Development of a laparoscopic sigmoidectomy simulator: Sigmaster

The sigmoid colon simulator was designed to accurately reproduce the anatomical layer structure and the arrangement of characteristic organs in each layer, and to have conductivity so that energy devices can be used. Dry polyester fibers were used to reproduce the layered structures, which included characteristic blood vessels, nerve sheaths, and intestinal tracts. The adhesive strength of the layers was controlled to allow realistic peeling techniques. The features of the Sigmaster are illustrated through a comparison of simulated sigmoidectomy using Sigmaster and actual surgery. We developed a laparoscopic sigmoidectomy simulator called Sigmaster. Sigmaster is a training device that closely reproduces the membrane structures of the human body and allows surgeons to experience the entire laparoscopic sigmoidectomy process.

Transanal Total Mesorectal Excision for Rectal Cancer: Toward Standardization of the Surgical Technique

Laparoscopic surgery is widely used for rectal cancer; however, this technique is challenging due to tapering of the mesorectum in the pelvis, and the forward angle of the distal rectum, which renders this part of the rectum less accessible from the abdominal cavity. Hence, concerns regarding its safety and curability have been raised, particularly for inadequate distal and circumferential resection margins. Recently, transanal total mesorectal excision (TaTME), which involves endoscopic total mesorectal excision (TME) retrogradely from the anal side, has attracted attention worldwide as a solution to these problems. TaTME is superior to the conventional laparoscopic approach for rectal cancer in terms of both oncological and functional preservations. However, a shallow learning curve caused by the unfamiliar anatomical view from the anal side can pose challenges. Therefore, an efficient educational system needs to be established. Randomized controlled trials comparing conventional laparoscopic TME with TaTME are ongoing to demonstrate the usefulness of TaTME. This article reviews changes in the surgical treatment of rectal cancer, with a focus on TaTME, and describes the indications, surgical techniques, and training curricula for TaTME.

Can the Single-stapling Technique Following Intersphincteric Resection with Transanal Total Mesorectal Excision Become the New Standard Anastomosis?

For transanal total mesorectal excision (TaTME), the indication for single-stapling technique (SST) has been expanded to include lower anastomosis, even in intersphincteric resection (ISR). We focused on the anastomotic techniques following ISR with TaTME and examined the feasibility and safety of the SST below the anorectal junction (ARJ). Data on postoperative anastomosis-related complications and anorectal function was evaluated in comparison to conventional manual hand-sewn coloanal anastomosis in ISR with TaTME. We examined patients with 3-6 cm tumors from the anal verge who underwent ISR with TaTME between January 2018 and March 2020, and whose anastomotic line was located below the ARJ. Postoperative short-term outcomes and anorectal functions were compared. We also analyzed the effects of various factors on major low anterior resection syndrome (LARS) using multivariate logistic regression analysis. In total, 87 patients-48 in the hand-sewn anastomosis group and 39 in the SST group-were included in this study. SST below the ARJ in ISR with TaTME did not exacerbate surgical outcomes, including anastomosis-related complications. The SST group had a significantly lower LARS score as compared to the hand-sewn anastomosis group, and the proportion of major LARS was significantly lower. Only hand-sewn anastomosis was identified as a statistically significant independent risk factor for major LARS. In TaTME, SST below the ARJ was safe and feasible and had a lower negative impact on postoperative anastomosis-related complications and anorectal function as compared to hand-sewn anastomosis. Thus, SST is a promising anastomotic option for patients with low-lying rectal tumors.

Short-term outcomes following intracorporeal vs. extracorporeal anastomosis after laparoscopic right and left-sided colectomy: a propensity score-matched study

BACKGROUND

To compare the short-term outcomes of patients undergoing intracorporeal anastomosis (IA) during laparoscopic colectomy to those undergoing extracorporeal anastomosis (EA).

METHODS AND MATERIALS

The study was a single-centre retrospective propensity score-matched analysis conducted. Consecutive patients who underwent elective laparoscopic colectomy without the double stapling technique between January 2018 and June 2021 were investigated. The main outcome was overall postoperative complications within 30 days after the procedure. The authors also performed a sub-analysis of the postoperative results of ileocolic anastomosis and colocolic anastomosis, respectively.

RESULTS

A total of 283 patients were initially extracted; after propensity score matching, there were 113 patients in each of the IA and EA groups. There were no differences in patient characteristics between the two groups. The IA group had a significantly longer operative time than the EA group (208 vs. 183 min, P =0.001). The rate of overall postoperative complications was significantly lower in the IA group ( n =18, 15.9%) than in the EA group ( n =34, 30.1%; P =0.02), especially in colocolic anastomosis after left-sided colectomy (IA: 23.8% vs. EA: 59.1%; P =0.03). Postoperative inflammatory marker levels were significantly higher in the IA group on postoperative day 1 but not on postoperative day 7. There was no difference in the postoperative lengths of hospital stay between the two groups, and no deaths occurred.

CONCLUSION

The data suggest that performing IA during laparoscopic colectomy can potentially reduce the risk of postoperative complications, especially in colocolic anastomosis after left-sided colectomy.

Two-team lateral lymph node dissection assisted by the transanal approach for locally advanced lower rectal cancer: comparison with the conventional transabdominal approach

BACKGROUND

An optimal surgical approach to lateral lymph node dissection (LLND) remains controversial. With the recent popularity of transanal total mesorectal excision, a two-team procedure combining the transabdominal and transanal approaches was established as a novel approach to LLND. This study aimed to clarify the safety and feasibility of two-team LLND (2team-LLND) and compare its short-term outcomes with those of conventional transabdominal LLND (Conv-LLND).

METHODS

Between April 2013 and March 2020, 463 patients diagnosed with primary locally advanced rectal cancer underwent a transanal total mesorectal excision; among them, 93 patients who underwent bilateral prophylactic LLND were included in this single-center, retrospective study. Among these patients, 50 and 43 patients underwent Conv-LLND (the Conv-LLND group) and 2team-LLND (the 2team-LLND group), respectively. The short-term outcomes, including the operation time, blood loss volume, number of complications, and number of harvested lymph nodes, were compared between the two groups.

RESULTS

The intraoperative and postoperative complications in the 2team-LLND group were equivalent to those in the Conv-LLND group; furthermore, the incidence of postoperative urinary retention in the 2team-LLND group was acceptably low (9%). Compared with the Conv-LLND group, the 2team-LLND group had a significantly shorter operation time (P = 0.003), lower median blood loss (P = 0.02), and higher number of harvested lateral lymph nodes (P = 0.0005).

CONCLUSION

The intraoperative and postoperative complications of 2team-LLND were comparable with those of Conv-LLND. Thus, 2team-LLND was safe and feasible for advanced lower rectal cancer. Moreover, it was superior to Conv-LLND in terms of the operation time, blood loss volume, and number of harvested lateral lymph nodes. Therefore, it can be a promising LLND approach.

Single-center comparative study of short-term outcomes of transanal and laparoscopic total mesorectal excisions for low and middle rectal cancers

BACKGROUND

Transanal total mesorectal excision is a promising surgical treatment for rectal cancer. However, evidence regarding the differences in outcomes between the transanal and laparoscopic total mesorectal excisions is scarce. We compared the short-term outcomes of transanal and laparoscopic total mesorectal excisions for low and middle rectal cancers.

METHODS

This retrospective study included patients who underwent low anterior or intersphincteric resection for middle (5-10 cm) or low (< 5 cm) rectal cancer at the National Cancer Center Hospital East, Japan, from May 2013 to March 2020. Primary rectal adenocarcinoma was confirmed histologically. Circumferential resection margins (CRMs) of resected specimens were measured; margins ≤ 1 mm were considered positive. The operative time, blood loss, hospitalization length, postoperative readmission rate, and short-term treatment results were compared.

RESULTS

Four hundred twenty-nine patients were divided into two mesorectal excision groups: transanal (n = 295) and laparoscopic (n = 134). Operative times were significantly shorter in the transanal group than in the laparoscopic group (p < 0.001). The pathological T stage and N status were not significantly different. The transanal group had significantly lower positive CRM rates (p = 0.04), and significantly lower incidence of the Clavien-Dindo grade III (p = 0.02) and IV (p = 0.03) complications. Both groups had distal margin positivity rates of 0%.

CONCLUSIONS

Compared to laparoscopic, transanal total mesorectal excision for low and middle rectal cancers has lower incident postoperative complication and CRM-positivity rates, demonstrating the safety and usefulness of local curability for middle and low rectal cancers.

Single-stapling technique versus hand-sewn anastomosis in inter-sphincteric resection with transanal total mesorectal excision (Super SST): protocol for a multicentre randomized clinical trial

BACKGROUND

Currently, hand-sewn anastomosis is the standard procedure for inter-sphincteric resection (ISR); however, distal purse-string suturing during transanal total mesorectal excision (TaTME) has allowed a single-stapling technique (SST). Although it was originally intended for cases requiring anastomosis of 2 cm or more above the anorectal junction (ARJ), SST could be safely performed in ISR. The aim of this trial is to determine the superiority of SST over hand-sewn anastomosis in ISR with TaTME.

METHODS

The Super SST trial is a multicentre randomized clinical trial comparing stapled and hand-sewn anastomoses in ISR with TaTME. The trial will recruit patients scheduled for TaTME with anastomosis below the ARJ, who will be allocated 1:1 to receive either hand-sewn or stapled anastomosis. The primary endpoint is anastomosis-related complications within 30 postoperative days. Secondary endpoints include all early and late complications, operating time, reoperation, mortality rate, length of postoperative hospital stay, readmission, incidence of anal pain and rectal mucosal prolapse, length of temporary stoma retention, the proportion of patients with a temporary stoma at 1 year after surgery, and anorectal function at 1 year after surgery.

CONCLUSION

This trial will provide important clinical insights for new and promising anastomotic options for patients with very low rectal cancer. Registration number: UMIN000047818 (https://www.umin.ac.jp/ctr/index-j.htme).

Efficacy of transperineal minimally invasive surgery with laparoscopic abdominoperineal excision for lower rectal cancer

PURPOSE

In abdominoperineal excision (APE), the advantages of the "down-to-up" approach are expected to be more obvious when performed as a two-team approach, including transperineal minimally invasive surgery (TpMIS). We investigated the efficacy of TpMIS with laparoscopic APE for lower rectal cancer.

METHODS

Patients who underwent laparoscopic APE with (n = 20) or without (n = 30) TpMIS between December 2013 and April 2020 were retrospectively reviewed. Patient and tumor characteristics, intraoperative outcome, short-term outcome, and pathological findings were compared. Additional subgroup analyses were performed in technically challenging cases, including male patients, obese patients, and patients with tumors located at the anterior wall.

RESULTS

There was no marked difference in the patient or tumor characteristics or short-term outcomes, including morbidity and mortality between the two groups. Pathological results were comparable, and the circumferential resection margin (CRM) positive rate was 10% in both groups. TpMIS achieved a significant reduction in operative time (p = 0.02). In a subgroup analysis, the amount of blood loss was also smaller in males (p = 0.02) and patients with a high BMI (> 25) (p = 0.005) than in others.

CONCLUSION

Simultaneously performing TpMIS and laparoscopic APE is feasible owing to the favorable complication and CRM-positive rates. In terms of operative time and blood loss, TpMIS is expected to be advantageous in both easy and challenging cases.

Transanal total mesorectal excision for treating a lower rectal inflammatory myofibroblastic tumor: A case report

Rectal inflammatory myofibroblastic tumors are extremely rare, with no reports of their preoperative diagnosis. A 17-year-old woman who presented with low-grade fever, repeated diarrhea, constipation, and a 1-month history of anal pain was referred to our hospital. Rectal examination revealed a palpable hard mass with a smooth surface at the posterior wall 4 cm from the anal verge. Colonoscopy revealed a 4.0-cm submucosal tumor in the upper edge of the anal canal. Computed tomography and magnetic resonance imaging revealed a 5.0 × 4.0 cm-sized well-defined tumor contacting the rectum. Computed tomography-guided biopsy was performed, and an inflammatory myofibroblastic tumor was diagnosed. There have been no reports of surgery for a rectal inflammatory myofibroblastic tumor using transanal total mesorectal excision. We preoperatively diagnosed the patient with an inflammatory myofibroblastic tumor in the lower rectum and achieved anorectal preservation and curative resection with transanal total mesorectal excision, providing good view of the deep pelvis.

Trans-anal surgery with the taTME technique for rectal gastrointestinal stromal tumors: a retrospective study

PURPOSE

Rectal gastrointestinal stromal tumors (GISTs) surgery is often challenging owing to the anatomical constraints of the narrow pelvis and tumor hugeness. Despite the increasing number of patients undergoing trans-anal total mesorectal excision (taTME) globally, the feasibility of trans-anal surgery with the taTME technique for rectal GISTs remains unclear. We aimed to evaluate the feasibility of trans-anal surgery with the taTME technique for rectal GISTs.

METHODS

Using a prospectively collected database, we retrospectively analyzed the clinical findings, surgical outcomes, pathological outcomes, urinary and anal functions, and prognoses of patients who underwent trans-anal surgery with the taTME technique for primary rectal GISTs at the National Cancer Center Hospital East from September 2014 to March 2020.

RESULTS

Twenty-one patients with primary rectal GISTs were included in this study. The median distance from the anal verge to the lower edge of the tumor was 40 mm (range, 15-60 mm), and the median tumor size was 59 mm (range, 11-175 mm). Moreover, seven and 14 patients underwent one-team and two-team surgeries, respectively, with curative intent. Nineteen patients (90.5%) underwent anus-preserving surgery, and the urinary tracts were preserved in all cases. Two-team surgery showed a significantly lower blood loss volume and shorter operation time than one-team surgery (58 vs. 222 mL, P = 0.017; 184 vs 356 min, P = 0.041, respectively). The pathological negative-margin resection rate was 100%. During the follow-up period, no patient developed local GIST recurrence and one (4.8%) developed distant metastasis.

CONCLUSION

Trans-anal surgery with the taTME technique is feasible for rectal GISTs, and two-team surgery may be more advantageous than one-team surgery in terms of operation time and blood loss.

Morphological characteristics of lateral pelvic lymph nodes in locally advanced lower rectal cancer: A retrospective study

AIM

This study aimed to investigate the potential of the size and aspect ratio of metastatic and non-metastatic lateral pelvic lymph nodes (LPLNs) as low-risk markers for locally advanced lower rectal cancer, without treatment by neoadjuvant chemoradiation therapy or LPLN dissection.

METHODS

This single-center, retrospective cohort study evaluated 310 consecutive patients diagnosed with lower rectal cancer (T: T3/T4, N: any, and M: M0) who underwent curative surgery without neoadjuvant therapies between 2010 and 2018. The harvested LPLNs were categorized into groups A (metastasis-positive lymph nodes), B (metastasis-negative lymph nodes in the area bearing metastasis-positive lymph nodes), C (metastasis-negative lymph nodes in a metastasis-negative area in metastasis-positive patients), and D (lymph nodes in non-metastatic patients). The main outcome measure was the relationship among lymph node size, aspect ratio, and metastasis in the LPLNs.

RESULTS

Overall, 3962 LPLNs were harvested. The long and short axes and the aspect ratio were significantly longer and higher, respectively, in group A than in the other groups (P < .001). The aspect ratio in group B was significantly higher than that in groups C and D (P < .001). The aspect ratio in group C was significantly higher than that in group D (P < .001). Furthermore, no metastasis-positive lymph nodes had an aspect ratio of less than 0.4. Metastasis-positive LPLNs tended to be larger and rounder than their metastasis-negative counterparts.

CONCLUSIONS

Metastatic LPLNs in patients with lower rectal cancer are significantly larger and have a higher aspect ratio. Lymph nodes with aspect ratios of <0.4 were metastasis negative.

Anorectal Transplantation: The First Long-term Success in a Canine Model

OBJECTIVE

Anorectal transplantation is a challenging procedure but a promising option for patients with weakened or completely absent anorectal function.

SUMMARY BACKGROUND DATA

We constructed a canine model of anorectal transplantation, evaluated the long-term outcomes, and controlled rejection and infection in allotransplantation.

METHODS

In the pudendal nerve function study, 6 dogs were randomly divided into 2 groups, transection and anastomosis, and were compared with a control using anorectal manometry, electromyography, and histological examination. In the anorectal transplantation model, 4 dogs were assigned to 4 groups: autotransplant, allotransplant with immunosuppression, allotransplant without immunosuppression, and normal control. Long-term function was evaluated by defecography, videography, and histological examination.

RESULTS

In the pudendal nerve function study, anorectal manometry indicated that the anastomosis group recovered partial function 6 months postoperatively. Microscopically, the pudendal nerve and the sphincter muscle regenerated in the anastomosis group. Anorectal transplantation was technically successful with a 3-stage operation: colostomy preparation, anorectal transplantation, and stoma closure. The dog who underwent allotransplantation and immunosuppression had 2 episodes of mild rejection, which were reversed with methylprednisolone and tacrolimus. The dog who underwent allotransplantation without immunosuppression had a severe acute rejection that resulted in graft necrosis. Successful dogs had full defecation control at the end of the study.

CONCLUSIONS

We describe the critical role of the pudendal nerve in anorectal function and the first long-term success with anorectal transplantation in a canine model. This report is a proof-of-concept study for anorectal transplantation as a treatment for patients with an ostomy because of anorectal dysfunction.

Surgical assistant manipulator with diagonal joints and multi-stage telescopic screws for laparoscopic solo surgery

PURPOSE

A surgeon in a sterilized area can perform robotically assisted laparoscopic solo surgery while controlling a laparoscope-holding robot for view stabilization and a forceps robot for pulling organs. At present, no locally operated surgical assistant manipulator with a mechanical remote center of motion (RCM) is available to operate within a small space while providing a wide range of movement. The present study describes a new locally operated detachable end-effector manipulator (LODEM) with diagonal joints and multi-stage telescopic screws.

METHODS

A forceps manipulator attached to commercial surgical forceps was developed. This manipulator uses RCM diagonal joints for the yaw and pitch axes, providing an intuitive pivot point and free rotation, and telescopic nested screws with multiple sliders clamp the commercial forceps for the axis of insertion. The manipulator placed above the abdominal wall using a fixed arm connected to a bed rail is motor controlled by a handheld interface with button switches for precise traction and is controlled manually for easy rough positioning.

RESULTS

Positional accuracy at the tip with a load of 5 N was under 0.5 mm. Mechanical deflection was under 2.1 mm. The manually controlled force was under 4.4 N. Successful simulated laparoscopic cholecystectomy using the prototype manipulator to handle the target and maintain stability was performed on a surgically realistic gallbladder model.

CONCLUSIONS

A LODEM with diagonal joints and multi-stage telescopic screws was developed to facilitate minimally invasive, robotically assisted laparoscopic solo surgery by a surgeon working near the patient. This electric motor-controlled laparoscopic instrument holder by the surgeon in the surgical field could be used for such applications.

Radiologic Factors and Areas of Local Recurrence in Locally Advanced Lower Rectal Cancer After Lateral Pelvic Lymph Node Dissection

BACKGROUND

Identifying preoperative risk factors of local recurrence and patterns of treatment failure resulting after rectal cancer management is important for planning treatment strategies and improving the results of multidisciplinary care.

OBJECTIVE

The purpose of this study was to analyze the associations between the preoperative factors and local recurrence and to investigate the local recurrence areas in patients with locally advanced lower rectal cancer who underwent lateral pelvic lymph node dissection.

DESIGN

The study used a retrospective cohort design.

SETTINGS

It was conducted at a single institution.

PATIENTS

Overall 469 patients with locally advanced lower rectal adenocarcinoma located below the peritoneal reflex who received curative resection with lateral pelvic lymph node dissection during 2010 to 2018 were included.

MAIN OUTCOME MEASURES

Independent risk factors for local recurrence were assessed using multivariate Cox regression. Local recurrence was classified into 3 areas using follow-up images.

RESULTS

A total of 286 patients underwent upfront surgery, 132 patients received neoadjuvant chemotherapy followed by surgery, and 51 patients received preoperative chemoradiotherapy followed by surgery. Eighty-six patients (18.3%) were extramural venous invasion positive, and 113 patients (24.1%) were circumferential resection margin positive. The median follow-up period was 46 months. Local recurrence showed significant association with extramural venous invasion positive (HR = 2.596 (95% CI, 1.321-5.102); p = 0.006) or circumferential resection margin positive (HR = 2.298 (95% CI, 1.158-4.560); p = 0.017). The incidence of local recurrence was observed in 51 patients (10.8%), with the pelvic plexus and internal iliac area being the most frequent (6.6%), followed by the central pelvis area (3.8%), and was markedly low in the obturator area (0.4%).

LIMITATIONS

This was a retrospective, single-institution design.

CONCLUSIONS

Extramural venous invasion status and circumferential resection margin status were associated with a high local recurrence rate in patients who underwent lateral pelvic lymph node dissection. In addition, local recurrence in the obturator area was low compared with that in other areas. See Video Abstract at http://links.lww.com/DCR/B683.

FACTORES RADIOLGICOS Y REAS DE RECURRENCIA LOCAL EN EL CNCER DE RECTO INFERIOR LOCALMENTE AVANZADO DESPUS DE LA DISECCIN GANGLIONAR PLVICA LATERAL

ANTECEDENTES:El identificar los factores de riesgo preoperatorios para recurrencia local y los patrones de fracaso del tratamiento que resultan del manejo del cáncer de recto es importante para planificar las estrategias de tratamiento y mejorar los resultados de la atención multidisciplinaria.OBJETIVO:Analizar las asociaciones entre los factores preoperatorios y la recidiva local, e investigar las áreas de recidiva local en pacientes con cáncer de recto inferior localmente avanzado que se sometieron a disección de ganglios linfáticos pélvicos laterales.DISEÑO:Un diseño de cohorte retrospectivo.ENTORNO CLÍNICO:Una sola institución.PACIENTES:Un total de 469 pacientes con adenocarcinoma rectal inferior localmente avanzado ubicado debajo del reflejo peritoneal que recibieron resección curativa con disección de ganglios linfáticos pélvicos laterales durante 2010-2018.PRINCIPALES MEDIDAS DE RESULTADO:Los factores de riesgo independientes de recurrencia local se evaluaron mediante regresión de Cox multivariante. La recurrencia local se clasificó en 3 áreas utilizando imágenes de seguimiento.RESULTADOS:Doscientos ochenta y seis pacientes se sometieron a cirugía inicial, 132 pacientes recibieron quimioterapia neoadyuvante seguida de cirugía y 51 pacientes recibieron quimiorradioterapia preoperatoria seguida de cirugía. Ochenta y seis pacientes (18,3%) fueron positivos para invasión venosa extramural y 113 pacientes (24,1%) fueron positivos para el margen de resección circunferencial. La mediana del período de seguimiento fue de 46 meses. La recidiva local mostró una asociación significativa con la invasión venosa extramural positiva (cociente de riesgo: 2,596; intervalo de confianza del 95%: 1,321-5,102; p = 0,006) o el margen de resección circunferencial positivo (cociente de riesgo: 2,298; intervalo de confianza del 95%: 1,158-4,560; p = 0,017). La incidencia de recidiva local se observó en 51 pacientes (10,8%), siendo el plexo pélvico y el área ilíaca interna los más frecuentes (6,6%), seguidos del área pélvica central (3,8%), y fue marcadamente baja en el área del obtudador (0.4%).LIMITACIONES:Un diseño retrospectivo de una sola institución.CONCLUSIONES:El estado de invasión venosa extramural o el estado del margen de resección circunferencial se asociaron con una alta tasa de recurrencia local en pacientes que se sometieron a disección de ganglios linfáticos pélvicos laterales. Además, la recurrencia local en el área del obturador fue baja en comparación con la de otras áreas. Consulte Video Resumen en http://links.lww.com/DCR/B683.

A multicentre confirmatory single-arm trial of the safety and efficacy of a transanal drain for prevention of anastomotic leakage after surgery for rectal cancer

AIM

Recent reports have described the use and efficacy of several types of transanal tube (TAT) for preventing anastomotic leakage by reducing intraluminal pressure. The aim of this study was to evaluate the safety and efficacy of a newly developed TAT for the prevention of anastomotic leakage after low anterior resection (LAR) for rectal cancer.

METHOD

A multicentre confirmatory single-arm trial was designed to evaluate the safety and efficacy of a new TAT after LAR for rectal cancer. A total of 115 patients were registered in the trial at several cancer centres and other hospitals. All patients initially received reconstruction with a stapled anastomosis, but 18 then underwent creation of a diverting stoma. Of the remaining 97 patients, the first 96 were included in the protocol-defined primary analysis set. The primary outcome was the incidence of symptomatic leakage and the secondary endpoint was the incidence of complications associated with use of the TAT. The TAT was placed during LAR without creating a covering stoma and the drain was removed 4 or 5 days postoperatively.

RESULTS

The rate of symptomatic leakage was 5.2% (95% confidence interval 1.7-11.7), which was significantly lower than the predetermined threshold value of 15.8% (one-sided p-value 0.0013). Only one patient had Grade 3 rectal bleeding that might have been related to use of the TAT.

CONCLUSION

This nonrandomized study shows that the TAT appears to be safe and results in lower rates of anastomotic leakage in LAR compared with previous studies.

Potential benefit of laparoscopic surgery for rectal cancer on postoperative male sexual function

AIM

The aim of this retrospective study was to evaluate the incidence of male sexual dysfunction after mid to low rectal cancer surgery and to identify factors associated with postoperative erectile and ejaculatory dysfunction.

METHODS

The subjects were 410 consecutive male patients who underwent surgery for mid to low rectal cancer from 2009 to 2015. Two questionnaires on sexual function were administered: the International Index of Erectile Function, and an original questionnaire on ejaculatory status. Erectile and ejaculatory dysfunction were examined before and 3, 6, 12 months after surgery. In patients without preoperative dysfunction, multivariate regression analyses were performed to identify factors associated with the incidence of erectile and ejaculatory dysfunction at 12 months after surgery.

RESULTS

Of 410 patients, 234 (57%) gave complete responses to the questionnaires, of whom 108 (46%) and 155 (66%) had severe erectile dysfunction, while 115 (49%) and 168 (72%) had severe ejaculatory dysfunction before and 12 months after surgery, respectively. Of the patients who maintained sexual function preoperatively, the incidence of erectile and ejaculatory dysfunction at 12 months after surgery was 51% (64/126) and 49% (58/119), respectively. In multivariate analysis, age >60 years (P = 0.02), laparotomy (P = 0.002), and creation of a diverting ileostomy (P = 0.003) were independent factors associated with postoperative erectile dysfunction, while age >60 years (P = 0.005), laparotomy (P = 0.04), and lateral lymph node dissection (P = 0.001) were independent factors associated with postoperative ejaculatory dysfunction.

CONCLUSION

Sexual dysfunction occurred in almost half of patients after rectal cancer surgery, and was independently associated with several factors, including laparotomy.

High expression of TMEM180, a novel tumour marker, is associated with poor survival in stage III colorectal cancer

BACKGROUND

Transmembrane protein 180 (TMEM180) is a newly identified colorectal cancer (CRC)-specific molecule that is expressed very rarely in normal tissue and up-regulated under hypoxic conditions. We developed a monoclonal antibody (mAb) against TMEM180 and decided to examine the medical significance using the mAb.

METHODS

A total of 157 patients (86 men and 71 women; median age 63.0 years) with stage III CRC who underwent curative surgery were analyzed for TMEM180 expression as a retrospective cohort design. Immunohistochemistry with anti-TMEM180 mAb was conducted on frozen sections, and the data were evaluated for any correlation with clinicopathological indices or prognosis. SW480 CRC cells were examined to investigate the relationship between the expression of TMEM180 and tumourigenesis of xenografts.

RESULTS

In total, 92 cases had low TMEM expression and 65 had high TMEM180 expression. For disease-free survival, hazard ratio in high-TMEM180 cases was 1.449 (95% confidential interval = 0.802-2.619) higher than in low-TMEM180 cases, but the difference was not significant (p = 0.219). For cancer specific survival, hazard ratio in high-TMEM180 cases was 3.302 (95% confidential interval = 1.088-10.020), significantly higher than in low-TMEM180 cases (p = 0.035). In an assay examining in vitro colony-forming activity in soft agar, SW480-WT cells clearly formed colonies, but neither KD1 nor KD2 cells did. The in vivo tumour-initiating activity of SW480 cell lines was positively correlated with the level of TMEM180 expression.

CONCLUSION

These results indicate that TMEM180 is a useful marker for clinical prognosis in patients with CRC. We believe that these fundamental data warrant further basic and translational studies of TMEM180, and its mAb, for development of therapeutics against CRC.

Locally operated assistant manipulators with selectable connection system for robotically assisted laparoscopic solo surgery

PURPOSE

By integrating locally operated surgical assistant robots in a sterilized area, a surgeon can perform safe robotically assisted laparoscopic solo surgery while controlling a laparoscope-holding robot and a forceps robot. At present, there is no leader-follower control system with switchable connection for the leader device in which each assistant follower robot can provide the manipulation intuitively and easily. In the present study, a new locally operated leader-follower selectable control system has been developed.

METHODS

The leader-follower system was developed to connect one leader operating device and one of two selectable follower assistant manipulator devices with different numbers of axes, kinematics models, sensors, and actuators for view stabilization and pulling organs. The system is constructed using the middleware of the ORiN-based medical robot architecture MRLink. The system is regulated by the robot integrator application with unilateral leader-follower PTP using the relative displacement between the leader device and the selected follower device through providers of device interface including the information and control commands.

RESULTS

The execution cycle for updating the position was 50 ms, and the time delay to catch up with the same position was 100 ms. Two assistant manipulators controlled by the leader-follower selectable system could successfully produce the desired view and handle the target organ model for 17 min in a simulated laparoscopic cholecystectomy.

CONCLUSIONS

A locally operated leader-follower selectable control system was constructed to facilitate minimally invasive, robotically assisted laparoscopic solo surgery by a doctor working near the patient. This system could be used for such applications.

Sacral neuromodulation for the prevention of a permanent stoma in patients with severe defecation disorder following intersphincteric resection

PURPOSE

Severe defecation disorder occurs frequently in coloanal anastomosis for low rectal cancer, and may affect quality of life. Sacral neuromodulation (SNM) has been reported to be successful after rectal resection, but there are no results for patients treated with intersphincteric resection (ISR).

METHODS

A retrospective single-center study of SNM was performed for patient with defecation disorder following ISR. Pre- and post-treatment bowel frequencies, fecal incontinence episodes, and Wexner, LARS and FIQL scores were assessed to evaluate the efficacy. A good response was defined as ≥ 50% reduction of bowel frequency per day or fecal incontinence episodes per week.

RESULTS

10 patients (7 males, mean age 67.5 years) underwent SNM. All patients had severe fecal incontinence with a median Wexner score of 15 (13-20) and a median LARS score of 41 (36-41). The Wexner score improved after SNM, but not significantly (p = 0.06). LARS and FIQL scores significantly improved after SNM (p = 0.02, p = 0.01). At the end of follow-up, the good response rate was 40%. Three cases without a good response required creation of a permanent stoma.

CONCLUSION

Seven out of 10 patients did not require a permanent colostomy after SNM. SNM should be considered before performing a permanent colostomy.

Association between urinary function and resected pattern of the autonomic nerve system after transanal total mesorectal excision for rectal cancer

AIM

Transanal total mesorectal excision (TaTME) is expected to improve the quality of total mesorectal excision as well as preserve urinary function. We aimed to study the frequency and risk factors of urinary dysfunction in rectal cancer patients after TaTME. Moreover, we analysed the association between urinary function and resected pattern of the autonomic nerve system (ANS) in TaTME.

METHOD

We retrospectively analysed 231 patients who underwent TaTME at our hospital from 2013 to 2018. Independent risk factors for urinary dysfunction were assessed by multivariate analysis. Urinary dysfunction was defined as a condition that requires urethral catheterisation. We intraoperatively judged and classified the preserved or resected pattern of ANS into four categories.

RESULTS

The rate of urinary dysfunction after TaTME was 12.1% at discharge. Multivariate analysis revealed that beyond TME and ANS resection were the two major independent risk factors for urinary dysfunction. Total ANS preservation had reduced rates of urinary dysfunction, and all patients were free from catheterisation 6 months post-surgery. There was a higher rate of urinary dysfunction in total ANS resection than in partial ANS resection at 6 months post-surgery.

CONCLUSION

This study showed that urinary function after TaTME was associated with resection of the ANS. Furthermore, the rate of urinary dysfunction and recovery time were closely related to the pattern of ANS resection.

Evaluating the clinical utility of universal screening to identify Lynch syndrome in stage III/III colorectal cancer patients: A prospective observational study in Japan

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Background: Universal screening for Lynch syndrome (LS) by identifying deficient DNA mismatch repair (MMR) in the tumor tissue of all new colorectal cancer (CRC) patients is widely accepted. The population prevalence of LS is approximately 3% in Western countries, whereas it is approximately 0.7% in Japan. In addition, the number of relatives diagnosed per proband is 3.6 in Western countries, whereas there are even fewer diagnoses per proband in Japan. To address the issue of LS remaining largely underdiagnosed in Japan, we prospectively evaluated the clinical utility of universal screening of LS in CRC patients. Methods: From March 2016 to August 2019, all consecutive new cases of stage II/III CRC underwent immunohistochemistry (IHC) screening for MMR using MLH1, MSH2, MSH6, and PMS2 antibodies. The patients negative for both MLH1 and PMS2 (MLH1-/PMS2-) were subjected to reflex testing for BRAF V600E mutation. Patients with both MLH1-/PMS2- and BRAF negative (cohort A, n = 14) and those with other IHC patterns (cohort B, n = 13) were referred for genetic counseling (GC) and genetic testing (GT). Furthermore, relatives of probands with confirmed LS were referred for GC/GT if they were willing. Results: Overall, 591 pts were enrolled in this study. Patient background were as follows: > 70 y/o, 35%; right-sided/left-sided colon/rectum, 24%/24%/53%; and cStage II/III, 65%/35%. Of 591 patients, 40 (6.8%) had MMR deficiency. Of 27 patients with MLH1-/PMS2-, 24 underwent BRAF reflex testing; only 10 of these patients tested positive for mutation. Of 27 patients recommended for GC, 25 were referred for GC and 22 for GT, which revealed 12 LS cases (2%, mutation genes:MLH1/PMS2/MSH2; 4/2/6). The frequency of LS diagnosis with respect to patient background was as follows: > 70/≤70 y, 1.0/2.6%; right-sided/left-sided colon/rectum, 5.8/0/1.3%; and cStage II/III, 2.6/1.0%. Interestingly, only 3 (25%) of 12 patients who underwent GC/GT in cohort A had LS compared with 9 (90%) of 10 patients in cohort B ( p= 0.004). Moreover, among 11 relatives of 5 families who were willing to undergo GC/GT, six (55%) had LS, of whom two were first-degree relatives (33%), one was a second-degree relative (50%), and three were third-degree relatives (100%). Conclusions: This study showed that universal screening of LS in CRC patients is significantly useful in Japan. Furthermore, implementing a reflex testing strategy demonstrated high adherence to guidelines and the appropriateness of our referrals for GC/GT.

Delorme surgery for colonic mucosal prolapse after intersphincteric resection

PURPOSE

Mucosal prolapse at the site of anastomosis is a long-term complication unique to ISR. It reduces the QOL of patients due to a worsened anal function and local symptoms around the anus. We herein sought to assess the surgical outcomes after Delorme surgery for these patients.

METHODS

ISR was performed in 720 patients with low rectal cancer between January 2001 and March 2019 at the National Cancer Center Hospital East. Among these patients, the 33 (4.5%) who underwent initial Delorme surgery for postoperative colonic mucosal prolapse were identified from the medical records and then were analyzed retrospectively. We estimated the anal function using Wexner's incontinence score and assessed whether local anal symptoms due to the prolapse improved postoperatively.

RESULTS

Stoma closure was performed before Delorme surgery in 15 (45.5%) patients, and we compared the preoperative and postoperative anal function in these patients. The average Wexner's incontinence score changed from 15.1 before to 12.9 after Delorme surgery. Local symptoms around the anus improved in all 33 (100%) patients. Recurrence of colonic mucosal prolapse occurred in 5 patients (15%), and Delorme surgery was reperformed in these cases.

CONCLUSION

Delorme surgery for colonic mucosal prolapse following ISR has clinical benefits for both improving anal local symptoms and slightly improving the anal function.

Forced expression of miR-143 and -145 in cardiomyocytes induces cardiomyopathy with a reductive redox shift

BACKGROUND

Animal model studies show that reductive stress is involved in cardiomyopathy and myopathy, but the exact physiological relevance remains unknown. In addition, the microRNAs miR-143 and miR-145 have been shown to be upregulated in cardiac diseases, but the underlying mechanisms associated with these regulators have yet to be explored.

METHODS

We developed transgenic mouse lines expressing exogenous miR-143 and miR-145 under the control of the alpha-myosin heavy chain (αMHC) promoter/enhancer.

RESULTS

The two transgenic lines showed dilated cardiomyopathy-like characteristics and early lethality with markedly increased expression of miR-143. The expression of hexokinase 2 (HK2), a cardioprotective gene that is a target of miR-143, was strongly suppressed in the transgenic hearts, but the in vitro HK activity and adenosine triphosphate (ATP) content were comparable to those observed in wild-type mice. In addition, transgenic complementation of HK2 expression did not reduce mortality rates. Although HK2 is crucial for the pentose phosphate pathway (PPP) and glycolysis, the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) was unexpectedly higher in the hearts of transgenic mice. The expression of gamma-glutamylcysteine synthetase heavy subunit (γ-GCSc) and the in vitro activity of glutathione reductase (GR) were also higher, suggesting that the recycling of GSH and its de novo biosynthesis were augmented in transgenic hearts. Furthermore, the expression levels of glucose-6-phosphate dehydrogenase (G6PD, a rate-limiting enzyme for the PPP) and p62/SQSTM1 (a potent inducer of glycolysis and glutathione production) were elevated, while p62/SQSTM1 was upregulated at the mRNA level rather than as a result of autophagy inhibition. Consistent with this observation, nuclear factor erythroid-2 related factor 2 (Nrf2), Jun N-terminal kinase (JNK) and inositol-requiring enzyme 1 alpha (IRE1α) were activated, all of which are known to induce p62/SQSTM1 expression.

CONCLUSIONS

Overexpression of miR-143 and miR-145 leads to a unique dilated cardiomyopathy phenotype with a reductive redox shift despite marked downregulation of HK2 expression. Reductive stress may be involved in a wider range of cardiomyopathies than previously thought.

Providing Weight Loss Support to Patients Who Are Obese in Preparation for Colorectal Cancer Surgery to Reduce Surgical Site Infection Risk: A Mixed-methods Study

Obesity increases the risk of surgical site infections (SSIs) after colorectal cancer surgery, but strategies to support weight loss in obese patients who have colorectal cancer have not been established.

PURPOSE

This mixed-methods study, using retrospective and prospective data, aimed to explore inhibitors and facilitators of preoperative weight loss in obese patients with colorectal cancer and the potential impact of preoperative weight loss support on SSIs.

METHODS

Patients with a body mass index (BMI) of ≥ 25 kg/m2 were eligible to participate in the weight loss support program. Patient demographic, history, surgical, and outcomes variables were abstracted from the records. Five (5) nurses who provided weight loss support participated in a focus group interview method to explore weight loss inhibitory and promotional factors. Descriptive statistics and qualitative analysis methods were used to examine the data.

RESULTS

Twenty-six (26) patients participated in the program for a mean of 45.5 days (SD ± 25.3). Body weight decreased from 79.8 kg (SD ± 15.6) to 75.7 kg (SD ± 14.3), and BMI decreased from 30.4 kg/m² (SD ± 4.7) to 29.4 kg/m² (SD ± 5.0) (P < .05). The average weight loss percentage was 4.9% (SD ± 3.4). In 14 patients, the weight loss percentage was 5% or more. SSIs occurred in 5 of 26 patients (19.2%). Additionally, 4 of 26 patients (15.4%) who had 8.8% or more weight loss did not manifest SSIs. Previous weight loss before the preoperative surgery visits, lack of motivation for weight loss, and time and duration required for weight loss were identified as inhibitory factors, whereas history of successful weight loss experience, knowledge acquisition, family support, and reduced knee and lower back pain were identified as promotional factors for weight loss.

CONCLUSION

Patients in this program lost weight prior to colorectal surgery. Research to further explore the safety and effects of preoperative weight loss in obese patients with colorectal cancer as well as inhibitory and promotional factors for participation and success is needed.

Vaticanol C, a phytoalexin, induces apoptosis of leukemia and cancer cells by modulating expression of multiple sphingolipid metabolic enzymes

Resveratrol (RSV) has recently attracted keen interest because of its pleiotropic effects. It exerts a wide range of health-promoting effects. In addition to health-promoting effects, RSV possesses anti-carcinogenic activity. However, a non-physiological concentration is needed to achieve an anti-cancer effect, and its in vivo bioavailability is low. Therefore, the clinical application of phytochemicals requires alternative candidates that induce the desired effects at a lower concentration and with increased bioavailability. We previously reported a low IC₅₀ of vaticanol C (VTC), an RSV tetramer, among 12 RSV derivatives (Ito T. et al, 2003). However, the precise mechanism involved remains to be determined. Here, we screened an in-house chemical library bearing RSV building blocks ranging from dimers to octamers for cytotoxic effects in several leukemia and cancer cell lines and their anti-cancer drug-resistant sublines. Among the compounds, VTC exhibited the highest cytotoxicity, which was partially inhibited by a caspase 3 inhibitor, Z-VAD-FMK. VTC decreased the expression of sphingosine kinase 1, sphingosine kinase 2 and glucosylceramide synthase by transcriptional or post-transcriptional mechanisms, and increased cellular ceramides/dihydroceramides and decreased sphingosine 1-phosphate (S1P). VTC-induced sphingolipid rheostat modulation (the ratio of ceramide/S1P) is thought to be involved in cellular apoptosis. Indeed, exogenous S1P addition modulated VTC cytotoxicity significantly. A combination of SPHK1, SPHK2, and GCS chemical inhibitors induced sphingolipid rheostat modulation, cell growth suppression, and cytotoxicity similar to that of VTC. These results suggest the involvement of sphingolipid metabolism in VTC-induced cytotoxicity, and indicate VTC is a promising prototype for translational research.

Risk factors for parastomal hernia of loop stoma and relationships with other stoma complications in laparoscopic surgery era

Background

Laparoscopic approach is now a widespread technique used worldwide, but there are few recent studies on risk factors for parastomal hernia. Therefore, this study was performed to analyze the incidence of parastomal hernia in laparoscopic and open surgery in which a loop stoma was created and was intended to be temporary, and to determine risk factors for parastomal hernia formation. Associations between parastomal hernia and other stoma-related complications were also analyzed.

Methods

A retrospective analysis of patient and surgical characteristics was performed in 153 consecutive patients who underwent a temporary diverting loop ileostomy or colostomy after surgery related to malignant diseases at our hospital from January to December 2016.

Results

Parastomal hernia developed in 77 cases (50.3%), including 39 (25.5%) diagnosed by physical examination and 38 (24.8%) detected by CT alone. On multivariate analysis, a stoma not passing through the middle of the rectus abdominis muscle was the only independent risk factor for parastomal hernia formation (p = 0.005) during the median follow-up of 245.0 days. When we analyzed the factors that were associated with a stoma not passing through the middle of the rectus abdominis muscle, the only independent factor associated with this misplacement of the stoma was a laparoscopic approach (p = 0.012). An analysis of stoma-related complications showed that peristomal skin disorders were significantly associated with parastomal hernia (p = 0.049).

Conclusions

This study showed that a stoma that is not formed through the middle of the rectus abdominis muscle is a risk factor for parastomal hernia formation, and that a laparoscopic approach is associated with this risk factor. Moreover, parastomal hernia is significantly associated with peristomal skin disorders.

A case of resected retroperitoneal metachronous solitary metastasis from caecal cancer

Colorectal cancer metastasis to the retroperitoneum, especially solitary metastasis allowing curative resection, is rare. We report a case of complete resection of retroperitoneal metachronous solitary metastasis from caecal cancer without distant metastasis. An 80-year-old woman with caecal cancer underwent laparoscopic ileocaecal resection with regional lymph node dissection. According to the eighth edition of the TNM classification, the pathological diagnosis was stage IIA (T3N0M0). Six months following the surgery, computed tomography revealed a solitary mass of 2cm diameter, dorsal to the right kidney. A second procedure for the removal of the tumour was performed. The lesion was pathologically diagnosed as a metachronous solitary retroperitoneal metastasis from caecal cancer. The patient is surviving and free from recurrence 17 months following the second procedure.

Involvement of MCL1, c-myc, and cyclin D2 protein degradation in ponatinib-induced cytotoxicity against T315I(+) Ph+leukemia cells

T315I mutation found in chronic myelogenous leukemia (CML) and Ph + ALL patients is the most serious one among resistance against BCR/ABL kinase inhibitors including imatinib and is only responsive to ponatinib (PNT). However, the novel strategy is required to reduce life-threatening adverse effects of PNT including ischemic cardiovascular disease. We examined the mechanism of PNT-induced cytotoxicity against a T315I(+) Ph + ALL cell line, TccY/Sr. PNT induced apoptosis (increased sub G1 cells, and cleaved caspase3 and PARP), and suppressed protein expression of MCL1, cyclin D2 and c-myc, which were reversed by a proteasome inhibitor, MG132, suggesting enhanced proteasomal degradation by PNT. Among BCL2 family inhibitors, MCL1 inhibitors (maritoclax and AZD5991) robustly induced cell death, showing the MCL1-dependent survival of TccY/Sr cells. Decreased MCL1 and c-myc expression by PNT was also observed in T315I(+) MEGA2/STIR cells. PNT suppressed PI3K activation followed by AKT inhibition and GSK3 dephosphorylation. PI3K/AKT inhibitors mimicked PNT, suggesting that PI3K/AKT signaling is important for survival of TccY/Sr cells. Moreover, GSK3 inhibitor (SB216763) reduced PNT-induced cytotoxicity and degradation of c-myc and MCL1. AZD5991 exhibited the synergistic action with PNT, anti-cancer drugs and venetoclax (BCL2 inhibitor), suggesting the utility of MCL1 inhibitor alone or in combination as a future clinical option for Ph + leukemia patients.

Impact of intraoperative indocyanine green fluorescence angiography on anastomotic leakage after laparoscopic sphincter-sparing surgery for malignant rectal tumors

PURPOSE

Whether indocyanine green fluorescence angiography (ICG-FA) during rectal surgery is effective in reducing anastomotic leakage remains unclear. This study aimed to investigate the effect of intraoperative ICG-FA on anastomotic leakage after sphincter-sparing surgery for malignant rectal tumors.

METHODS

This was a retrospective, single-center cohort study conducted on 852 consecutive patients who underwent laparoscopic sphincter-sparing surgery from January 2007 to June 2017 at our institution. The incidence of anastomotic leakage was compared between patients who underwent ICG-FA to determine the proximal resection margin and those in whom this technique was not performed, using logistic regression analysis, including propensity score.

RESULTS

A total of eight patients were excluded (one patient with previous low anterior resection and seven patients who underwent simultaneous resection for other primary cancers), resulting in 844 patients being analyzed. Before propensity score matching, 141 patients (16.7%) who underwent ICG-FA were compared with 703 patients (83.3%) in whom ICG-FA was not performed. The incidence of anastomotic leakage was 2.8% (4/141) in the ICG-FA group and 12.4% (87/703) in the control group (p = 0.001). After propensity score matching (n = 420), the patient characteristics between the two groups were well balanced, and the incidence of anastomotic leakage was 2.8% (4/141) in the ICG-FA group and 13.6% (38/279) in the control group (p = 0.001). Logistic regression analyses using propensity score showed that patients who underwent ICG-FA had significantly lower odds of anastomotic leakage.

CONCLUSION

Intraoperative ICG-FA is a promising method to reduce anastomotic leakage after laparoscopic rectal surgery.

Prognostic Impact of Curative Resection for Peritoneal Recurrence of Colorectal Cancer

BACKGROUND

Peritoneal recurrence (PR) of colorectal cancer is a poor prognostic factor but may be treatable by curative resection. We investigated the efficacy of this treatment and identified risk factors for postoperative recurrence.

METHODS

The subjects were patients who underwent radical surgery for colorectal cancer between January 2006 and March 2014. Those with PR were retrospectively reviewed. Prognostic factors for overall survival (OS) and risk factors for postoperative recurrence were identified.

RESULTS

Among 2256 patients, 66 had PR (2.9%). Surgical resection of PR was performed in 41 patients. Curative resection was achieved macroscopically in 38 cases without diffuse metastases in the peritoneum distant from the primary tumor and with a peritoneal cancer index < 10. In multivariate analysis, curative resection was a significant prognostic factor [hazard ratio (HR) 0.198] for better 5-year OS compared with cases without curative resection (68.7% vs. 6.3%, P < 0.001). In 28 cases with concurrent metastasis, curative resection significantly improved 5-year OS compared with no curative resection (78.7% vs. 0%, P = 0.008). In the 38 patients with curative resection, the 3-year recurrence-free survival rate was 21.4%. In multivariate analysis, concurrent metastasis was a significant risk factor [HR 3.394] for postoperative recurrence, and cases with concurrent metastasis more frequently had recurrence within 2 years after curative resection.

CONCLUSIONS

Curative resection improved the prognosis in patients with limited and resectable PR of colorectal cancer with or without concurrent metastasis. However, recurrence after curative resection was common and concurrent metastasis was a risk factor for this recurrence.

VOLTAGE-B study: Nivolumab monotherapy and subsequent curative surgery following preoperative chemoradiotherapy in patients with locally recurrent rectal cancer (LRRC) without previous radiotherapy

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Background: Chemoradiotherapy (CRT) followed by curative resection in patients (pts) with local recurrence after radical surgery for primary rectal cancer is the preferred strategy if radiotherapy (RT) was not previously performed. In VOLTAGE-A study, nivolumab plus surgery following CRT showed a promising pathologic complete response (pCR) rate of 30% in pts with microsatellite-stable (MSS) advanced primary rectal cancer. The treatment sequence was prospectively investigated in pts with Locally Recurrent Rectal Cancer (LRRC) in VOLTAGE-B. Methods: Pts with pelvic LRRC without previous RT were included. Five cycles of nivolumab (240 mg q2 weeks) plus curative surgery following CRT (50.4 Gy with capecitabine 1,650 mg/m2) were performed. The pCR rate using AJCC tumor regression grading and curative resection rate were key endpoints. Planned sample size in VOLTAGE-B was set 10 pts in an exploratory manner. Results: From May to Oct 2018, 10 pts were included. Median age was 65 and 8 were male. Curative resection was performed in nine pts with MSS. One had a newly diagnosed supraclavicular lymph node metastasis before surgery. As one pt with AJCC grade 0, seven with grade 2, and one with grade 3, were observed, pCR rate was 10%. As of cut-off date of Apr 2019, three pts showing recurrence out of the nine pts were observed. Nivolumab-related adverse events (AEs) were only one pt with grade 1 hyperthyroidism and one with grade 1 erythema. Grade 3/4 surgery-related AEs were observed in six pts, including two pts with ileus and two with pelvic infections. No treatment-related deaths were observed. Conclusions: The pCR rate of 10% with acceptable toxicity was shown in MSS LRRC pts treated with nivolumab plus curative surgery following CRT. Translational research exploring better predictors of efficacies of study treatment are ongoing. Clinical trial information: NCT02948348.

Ki67 expression and localization of T cells after neoadjuvant therapies as reliable predictive markers in rectal cancer

Chemoradiotherapy (CRT) is the standard neoadjuvant therapy for locally advanced rectal cancer (RC). However, neoadjuvant chemotherapy (NAC) also shows favorable outcomes. Although the immunological environment of RC has been thoroughly discussed, the effect of NAC on it is less clear. Here, we investigated the immunological microenvironment, including T cell infiltration, activation, and topological distribution, of resected RC tissue after neoadjuvant therapies and evaluated the correlation between T cell subsets and patient prognosis. Rectal cancer patients (n = 188) were enrolled and categorized into 3 groups, namely CRT (n = 41), NAC (n = 46), and control (surgery alone; n = 101) groups. Characterization of residual carcinoma cells and T cell subsets in resected tissues was performed using multiplex fluorescence immunohistochemistry. The densities of total and activated (Ki67^high) T cells in tissues after NAC, but not CRT, were higher than in control. In both CRT and NAC groups, patients presenting with higher treatment effects showed aggressive infiltration of T cell subsets into carcinomas. Multivariate analyses of pathological and immunological features and prognosis revealed that carcinoma Ki67^highCD4⁺ T cells after CRT and stromal Ki67^highCD8⁺ T cells after NAC are important prognostic factors, respectively. Our results suggest that evaluation of T cell activation with Ki67 expression and its tumor localization can be used to determine the prognosis of advanced RC after neoadjuvant therapies.

Recurrence of rectal anastomotic leakage following stoma closure: assessment of risk factors

AIM

In patients with a previous history of rectal anastomotic leakage (AL), the surgical indications and timing for closure of a diverting stoma have to be carefully judged. Even if AL has apparently healed before stoma closure, re-leakage may occur after closure. The aim of this study was to determine the incidence and risk factors for recurrent AL following stoma closure. We also examined the treatment strategies aiming to minimize the risk of recurrent AL.

METHODS

From January 2009 to December 2016, 1008 patients underwent sphincter-saving surgery [low anterior resection, all-sphincter-preserving rectal resection with hand-sewn coloanal anastomosis (CAA) and intersphincteric resection (ISR)] for primary rectal cancer with curative intent at our hospital. A total of 69 patients with AL with a Clavien-Dindo Grade III or more who subsequently underwent closure of a diverting stoma were retrospectively reviewed for this study.

RESULTS

The incidence of recurrent leakage after stoma closure in this series was 13% overall with an incidence of 25% in the CAA/ISR group and 5% in the low anterior resection group. Significant risk factors included hand-sewn anastomosis (P = 0.0257) compared to stapled anastomosis, ischaemia at the anastomotic site as the cause of initial AL (P < 0.001) and a shorter interval between confirmation of healing and stoma closure (P = 0.00952).

CONCLUSION

Ischaemia at the anastomotic site was the main risk factor for recurrent leakage, particularly after CAA/ISR. Additional treatment options before stoma closure should be considered to avoid re-leakage in such cases.

Genome-wide association study and whole-genome sequencing identify a deletion in LRIT3 associated with canine congenital stationary night blindness

Congenital stationary night blindness (CSNB), in the complete form, is caused by dysfunctions in ON-bipolar cells (ON-BCs) which are secondary neurons of the retina. We describe the first disease causative variant associated with CSNB in the dog. A genome-wide association study using 12 cases and 11 controls from a research colony determined a 4.6 Mb locus on canine chromosome 32. Subsequent whole-genome sequencing identified a 1 bp deletion in LRIT3 segregating with CSNB. The canine mutant LRIT3 gives rise to a truncated protein with unaltered subcellular expression in vitro. Genetic variants in LRIT3 have been associated with CSNB in patients although there is limited evidence regarding its apparently critical function in the mGluR6 pathway in ON-BCs. We determine that in the canine CSNB retina, the mutant LRIT3 is correctly localized to the region correlating with the ON-BC dendritic tips, albeit with reduced immunolabelling. The LRIT3-CSNB canine model has direct translational potential enabling studies to help understand the CSNB pathogenesis as well as to develop new therapies targeting the secondary neurons of the retina.

Long-Term Outcomes and Lymph Node Metastasis in Patients Receiving Radical Surgery for Pathological T1 Lower Rectal Cancer

BACKGROUND

Few reports have evaluated the long-term outcomes of pathological T1 (pT1) lower rectal cancer (LRC), perhaps because pT1 LRC is classified as TNM stage I if lymph node metastasis (LNM) is absent and stage IIIA if LNM is present. Moreover, it is difficult to diagnose regional LNM preoperatively. This study aimed to clarify the long-term outcomes of radical surgery for pT1 LRC and risk factor(s) for LNM. Additionally, we examined whether preoperative computed tomography (CT) and magnetic resonance imaging (MRI) findings were predictive of LNM in pT1 LRC.

METHODS

This was a retrospective analysis of the clinical characteristics, short-term operative outcomes, and long-term survival rates of 155 patients who received radical surgery and were diagnosed with pT1 LRC at our hospital between January 1993 and February 2017.

RESULTS

Among patients with pT1 LRC, 5-year recurrence-free and overall survival rates were 94.0% and 95.8%, respectively. LNM status was not associated with statistically significant differences in recurrence-free or overall survival. Even in patients with LNM, the recurrence rate was only 9%. Among patients who lacked visible mesorectal lymph nodes on preoperative CT and MRI, LNM rates were 3.5% and 4.3%, respectively.

CONCLUSION

The long-term outcomes after radical surgery for pT1 LRC are satisfactory or good, regardless of the presence or absence of LNM. In patients with pT1 LRC, the absence of visible mesorectal lymph nodes on preoperative CT and MRI is associated with a reduced likelihood of LNM and has a high negative predictive value for LNM.

Resection of the urinary bladder for locally advanced colorectal cancer: a retrospective comparison of partial versus total cystectomy

Background

The postoperative and survival outcomes of patients with primary advanced colorectal cancer who undergo partial versus total cystectomy have not been adequately compared, as studies of this topic are rare and comprise relatively small cohorts. This study aimed to investigate the short- and long-term outcomes of patients who underwent en bloc partial or total cystectomy for primary advanced colorectal cancer that was suspected of adhering to or invading the urinary bladder.

Methods

The study included 90 patients who underwent various degrees of cystectomy between 1993 and 2013 to treat locally advanced primary colorectal cancer that was suspected of involving the urinary bladder. Patients in whom total cystectomy was performed solely because of prostate-invading lower rectal cancer were excluded. Data on patient characteristics and their short- and long-term outcomes were collected retrospectively to evaluate differences between partial cystectomy (the P group; n = 72) and total cystectomy (the T group; n = 18). Postoperative and oncologic outcomes were also analyzed.

Results

The T group had significantly greater operating times than the P group (median, 572 vs. 346 min); blood loss volume was also greater in the T group (median, 3092 vs. 1112 mL). The postoperative overall complication rate was significantly greater in the T group than in the P group (94.4% vs. 51.4%). With a median follow-up duration of 62 months, local recurrences were observed in 22.2 and 6.9% of patients in the T and P groups, respectively. On multivariate Cox regression analyses using partial cystectomy as the reference, total cystectomy was independently associated with poorer local recurrence-free survival (hazard ratio [HR], 4.0 95% confidence interval [CI], 1.1–15.0), relapse-free survival (HR, 2.9; 95% CI, 1.2–6.9), and overall survival (HR, 2.1; 95% CI, 1.0–4.3).

Conclusions

Patients who undergo en bloc total cystectomy for locally advanced colorectal cancers have worse postoperative and oncologic outcomes than those who undergo partial cystectomy.

Voltage: Investigator-initiated clinical trial of nivolumab monotherapy and subsequent radical surgery following preoperative chemoradiotherapy in patients with microsatellite stable locally advanced rectal cancer

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Background: Chemoradiotherapy (CRT) with surgery (S) is standard for patients (pts) with locally-advanced rectal cancer (LARC), and nivolumab (nivo) is active in microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). We studied nivo and radical S following CRT (50.4 Gy with capecitabine 1,650 mg/m2) in T3–4 NanyM0 LARC. Methods: Phase I included testing of a recommended phase II dosing schedule (RP2S). Efficacy and safety were studied in phase II pts and those given RP2S in phase I. In Cohort A-1, for microsatellite stable (MSS) LARC pts, the primary endpoint was centrally confirmed pathologic complete response (pCR) rate using AJCC tumor regression grading. The estimated required sample size assuming null and alternative hypotheses pCR = 10% and 30% was 37 pts, with a 1-sided alpha of 5% and power of 90%. Cohort A-2 was exploratory and included a maximum of 5 MSI-H pts. Results: Nivo 240 mg q2 weeks x 5 cycles, following CRT but pre-S, was the RP2S. From 1/17 to 6/18, 37 pts were enrolled in Cohort A-1. Eleven pts (30%; 90% CI 18-44%) showed pCR (AJCC grade (gr) 0). Including the 3 pts (8%) graded AJCC 1, 14 (38%) had major pathologic responses. In addition, clinical CR was observed in 1 pt (3%) refusing S after nivo. Both MSI-H LARC Cohort A-2 pts showed pCRs. Immune-related severe adverse events were observed in 2 pts (gr 3 myasthenia and gr 2 interstitial nephritis); both fully recovered and had S. No treatment-related deaths were observed. pCR rates of 60% (6/10) and 19% (5/27) (p = 0.038, Fisher exact test) were seen in pts with tumor cells with PD-L1 ≥1% and < 1% IHC staining, respectively, performed on biopsy samples taken pre-CRT. Rates of 62% (8/13) and 10% (1/10) (p = 0.029) were seen in 23 pts with samples analyzable by flow cytometry, according to CD8+ lymphocyte /regulatory T cell (CD8/Treg) ratios ≥2 and < 2, respectively. Conclusions: A promising pCR rate of 30%, with mild toxicity, was shown in MSS LARC pts treated with nivo plus radical S. PD-L1 expression and elevated CD8/Treg ratio may be better predictors of nivo benefit, warranting further study in a larger cohort. Clinical trial information: NCT02948348.

Clinical benefit of high resolution anorectal manometry for the evaluation of anal function after intersphincteric resection

AIM

Intersphincteric resection (ISR) is an advanced anus-preserving operation for treating low rectal cancer while avoiding colostomy. High-resolution anorectal manometry (HR-ARM) allows objective and accurate evaluation of anal function. However, correlations between anal function after ISR and HR-ARM parameters are unknown. The aim of the study was to evaluate HR-ARM for objective evaluation of anal function after ISR.

METHOD

A total of 81 patients who underwent ISR at our hospital between October 2014 and March 2016 were identified from our prospectively collected database and electronic medical records. Of these, 68 patients who had been evaluated using HR-ARM both before and after ISR were included in the study. Faecal incontinence (FI) was assessed by Wexner score. Multivariate analysis was performed to determine risk factors for severe FI after ISR.

RESULTS

Maximum resting pressure (MRP) (P < 0.001) and maximum squeeze pressure (P = 0.04) were significantly lower after ISR, and MRP (P < 0.001) and maximum squeeze pressure (P = 0.02) were significantly lower after total (or subtotal) ISR than after partial ISR. The overall incidence of severe FI after ISR was 18% (12/68), and a high pressure zone before ISR ≤ 3 cm (P = 0.007) and MRP before ISR > 60 mmHg (P = 0.02) were independently associated with an elevated incidence of severe FI after ISR. Decreased preoperative MRP also correlated with severe FI after ISR (P = 0.008).

CONCLUSION

HR-ARM is reliable for the evaluation of anal function after ISR, and the high pressure zone and MRP may be useful preoperative predictors of severe FI after ISR.

Effect of preoperative chemotherapy on distal spread of low rectal cancer located close to the anus

PURPOSE

This study aimed to clarify the frequency of distal spread and the optimal distal margin after preoperative chemotherapy for advanced low rectal cancer.

METHODS

The study included patients with advanced lower rectal cancer who received preoperative chemotherapy and underwent surgery during 2012-2015. We investigated the distal spread of tumor cells, defined as the distal distance from the intramucosal distal tumor edge to the farthest tumor cells located under the submucosal layer. Clinical characteristics were compared for distal spreads ≥ 10 and < 10 mm, and risk factors for distal spread ≥ 10 mm were investigated.

RESULTS

Of the 71 patients, 42 (59%) showed distal spread. Distal spreads of 1-9, 10-19, and ≥ 20 mm were observed in 27 (38%), 11 (15%), and 4 (6%) patients, respectively. Multivariate analysis revealed two independent risk factors for distal spread ≥ 10 mm after preoperative chemotherapy. The first risk factor is the presence of different therapeutic effects between the mucosal and deeper layers (meaning that superficial tumor shrinkage was evident on colonoscopy, but little tumor shrinkage was evident on magnetic resonance imaging) (odds ratio, 11.6; 95% CI, 2.22-61.3). The second risk factor is poorly differentiated or mucinous adenocarcinoma (odds ratio, 8.86; 95% CI, 1.58-49.9).

CONCLUSION

A distal margin of 20 mm is required (10 mm is insufficient) for advanced lower rectal cancer patients who receive preoperative chemotherapy followed by surgery. Independent risk factors for distal spread ≥ 10 mm include (1) the presence of different therapeutic effects between mucosal and deeper layers and (2) poorly differentiated or mucinous adenocarcinomas.

A new method for evaluating joint position sense using oral instructions based on body schema

[Purpose] This study investigated the efficacy of our independently developed method for measuring shoulder joint position sense using oral instructions based on body schema ("schema method") and investigated age-related changes. [Participants and Methods] Forty university students, 19 elderly individuals, and 16 elementary school students were included. Active shoulder abduction was measured in an upright sitting position. Target angles for position sense measurement were 45° of abduction (Target 45) and 90° of abduction (Target 90). The schema method consisted of indicating the target angles through oral instructions alone. The reproduction method and the imitation method were also used to measure angles. Abduction angle, absolute error, and variable error were calculated. [Results] A significant difference in abduction angle at Target 45 was observed between the schema method and the reproduction and imitation methods; no significant differences were observed at Target 90. No significant differences in variable error at Target 90 were observed among the three measurement methods. A significant difference in abduction angle was observed between university students and elderly individuals, and a significant difference in variable error was observed between elementary school students and elderly individuals. [Conclusion] Our body schema-based oral instruction method will be useful for evaluating joint position sense or proprioception.

Preventive effect of diverting stoma on anastomotic leakage after laparoscopic low anterior resection with double stapling technique reconstruction applied based on risk stratification

INTRODUCTION

During laparoscopic low anterior resection with double stapling technique reconstruction, it is necessary to securely implement rectal transection and anastomosis to prevent anastomotic leakage (AL). However, risk factors and preventive measures for AL are not known sufficiently. Therefore, this study aimed to elucidate risk factors associated with AL and to clarify strategies to prevent it.

METHODS

We analyzed a total of 296 cases with rectal cancer who had undergone laparoscopic low anterior resection with double stapling technique reconstruction at the National Cancer Center Hospital East. The relationship between AL and patient, tumor, and treatment characteristics were retrospectively investigated.

RESULTS

There were 186 male and 110 female patients with a median age of 62. Overall, AL occurred in 24 cases (8.1%). Being a man, having an anal verge distance ≤7 cm, and undergoing neoadjuvant chemotherapy were associated with an elevated risk for AL (P = 0.0005, 0.0034, and 0.0222, respectively). Neither an anal drainage tube nor diverting stoma creation correlated with incidence of AL. Multivariate analysis demonstrated that being a man (odds ratio = 18.0; 95% confidence interval: 2.4-138) and having an anal verge distance ≤7 cm (odds ratio = 3.8; 95% confidence interval: 1.5-9.4) were significant risk factors. These two factors were present in 61 cases, including 14 who developed AL (23.0%). In this high-risk group, diverting stoma creation significantly reduced the occurrence of AL (P = 0.0363), but an anal drainage tube had no effect on incidence of AL (P = 0.3399).

CONCLUSION

We identified the high-risk population for AL after laparoscopic low anterior resection with double stapling technique reconstruction based on two factors. This will enable surgeons to appropriately recommend diverting stoma creation.

A Rare Complication After Laparoscopic Lateral Lymph Node Dissection for Rectal Cancer: Two Case Reports of Internal Hernia Below the Superior Vesical Artery

Total mesorectal excision or mesorectal excision with lateral lymph node dissection (LLND) is a standard treatment for locally advanced lower rectal cancer in Japan. Although laparoscopic LLND for rectal cancer is technically complex and challenging, previous studies have demonstrated its feasibility, and the procedure is gradually becoming more common. With this increased use, the incidence of new complications specific to laparoscopic LLND is likely to increase, and a greater awareness of these complications is required. Here we report two cases of internal hernia of the small bowel through an orifice of the vesicohypogastric fascia below the superior vesical artery after laparoscopic LLND. There are six previous reports of internal hernia underneath the pelvic blood vessel after pelvic lymph node dissection for urological or gynecological malignancies, but our cases are the first two that occurred after LLND for rectal cancer. Almost all cases, including our two cases, occurred after laparoscopic surgery and required resection of an incarcerated small bowel. Therefore, the incidence of this complication is likely to increase as the number of cases treated with laparoscopic LLND increases. Our cases show that it is important to perform an emergency operation promptly instead of conservative treatment.

A standing posture support device that reduces laparoscopic surgeons' occupational lower limb stress

BACKGROUND

We developed a surgical knee rest (SKR) that can be used to decrease the stress placed on the lower half of the body when surgeons work in the standing position. We tested the effectiveness of this device in the context of laparoscopic surgery.

MATERIAL AND METHODS

Five healthy, right-handed male surgeons participated, and we recorded surface electromyography (sEMG) signals from the two heads of the left and right gastrocnemius (Gc) muscles during laparoscopic resections of colorectal cancer. The outcome variable was the percentage of maximum Gc muscle effort generated, reported as percent maximal isometric voluntary contraction (%MVC), and this variable was compared between surgeries performed with and without use of the SKR. Assessment covered the first 100 min of surgery, subdivided into two 50-min periods.

RESULTS

Mean %MVC of the left Gc muscle for the full 100-min test period was significantly decreased when the SKR was used (p = .027, vs. SKR not used). Notably, mean %MVC of both Gc muscles was significantly decreased during the first 50 min of surgery (p = .008 and p = .0046).

CONCLUSION

The SKR is useful for decreasing physical stress incurred by laparoscopic surgeons when working in the standing position.