Extended pelvic resection for rectal and anal canal tumors is a significant risk factor for perineal wound infection: a retrospective cohort study

PURPOSE

Perineal wound infection (PWI) rates are high after abdominoperineal resection (APR) and total pelvic exenteration (TPE). This study identified risk factors for PWI after surgery for anorectal tumors and examined the relationship between the surgical excision volume with the PWI degree.

METHODS

A retrospective review involving 135 patients who underwent surgical excision of anorectal tumors was performed. Superficial PWI included cellulitis and superficial dehiscence; deep PWI included major dehiscence, perineal abscess, and presacral abscess. The adjacent organ resection type was classified according to the dead space size formed by surgical excision.

RESULTS

Of the 135 patients, 119 underwent APR, and 16 underwent TPE. PWI occurred in 75 patients (superficial PWI, 44; deep PWI, 31). Adjacent organ resection was an independent risk factor for PWI. The cases with adjacent organ resection were classified into small-defect APR, large-defect APR, and TPE. Large-defect APR and TPE cases had significantly higher rates of deep PWI than APR cases without adjacent organ resection.

CONCLUSIONS

Adjacent organ resection involving the removal of one or more organs and that involving wide-range muscle resection are strong risk factors for deep PWI.

Surgical outcomes of robot-assisted rectal cancer surgery using the da Vinci Surgical System: a multi-center pilot Phase II study

Introduction

We conducted a multi-center pilot Phase II study to examine the safety of robotic rectal cancer surgery performed using the da Vinci Surgical System during the introduction period of robotic rectal surgery at two institutes based on surgical outcomes.

Methods

This study was conducted with a prospective, multi-center, single-arm, open-label design to assess the safety and feasibility of robotic surgery for rectal cancer (da Vinci Surgical System). The primary endpoint was the rate of adverse events during and after robotic surgery. The secondary endpoint was the completion rate of robotic surgery.

Results

Between April 2014 and July 2016, 50 patients were enrolled in this study. Of these, 10 (20%) had rectosigmoid cancer, 17 (34%) had upper rectal cancer, and 23 (46%) had lower rectal cancer; six underwent high anterior resection, 32 underwent low anterior resection, 11 underwent intersphincteric resection, and one underwent abdominoperineal resection. Pathological stages were Stage 0 in 1 patient, Stage I in 28 patients, Stage II in 7 patients and Stage III in 14 patients. Pathologically complete resection was achieved in all patients. There was no intraoperative organ damage or postoperative mortality. Eight (16%) patients developed complications of all grades, of which 2 (4%) were Grade 3 or higher, including anastomotic leakage (2%) and conversion to open surgery (2%).

Conclusion

The present study demonstrates the feasibility and safety of robotic rectal cancer surgery, as reflected by low morbidity and low conversion rates, during the introduction period.

VOLTAGE: Multicenter phase 1b/II study of nivolumab monotherapy and subsequent radical surgery after preoperative chemoradiotherapy with capecitabine in patients with locally advanced rectal cancer

TPS878

Background: Fluoropyrimidine-based chemoradiotherapy (CRT) and subsequent radical surgery (SRS) are widely accepted as standard treatment for patients (pts) with locally advanced rectal cancer (LARC). Pathological complete remission (pCR) rates are associated with improved clinical outcomes. An important target, high-frequency microsatellite instability (MSI-H), was identified for which anti-PD-1 antibodies confirmed robust antitumor activity in metastatic colorectal cancer (mCRC). Recently, improved therapeutic effects by combining an immune checkpoint inhibitor with radiotherapy (RT) have been reported in pts with other cancer types. Furthermore, sequential use of an anti-PD-1 antibody after RT has demonstrated synergistic effects in in vivo models. The purpose of this study is to investigate safety, efficacy, and proof-of-concept (POC) of nivolumab (Nivo) monotherapy plus SRS after pre-CRT in non-MSI-H and MSI-H pts with LARC. Methods: The inclusion criteria are: LARC in the lower/middle rectum; clinical stage, T3–4 N-any M0; age ≥20 years; and 50.4 Gy of concurrent pre-CRT completed with daily 1,650 mg/m2 of capecitabine. Within 2 weeks after pre-CRT, 240 mg of Nivo is administered every 2 weeks 5 times before SRS, which is performed at least 2 weeks after Nivo treatment. The purpose of P1b is to evaluate dose-limiting toxicity and determine the recommended P2 dose (RP2D). In P2, the efficacy and safety of Nivo at RP2D are evaluated. The primary endpoint is the pCR rate by independent central assessment in pts with non-MSI-H LARC. Secondary endpoints include disease-free and overall survival and adverse events. Fifty pts including 40 non-MSI-H and 10 MSI-H pts will be enrolled. As an exploratory biomarker study, repeated biopsies from primary sites and blood collections will be performed 4 times during the treatment courses (before and after pre-CRT, during Nivo treatment, and at SRS), and phenotypes of immune-competent cells, neoantigens, T cell receptor repertoire, and enteric bacteria will be evaluated. As of September 2017, P1b has been completed and P2 is ongoing. Clinical trial information: NCT02948348.

The Impact of Anastomotic Leakage on Anal Function Following Intersphincteric Resection

BACKGROUND

Data regarding anastomotic leakage (AL) following intersphincteric resection (ISR) are lacking. We aimed to evaluate the effect of AL on anal function in a retrospective review of patients who developed AL following ISR.

METHODS

We evaluated 341 consecutive patients who underwent ISR between 2000 and 2012. Patients were classified into three groups: anastomotic dehiscence (AD), major AL (Clavien-Dindo grade III+), or control (<grade III or no AL). Functional assessment was performed at 3, 6, 12, and 24 months after defecation through the preserved anus, and the Wexner score was calculated.

RESULTS

Among patients who underwent ISR for low rectal cancer (anal verge, 3.7 ± 1.3 cm), 59 (17%) developed AL. Of these, 13 patients were classified as AD and 36 as major AL. The rate of the 3-year stomal reversal was significantly lower in the major AL (78.6%) and AD groups (61.5%) than in the control group (88.7%; p < 0.01). Furthermore, the anastomotic stricture rate was higher in the AL and AD groups than in the controls (16.7 and 38.5 vs. 1.8%, respectively; p < 0.01). Wexner scores in the major AL group were poor during the early period, but were similar to the control group at the 2-year follow-up. In contrast, Wexner scores in the AD group remained high, even after 2 years.

CONCLUSIONS

Patients with major AL following ISR had poor anal function that recovered over 2 years, as long as AD was not present. These findings suggest that patients with major AL require a long-term follow-up for anal function.

Image recognition of triangular tissue of an organ pulled by forceps in surgical working area for laparoscope robot

An image processing method using selected corner points and ridge lines to recognize triangular tissue of an organ pulled by forceps in a laparoscopic view has been developed. The proposed method could be used for semi-automatic control of a laparoscope robot. It makes use of a masking process based on the recognition of the forceps and clots, detection of corner points for a Delaunay diagram, detection of ridge lines oriented in the same direction, and recognition of the triangular working area. Triangles recognized in laparoscopic surgical videos using this method were similar to the correct triangles made by an endoscopic specialist.

Compact forceps manipulator with a spherical-coordinate linear and circular telescopic rail mechanism for endoscopic surgery

PURPOSE

By integrating locally operated small surgical robots in a sterilized area, a surgeon can perform safe and accurate robotically assisted laparoscopic surgery. At present, there is no locally operated compact forceps robot that can operate within a small space while providing a wide working area on the abdominal wall. In the present study, a new spherical-coordinate manipulator with a linear telescopic rail and two circular telescopic rails that can act as a third arm for the surgeon has been developed.

METHODS

A compact locally operated detachable end-effector manipulator (LODEM) was developed. This manipulator uses circular telescopic rails with linkage mechanisms for the yaw and pitch axes, and a linear telescopic rail for the insertion/extraction axis is attached to forceps. The dimensions of the manipulator are [Formula: see text] when contracted and [Formula: see text] when expanded. The positional accuracy, mechanical deflection, and backlash of the prototype were evaluated while performing simulated in vivo laparoscopic surgery.

RESULTS

The positional accuracy, deflection, and backlash of the telescopic rail mechanism were 2.1, 1.8, and 5.1 mm, respectively. The manipulator could successfully handle the target and maintain stability, while the arms of the endoscope specialist were free from collisions with the manipulator during an in vivo laparoscopic surgery.

CONCLUSIONS

A compact LODEM was designed to facilitate minimally invasive, robotically assisted laparoscopic surgery by a doctor working near the patient. This device could be used for such applications.

Modulation of the sphingolipid rheostat is involved in paclitaxel resistance of the human prostate cancer cell line PC3-PR

Taxoids are anti-cancer drugs frequently used to treat solid tumors, but they are sometimes ineffective and tumors may become resistant to their action. Here, we examined the involvement of sphingolipid metabolic enzymes in paclitaxel (PTX) resistance using a human prostate cancer cell line, PC3, and its PTX-resistant subline, PC3-PR. PTX (20 nM) suppressed cell proliferation and increased various ceramide species in PC3, but not PC3-PR, cells. PC3-PR contained higher S1P levels than did PC3, regardless of PTX treatment. Western blotting revealed that PC3-PR cells expressed higher levels of sphingosine kinase 1 (SPHK1) and glucosylceramide synthase (GCS) but lower levels of acid sphingomyelinase (ASMase) and neutral sphingomyelinase 2 than did PC3 cells. Inhibition of SPHK1 using siRNA or a pharmacological inhibitor decreased S1P levels in PC3-PR cells and inhibited proliferation in the presence or absence of PTX, suggesting that SPHK1 is at least partially responsible for PTX resistance. Similarly, GCS inhibitors (PDMP and PPMP) increased cellular ceramides and suppressed the proliferation of PC3-PR. However, inhibition of proteasome function or histone deacetylase activity increased SMase and ceramide levels and suppressed PC3-PR proliferation. These results suggest that modulation of metabolic enzyme expression and alteration of the sphingolipid rheostat protects cancer cells against PTX.

Anal Function after Surgery for Low-Lying Rectal Cancer: Comparison of Mechanical and Hand-Sewn Coloanal Anastomosis

BACKGROUND/AIMS

Mechanical coloanal anastomosis (MCAA) or hand-sewn coloanal anastomosis (HCAA) are used in anus-preserving surgery for low-lying rectal cancer. Either method can be used if the lower edge of the tumor is 4-6 cm from the anal verge. The goal of this study was to evaluate differences in the anal function after MCAA or HCAA.

METHODS

The subjects were 305 consecutive patients with primary rectal cancer tumors situated 4-6 cm from the anal verge who underwent curative anus-preserving surgery between 2004 and 2013. Functional assessment was performed using a questionnaire at 3, 6, 12, and 24 months after stoma closure.

RESULTS

Of the 305 patients, 145 underwent MCAA and 160 underwent HCAA. The median distance of the tumor from the anal verge was 6.0 cm (range 4.0-6.0) in the MCAA group and 4.5 cm (range 4.0-6.0) in the HCAA group (p < 0.001). A total of 192 patients (73%) responded to the 1-year questionnaire. The median Wexner score was 6 (range 0-17) in the MCAA group and 11 (range 0-20) in the HCAA group (p < 0.001).

CONCLUSIONS

Retention of anal function is feasible after both MCAA and HCAA. MCAA may contribute to better postoperative anal function compared to HCAA.

Association between pathologic features of peripheral nerves and postoperative anal function after neoadjuvant therapy for low rectal cancer

PURPOSE

Neoadjuvant chemoradiotherapy (CRT) for rectal cancer improves local control but also induces severe postoperative anal dysfunction that may be related to neural degeneration. The aims of the study were to identify pathological features of neural degeneration caused by neoadjuvant CRT or neoadjuvant chemotherapy (NAC) and to evaluate the association between neural degeneration and anal function.

METHODS

A retrospective study using chronologically different groups was performed in 95 patients with rectal cancer treated with curative resection with neoadjuvant CRT (n = 47), NAC (n = 27), or surgery alone (no neoadjuvant therapy) (n = 21) at National Cancer Center Hospital East from 2001 to 2014. Peripheral nerve degeneration was evaluated histopathologically using H&E stained sections, based on karyopyknosis, vacuolar or acidophilic degeneration, denucleation, adventitial neuron change, and fibrosis. Morphological analysis of peripheral nerves was compared among the three groups. The association between pathological features and anal function (Wexner Score) was evaluated.

RESULTS

After CRT, the degree of fibrosis around the tumor was severe, and neural degeneration was found in peripheral neurons. With NAC and surgery alone, there was little fibrosis and neural degeneration. Pathological changes after CRT were more pronounced than those after NAC, indicating greater tissue degeneration due to CRT. There was an association between anal function and degeneration score in the CRT group, but not in the other groups.

CONCLUSIONS

Peripheral nerves in patients who received neoadjuvant CRT showed characteristic pathological features indicating greater degeneration, compared with patients who received NAC. Neural degeneration is associated with anal function and several pathological factors after CRT.

Relationship between tissue tension and thermal diffusion to peripheral tissue using an energy device

The aim of the study was to assess the relationship between tissue tension and thermal diffusion to peripheral tissues using an electric scalpel, ultrasonically activated device, or a bipolar sealing system. The mesentery of pigs was excised with each energy device (ED) at three tissue tensions (0, 300, 600 g). The excision time and thermal diffusion area were monitored with thermography, measured for each ED, and then histologically examined. Correlations between tissue tension and thermal diffusion area were examined. The excision time was inversely correlated with tissue tension for all ED (electric scalpel, r = 0.718; ultrasonically activated device, r = 0.949; bipolar sealing system, r = 0.843), and tissue tension was inversely correlated with the thermal diffusion area with the electric scalpel (r = 0.718) and bipolar sealing system (r = 0.869). Histopathologically, limited deep thermal denaturation occurred at a tension of 600 g with all ED. We conclude that thermal damage can be avoided with adequate tissue tension when any ED is used.

Malondialdehyde induces autophagy dysfunction and VEGF secretion in the retinal pigment epithelium in age-related macular degeneration

Age-related macular degeneration (AMD) is a major cause of blindness in developed countries and is closely related to oxidative stress, which leads to lipid peroxidation. Malondialdehyde (MDA) is a major byproduct of polyunsaturated fatty acid (PUFA) peroxidation. Increased levels of MDA have been reported in eyes of AMD patients. However, little is known about the direct relationship between MDA and AMD. Here we show the biological importance of MDA in AMD pathogenesis. We first confirmed that MDA levels were significantly increased in eyes of AMD patients. In ARPE-19 cells, a human retinal pigment epithelial cell line, MDA treatment induced vascular endothelial growth factor (VEGF) expression alternation, cell junction disruption, and autophagy dysfunction that was also observed in eyes of AMD patients. The MDA-induced VEGF increase was inhibited by autophagy-lysosomal inhibitors. Intravitreal MDA injection in mice increased laser-induced choroidal neovascularization (laser-CNV) volumes. In a mouse model fed a high-linoleic acid diet for 3 months, we found a significant increase in MDA levels, autophagic activity, and laser-CNV volumes. Our study revealed an important role of MDA, which acts not only as a marker but also as a causative factor of AMD pathogenesis-related autophagy dysfunction. Furthermore, higher dietary intake of linoleic acid promoted CNV progression in mice with increased MDA levels.

Internal inguinal hernia on the transplant side after kidney transplantation: a case report

The patient was a 52-year-old man who presented with right inguinal swelling and pain. He had undergone kidney transplantation in 2005 and bypass surgery using a vascular prosthesis from the left axillary artery to the bilateral femoral arteries in 2008. The vascular prosthesis had invaded the right inguinal canal ventrally. The transplanted ureter had a hazy appearance on a non-enhanced abdominal CT scan. A Lichtenstein operation was performed under a diagnosis of inguinal hernia. A skin incision with pulling of tissue and subcutaneous fat was devised to avoid exposure of the vascular prosthesis. The inguinal canal and spermatic cord were found to have coalesced. The hernia was diagnosed as a supravesical hernia, class II-1. This case shows that a Lichtenstein operation is a suitable procedure for avoidance of damage to the transplanted ureter in treatment of a transplant-side inguinal hernia in a kidney transplant recipient.

Gene expression profile in the activation of subperitoneal fibroblasts reflects prognosis of patients with colon cancer

Tumors can create a heterogenetic tumor microenvironment. We recently identified the pathologically unique cancer microenvironment formed by peritoneal invasion (CMPI), and revealed that subperitoneal fibroblasts (SPFs) within peritoneal tissue play a crucial role in tumor progression through their interaction with cancer cells. Therefore, the genes in SPFs altered by cancer stimulation may include some biologically important factors associated with patient prognosis. In this study, we aimed to identify new biomarkers using genes specifically upregulated in SPFs by cancer-cell-conditioned medium (CCCM) stimulation (SPFs CCCM response genes; SCR genes) in colon cancer (CC). We constructed two frameworks using SCR gene data: a publicly released microarray dataset, and validation cases with freshly frozen CC samples to identify genes related to short recurrence-free survival (RFS). In the first framework, we selected differentially expressed genes between the high and low SCR gene expression groups. In the second framework, genes significantly related to short RFS were selected by univariate analysis using all SCR genes, and multivariate analysis was performed to select robust genes associated with short RFS. We identified CTGF, CALD1, INHBA and TAGLN in the first framework, and PDLIM5, MAGI1, SPTBN1 and TAGLN in the second framework. Among these seven genes, high expression of three genes (CALD1, TAGLN and SPTBN1) showed a poor prognosis in our validation cases. In a public microarray dataset, SCR gene expression was associated with the expression of ECM component, EMT, and M2-macrophage associated genes, which was concordant with the pathological features of CMPI. Thus, we successfully identified new prognostic factors.

Sensing elasticity from the phase difference of the stepper motor

We have developed a made-to-order surgical support manipulator with a function that senses the mechanical characteristics of internal organs, and which can be customized based on the maximum grasping force of the patient. The purpose of this study is to establish an elasticity-sensing model that uses the phase difference of the stepper motor based on material strength and to apply it to in vitro organs. In this study, we propose a measurement model and develop a prototype that is used in experiments on silicon rubber and in vitro organs in a dog. Young's modulus E and spring constant K are measured by the prototype and a material testing machine. The results of the prototype showed good agreement with those of the material testing machine, and that the proposed model will be a great help in the development of surgical support manipulators.

Circulating bone Gla protein in end-stage renal disease determined by newly developed two-site immunoradiometric assay

As a marker for bone formation, bone Gla protein (BGP) levels in the circulation have been measured in clinical research and management for metabolic bone diseases. We evaluated the clinical availability of a newly developed two-site immunoradiometric assay (IRMA) for human BGP and determined the serum BGP concentrations using this methodology in patients with abnormal calcium metabolism including those with end-stage renal disease undergoing maintenance dialysis. A cross-reactivity test revealed that this assay system specifically recognizes intact molecules (1-49) of BGP and excludes fragments of the molecules (1-19, 12-33, 23-33). Serum BGP levels in dialysis patients were positively correlated with those by conventional radioimmunoassay (RIA) (r = 0.918, p less than 0.00001, n = 37) as well as normal individuals (r = 0.935, p less than 0.0001, n = 16). However, the levels of BGP determined by IRMA were estimated to be significantly lower than those by RIA (23.6 +/- 9.8 vs. 29.6 +/- 9.1 ng/ml, p less than 0.00001). These results suggest that this IRMA system, with a rapid and easy procedure, excludes fragment forms of BGP in the circulation, which are found in uremic sera and probably attributed to increased bone resorption. Further studies are needed to ensure that serum intact BGP levels mainly reflect BGP production in osteoblasts, particularly in end-stage renal disease.

Decreased bone mineral density in diabetic patients on hemodialysis

Renal osteodystrophy in hemodialyzed patients with DM-HD shows different features from that in non-DM,HD. Two studies were done. One was a comparison of BMD in 30 non-DM,HD patients and 30 DM-HD patients. The second was a comparison of possible factors affecting calcium metabolism in the higher and lower BMD groups (n = 20/21) in the DM-HD patients. BMD was measured by dual-energy X-ray absorptiometry (DEXA; Hologic QDR 1,000/W) in the third lumbar vertebra (L3), head, pelvis, and whole body. The BMDs of the DM-HD group were lower in these areas and whole body than that in the non-DM,HD group. A significant difference was found in the head BMD (p less than 0.05). In the second study, factors which may contribute to the differences in BMD were compared in the DM-HD patients divided into higher and lower BMD of the head. The group with higher head BMD had a value 110% of the mean value or more. Clinical and biochemical test results (age, the time since the first dialysis, body weight, the degree of obesity, height, serum calcium, serum phosphate, serum aluminum, serum c-PTH level and the dose of 1 alpha-OH-D3) were compared. The degree of obesity of the patients with higher BMD was significantly larger than that with lower BMD (p less than 0.005).

Parathyroid hormone secretion in diabetes mellitus

To investigate the parathyroid function in diabetes mellitus, we performed an oral phosphate load in 6 diabetic patients and 6 nondiabetic subjects without renal failure (serum creatinine less than 1.5 mg/dl). Each subject received a total of 2.0 g of phosphate daily per os on 5 consecutive days. Blood and urine samples were obtained daily before and 2 h after the administration of phosphate in the morning. All subjects responded with a similar increase in the serum phosphorus concentration and fall in the ionized calcium concentration. Intact parathyroid hormone levels rose by 2.6-fold in the control subjects but by less than 1.5-fold in the diabetic subjects. It was concluded that hyporesponsiveness of the parathyroid hormone to phosphate administration was found in the diabetic patients without renal failure.

Uremic serum contains humoral factor(s) larger than fifty kilodaltons which suppresses endothelin production in cultured endothelial cells

Direct effects of human uremic serum on the production of endothelin-1 in cultured porcine endothelial cells were examined in this study. Uremic serum decreased the level of monomeric endothelin-1 secreted into the culture medium by endothelial cells. This effect occurred at a transcriptional step because uremic serum decreased the endothelin-1 mRNA level in those cells. For the partial characterization of this inhibitory activity, uremic serum was fractionated with a centricut column. Uremic serum contains humoral factor(s) larger than 50 kD which suppress the endothelin-1 mRNA level in cultured endothelial cells.