorly differentiated adenocarcinoma of the ascending colon to signet-ring cell carcinoma in almost all recurrent tumors that were confirmed by autopsy after response to chemotherapy plus cetuximab. CASE PRESENTATION: A 59-year-old woman visited our hospital with whole abdominal pain and body weight loss and was diagnosed with scirrhous-type poorly differentiated adenocarcinoma of the ascending colon with aggressive lymph node metastases. The intrinsic chemosensitivity of the tumors was evident upon initiation of mFOLFOX6 plus cetuximab therapy, and right hemicolectomy was performed, and the tumor obviously remained in the peripancreatic area, paraaortic region, or other retroperitoneal areas. The ascending colon tumors mainly consisted of poorly differentiated adenocarcinoma and were not associated with signet-ring cell components except for minute clusters in a few lymphatic emboli in the main tumor. Chemotherapy was continued, and metastases were eliminated at 8 months after the operation; this response was maintained for an additional 4 months. Discontinuation of chemotherapy plus cetuximab resulted in immediate tumor recurrence and rapid expansion, and the patient died of the recurrent tumor 1 year and 2 months after the operation. Autopsy specimens revealed that almost all of the recurrent tumors exhibited transformation and consisted of signet-ring cell histology. CONCLUSION: This case might suggest that various oncogene mutations or epigenetic changes resulting from chemotherapy, especially regimens that include cetuximab, contribute to the transformation of non-signet-ring cell colorectal carcinoma to signet-ring cell carcinoma histology and can promote the aggressive clinical progression characteristic of signet-ring cell carcinoma.

Detection of carbon dioxide embolism by transesophageal echocardiography during transanal/perineal endoscopic surgery: a pilot study.

The transanal/perineal (ta/tp) endoscopic approach has been widely used for anorectal surgery in recent years, but carbon dioxide embolism is a possible lethal complication. The frequency of this complication in this approach is not known. In this study, we investigated the frequency of intraoperative (including occult) carbon dioxide embolism using transesophageal echocardiography. Patients who underwent surgery via the ta/tp approach and consented to participate were included. Intraoperative transesophageal echocardiography was used to observe the right ventricular system in a four-chamber view. Changes in end-tidal carbon dioxide (EtCO2), oxygen saturation (SpO2), and blood pressure were taken from anesthesia records. Median maximum insufflation pressure during the ta/tp approach was 13.5 (12-18) mmHg. One patient (4.8%) was observed to have a bubble in the right atrium on intraoperative transesophageal echocardiography, with a decrease in EtCO2 from 39 to 35 mmHg but no obvious change in SpO2 or blood pressure. By lowering the insufflation pressure from 15 to 10 mmHg and controlling bleeding from the veins around the prostate, the gas rapidly disappeared and the operation could be continued. Among all patients, the range of variation in intraoperative EtCO2 was 5-22 mmHg, and an intraoperative decrease in EtCO2 of > 3 mmHg within 5 min was observed in 19 patients (median 5 mmHg in 1-10 times).Clinicians should be aware of carbon dioxide embolism as a rare but potentially lethal complication of anorectal surgery, especially when using the ta/tp approach.

Comparison of oncological outcomes between low anterior resection and abdominoperineal resection for rectal cancer: A retrospective cohort study using a multicenter database in Japan.

BACKGROUND: It remains controversial whether the abdominoperineal resection (APR) procedure itself has a negative impact on prognosis compared with sphincter-saving surgery (SSS). The purpose of this study was to investigate whether the operation type affects the prognostic outcome in rectal cancer using a multicenter database in Japan. METHODS: The study involved 2533 patients who underwent APR or SSS and were registered in the Japanese Society for Cancer of the Colon and Rectum database, which includes data from 74 centers, between 2003 and 2007. The primary endpoints were overall survival (OS) and relapse-free survival (RFS). The secondary endpoints were local recurrence rate (LRR) and pathological radial margin (pRM) status. RESULTS: Multivariate analysis identified pathological tumor depth, lymph node status, and pRM status to be associated with oncological outcomes (OS, RFS, LRR). Although the oncological outcomes were worse after APR than after SSS in univariate analysis, there was no significant difference in OS (hazard ratio 1.08; 95% confidence interval [CI] 0.85-1.37) or RFS (hazard ratio 1.06; 95% CI 0.87-1.30) between APR and SSS. There was also no significant difference in LRR (odds ratio 1.11, 95% CI 0.70-1.77). Multivariate analysis showed that operation type was associated with positive pRM (odds ratio 3.13, 95% CI 0.18-0.56). CONCLUSIONS: There was no significant difference in oncological outcomes between APR and SSS for rectal cancer. The risk of positive pRM was higher for APR and performing radial margin-negative surgery is an important factor in improving the oncological outcomes of APR.

Relationship between perioperative oncological evaluation and recurrence using circulating tumor DNA with KRAS mutation in patients with colorectal cancer.

BACKGROUND: The detection of circulating tumor DNA (ctDNA) in colorectal cancer (CRC) by liquid biopsy may have prognostic information. In this perioperative study, we evaluate if there is a relationship between mutant allele frequency (MAF) of Kirsten rat sarcoma viral oncogene homolog (KRAS) and tumor recurrence and how that could be useful in the early detection of recurrence. METHODS: Among 304 cases of colorectal cancer surgery, ctDNA was sampled from the perioperative blood of 84 patients with CRC with KRAS mutation (exon 4 p.A146T, exon 4 p.A146V, exon 2 p.G12A, exon 2 p.G12C, exon 2 p.G12D, exon 2 p.G12S, exon 2 p.G12V, exon 2 p.G13D, exon 3 p.Q61H) and analyzed using the digital polymerase chain reaction system. The median observation period was 26 months. RESULTS: Although the relationship between the perioperative MAF of KRAS and recurrence was not proved, tumor diameter, tumor depth, and stage were correlated with the preoperative MAF of KRAS (p = 0.034, p = 0.002, p = 0.008). However, tumor diameter, tumor depth, and stage did not correlate with MAF of KRAS at postoperative day 30. CONCLUSIONS: In this study, pathological tumor size, tumor depth, and stage were correlated with preoperative MAF of KRAS, but it was unreliable to predict recurrence by detection of ctDNA with KRAS mutation in the perioperative period of colorectal surgery.

Intraoperative pressure monitoring of the lower leg for preventing compression-related complications associated with the lithotomy position.

BACKGROUND: Several serious complications are associated with the lithotomy position, including well-leg compartment syndrome and peroneal nerve paralysis. The aims of this study were to identify risk factors for the intraoperative elevation of lower leg pressure and to evaluate the effectiveness of monitoring external pressure during surgery for preventing these complications. METHODS: The study included 106 patients with a diagnosis of sigmoid colon or rectal cancer who underwent elective laparoscopic surgery between June 2019 and December 2020. We divided the posterior side of the lower leg into four parts (upper outside, upper inside, lower outside, lower inside) and recorded the peak pressure applied to each area at hourly intervals during surgery (called "regular points") and when the operating position was changed (e.g., by head-tilt or leg elevation; called "points after change in position"). When the pressure was observed to be higher than 50 mmHg, we adjusted the position of the leg and re-recorded the data. Data on postoperative leg-associated complications were also collected. RESULTS: The pressure was measured at a total of 1125 points (regular, n = 620; after change of position, n = 505). The external pressure on the upper outer side of the right leg (median, 36 mmHg) was higher than that on any other area of the lower leg. The pressure increase to more than 50 mmHg was observed not only during the change of position (27.5%) but also during regular points (22.4%). Bodyweight, strong leg elevation, and low head position were identified as factors associated with increased external pressure. There have been no compression-related complications in 534 cases at our institution since the introduction of intraoperative pressure monitoring. CONCLUSIONS: Several risk factors associated with increased external pressure on the lower leg were identified. Intraoperative pressure monitoring might help reduction of pressure-related complications, needing further and larger prospective data collections.

Combined laparoscopic and transperineal endoscopic total pelvic exenteration for the vaginal stump recurrence of cervical cancer.

Total pelvic exenteration (TPE) is sometimes required for radical treatment of locally advanced or recurrent gynecologic cancer [1]. However, TPE with a transabdominal approach requires highly advanced techniques in the case of repeated surgery due to the effects of primary surgery and/or chemoradiotherapy, especially when a transabdominal approach is used. Recent technical advances in transanal/transperineal endoscopic surgery have proved beneficial for complicated surgery in the deep pelvis [2]. Here we introduce our surgical procedure for combined laparoscopic and transperineal endoscopic TPE (TpTPE) for pelvic recurrence of cervical cancer. A 42-year-old woman was diagnosed with vaginal stump recurrence of cervical cancer involving the rectum, bladder, and ureters following hysterectomy and pelvic lymph node dissection as primary surgery and chemotherapy/chemoradiotherapy for previous recurrences. We decided to perform TpTPE with a combined laparoscopic approach. The GelPOINT advanced access platform was fixed through a perineal skin incision around the tightly closed anus, external urethral orifice, and vagina. With sufficient pneumopelvic pressure (12 mmHg), TpTPE was performed under a good surgical view without any effect of the primary surgery. A ureterostomy and sigmoid colostomy were created and a right gracilis muscle flap was used to reconstruct the pelvic defect. The total operative time and estimated blood loss were 887 minutes and 497 mL, respectively. Histopathological examination revealed recurrent cervical cancer invading the rectum, bladder, and bilateral ureters with negative surgical margins. The postoperative course was uneventful except for paralytic ileus. The patient was discharged on postoperative day 18. TpTPE is a technically feasible and effective approach for locally advanced pelvic tumors.

Oncological evaluation in the perioperative period using cfDNA with BRAF V600E mutation in patients with colorectal cancer.

The detection of circulating cell-free DNA (cfDNA) by liquid biopsy is reported to provide prognostic information in colorectal cancer (CRC). Although the frequency of BRAF V600E mutation in CRC is less than 10%, it is associated with poor responses to conventional chemotherapy. We conducted a prospective study to investigate the relationship between the perioperative mutant allele frequency (MAF) of BRAF V600E and tumor recurrence, and to evaluate the possibility of early detection of recurrence. Among 362 patients who underwent radical resection, cfDNA was extracted from the perioperative blood of 11 CRC patients with BRAF V600E mutation and analyzed using the digital polymerase chain reaction (dPCR) system. The median follow-up time was 22 months, and there were four cases of recurrence. Although there was no correlation between recurrence and the perioperative MAF of BRAF V600E, tumor diameter was correlated with the MAF (p = 0.024), and the MAF increased with time in two patients from whom additional samples were obtained prior to recurrence. In this study, we identified a correlation between the pathological tumor diameter and the MAF, but it was difficult to predict recurrence by measuring cfDNA with BRAF V600E mutation in the perioperative period of radical resection of CRC.

Preoperative T staging of advanced colorectal cancer by computed tomography colonography.

PURPOSE: Accurate preoperative T staging is important when determining the treatment strategy for advanced colorectal cancer. We have previously reported the usefulness of preoperative T staging based on the spatial relationship of tumors and "bordering vessels" by computed tomography colonography (CTC) with multiplanar reconstruction (MPR). The aims of this study were to evaluate the external validity of this method and to determine whether there is a difference in the accuracy of T staging between the mesenteric and antimesenteric sides. METHODS: The study subjects were 110 patients with colorectal cancer who underwent preoperative CTC and surgical resection from June 2016 to March 2018. Preoperative T stage was determined by CTC based on the relationship between the tumor and the bordering vessels and compared with the pathological T stage. The influence of tumor location, namely, whether the tumor was on the antimesenteric or mesenteric side, on preoperative T staging was assessed in 78 patients with colorectal cancer. RESULTS: Sensitivity, specificity, accuracy, positive, and negative predictive values were respectively, 65%, 91%, 83%, 76%, and 85% for T2 (n = 34); 76%, 82%, 81%, 50%, and 94% for T3 (n = 23); and 77%, 93%, 87%, 86%, and 88% for T4a disease (n = 39). Overall right answer rate was 83.3% (15/18) for the mesenteric side and 65% (39/60) for the antimesenteric side (n = 0.14). CONCLUSION: Diagnostic criteria based on the bordering vessels seen on CTC images with MPR are useful for T staging of colorectal cancer. However, the accuracy differs between the antimesenteric and mesenteric sides.

[A Case of Internal Jugular Vein Thrombosis Caused by Gravity-Induced Catheter Excursion following Subcutaneous Implantable Central Venous Port Insertion for Colorectal Cancer Treatment].

The patient was a 66-year-old woman. She underwent central venous port insertion as part of postoperative adjuvant chemotherapy for sigmoid colon cancer. At the beginning of the 2 cycle, she experienced discomfort in the neck, and computed tomography was performed. As a result, catheter deviation and a thrombus in the internal jugular vein were observed. It was considered that breast displacement due to gravity caused the catheter deviation and that the position of the tip of the catheter deviating to immediately above the venous valve caused thrombus formation. We examined the factors that may cause catheter deviation.

Two case of bilateral approach in laparoscopic pancreas-sparing distal duodenectomy for duodenal neoplasms arising from the distal duodenum.

INTRODUCTION: Laparoscopic pancreas-sparing distal duodenectomy is a less invasive surgical therapy; however, the anatomical complexity of the duodenum increases the difficulty of laparoscopic procedures. We introduce our technique for laparoscopic pancreas-sparing distal duodenectomy for distal duodenal tumors. PRESENTATION OF CASES: A first patient was 47-year-old woman who had 30 mm of duodenal tumor which located in third portion of duodenum. A second patient was 66-year-old man who had 35 mm of submucosal tumor which located in the third portion of duodenum. Laparoscopic pancreas-sparing duodenectomy was performed using bilateral approach for both cases. We began by dissecting an avascular area on the right side of the transverse mesocolon to mobilize the second and third portions of the duodenum with the uncinate process of the pancreas. Next, from the left side, the jejunum and the fourth portion of the duodenum were fully mobilized orally from the surrounding tissue, connecting the dissection plane with the right-side area. The jejunum and duodenum were cut with a linear stapler. Intracorporeal reconstruction was performed in an overlapped manner. We performed this procedure in two patients. Operative time was 326 and 370 min, respectively. Patients were discharged on postoperative days 9-12 without postoperative complications. DISCUSSION: Duodenal tumors are found increasingly often because of developments in endoscopic technology and techniques; therefore, establishing safe surgical procedures for duodenal tumor excision is imperative. Our surgical approach was simple and safe procedure. CONCLUSION: Laparoscopic pancreas-sparing distal duodenectomy with a bilateral approach is a useful approach without wide mobilization of duodenum.

Heterotopic ossification in lymph node metastasis after rectal cancer resection: a case report and literature review.

BACKGROUND: Heterotopic ossification (HO) is the formation of osseous tissue outside the skeleton. HO in malignant tumors of the digestive tract is extremely rare, as is ossification in metastatic lesions from HO-negative digestive tract tumors. Regarding the pathogenesis of HO, two theories have been proposed. The first is that the osteoblastic metaplasia of tumor cells (driven by the epithelial-mesenchymal transition, EMT) results in HO, and the second is that factors secreted by cancer cells lead to the metaplasia of stromal pluripotent cells into osteoblasts. However, the osteogenic mechanisms remain unclear. CASE PRESENTATION: An 83-year-old Japanese woman underwent low anterior rectal resection for rectal cancer before presentation at our institution, in June 2018. The final diagnosis was stage IIB rectal adenocarcinoma (T4aN0M0). Histological examination did not reveal HO in the primary tumor. Thirteen months after the operation, a solitary metastatic lesion in the brain 20 mm in size and a solitary metastatic lesion in a right axillary lymph node 20 mm in size were diagnosed. The patient was treated with gamma-knife therapy for the brain metastasis. One month later, she was referred to our institution. She underwent lymph node resection. Histological examination revealed that most portions of the affected lymph node were occupied by metastatic tumor cells and that central necrosis and four small ossified lesions without an osteoblast-like cell rim were present in the peripheral region. Immunohistochemical analysis showed tumor cells positive for BMP-2, osteonectin, osteocalcin, AE1/AE3, TGF-ß1, Gli2, Smad2/3, and CDX2 and negative for nestin, CD56, and CK7. CONCLUSION: This is the first English case report of HO in a metachronous metastatic lymph node after the curative resection of HO-negative rectal cancer. Unlike HO lesions in past reports, the HO lesion did not show peripheral osteoblast-like cells, and the immunohistochemical findings indicated that the present case resulted from the EMT.

Safety and effectiveness of high ligation of the inferior mesenteric artery for cancer of the descending colon under indocyanine green fluorescence imaging: a pilot study.

BACKGROUND: Complete mesocolic excision with central vascular ligation is a standard advanced technique for achieving favorable long-term oncological outcomes in colon cancer surgery. Clinical evidence abounds demonstrating the safety of high ligation of the inferior mesenteric artery (IMA) for sigmoid colon cancer but is scarce for descending colon cancer. A major concern is the blood supply to the remnant distal sigmoid colon, especially for cases with a long sigmoid colon. We sought to clarify the safety and feasibility of high ligation of the IMA in surgery for descending colon cancer using indocyanine green (ICG) fluorescence imaging. METHODS: In this prospective single-center pilot study, we examined 20 patients with descending colon cancer who underwent laparoscopic colectomy between April 2018 and September 2019. Following full mobilization and division of the proximal colonic mesentery, we temporarily clamped the root of the IMA and performed ICG fluorescence imaging of the blood flow to the sigmoid colon. The postoperative anastomosis-related complications (primary endpoint) and length of viable remnant colon, and the number of lymph nodes retrieved (secondary endpoints) were evaluated and compared with historical controls who underwent conventional IMA-preserving surgery (n = 20). RESULTS: Blood flow reached 40 (17-66) cm retrograde from the peritoneal reflection, even after IMA clamping. Accordingly, IMA high ligation was performed in all cases. No anastomotic anastomosis-related complications occurred in each group. Retrieved total lymph nodes were higher in number in the ICG-guided group than in the conventional group (p = 0.035). Specifically, more principal nodes were retrieved in the ICG-guided group, compared with the conventional group (p = 0.023). However, the distal margin was not as long compared with the conventional group. CONCLUSION: We demonstrated the safety and feasibility of high ligation of the IMA for descending colon cancer without sacrificing additional distal colon using fluorescence evaluation of blood flow in the remnant colon.

A case of carbon dioxide embolism during the transperineal approach in total pelvic exenteration for advanced anorectal cancer.

The transanal and transperineal endoscopic approaches are useful advanced surgical options for removing rectal and anorectal cancers. Intraoperative carbon dioxide (CO2 ) embolisms, however, have been increasingly reported as potentially fatal complications associated with surgery employing these approaches. We report our experience with a CO2 embolism that was detected because of a sudden drop in end-tidal CO2 with decreasing saturation of percutaneous arterial oxygen during total pelvic exenteration using the transperineal endoscopic approach under pneumopelvis/pneumoperitoneum. Transesophageal echocardiography confirmed that it was a CO2 embolus. We reversed the pneumopelvis and pneumoperitoneum, which alleviated the cardiopulmonary problems, and the surgery then proceeded to achieve R0 resection. The patient was discharged without severe complications other than the CO2 embolism.

Changes in Immunological Status in Patients With Metastatic Colorectal Cancer Treated With First-line Chemoimmunotherapy.

BACKGROUND/AIM: Chemoimmunotherapy is a promising treatment for various malignant diseases. In this study, we examined whether first-line chemoimmunotherapy using adoptive immune-cell therapy was effective for metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: The therapeutic efficacy and safety of the standard first-line chemoimmunotherapy with adoptive αß T cell therapy and bevacizumab were assessed using thirty-two patients with mCRC in our hospital. Immunological status after this chemoimmunotherapy was also evaluated. RESULTS: The response and disease control rates were 68.8% and 87.5%, respectively. Further, median progression-free and overall survival were 14.2 and 35.3 months. Immunotherapy-associated toxicity was minimal. Significant decrease in the change of monocyte number (p=0.006) and increase in the change of rate of lymphocyte-to-monocyte ratio (p=0.039) were seen in the complete response group. CONCLUSION: First-line chemoimmunotherapy with adoptive αß T cell therapy may be useful for mCRC.

Avoiding urethral and rectal injury during transperineal abdominoperineal resection in male patients with anorectal cancer.

BACKGROUND: In abdominoperineal resection (APR) in male patients with rectal cancer, high margin involvement and urethral injury have been reported to result from difficulty in dissecting the anterior anorectum. Recently, the efficacy of an endoscopic down-to-up rectal dissection was reported. Here, we present a safe and simple technique for anterior dissection using a simultaneous laparoscopic and transperineal endoscopic approach. METHODS: We perform transperineal APR (TpAPR) using both the laparoscopic and transperineal approach (a 2-team approach). Anterior dissection commences just behind the superficial transverse perineal muscle. Next, the striated muscle complex surrounding the rectum (levator ani and puborectalis muscle) is divided. At this point, it is difficult to identify the dissection plane between the membranous urethra and anterior rectum; thus, dissection along the lateral aspect of neurovascular bundle from the lateral to anterior side with the assistance of the laparoscopic team is helpful in identifying the posterior surface of the prostate. Once the prostate is identified, it is relatively easy to divide the rectourethralis muscles. The key steps of our procedure are shown in the video. RESULTS: Between April 2016 and July 2019, we performed 14 TpAPR procedures in male patients with rectal cancer without distant metastasis. Extended surgery was performed in 8 patients, including pelvic sidewall dissection and combined resection of adjacent organs. Median operative time was 453 min and median blood loss was 46 g. There was 1 (7.1%) circumferential-positive case, but no cases of urethral injury or rectal perforation. CONCLUSIONS: The 2-team TpAPR procedure is beneficial for appropriate dissection of the anterior side during APR surgery.