Background
Automatic surgical workflow recognition is a key component for developing the context-aware computer-assisted surgery (CA-CAS) systems. However, automatic surgical phase recognition ...focused on colorectal surgery has not been reported. We aimed to develop a deep learning model for automatic surgical phase recognition based on laparoscopic sigmoidectomy (Lap-S) videos, which could be used for real-time phase recognition, and to clarify the accuracies of the automatic surgical phase and action recognitions using visual information.
Methods
The dataset used contained 71 cases of Lap-S. The video data were divided into frame units every 1/30 s as static images. Every Lap-S video was manually divided into 11 surgical phases (Phases 0–10) and manually annotated for each surgical action on every frame. The model was generated based on the training data. Validation of the model was performed on a set of unseen test data. Convolutional neural network (CNN)-based deep learning was also used.
Results
The average surgical time was 175 min (± 43 min SD), with the individual surgical phases also showing high variations in the duration between cases. Each surgery started in the first phase (Phase 0) and ended in the last phase (Phase 10), and phase transitions occurred 14 (± 2 SD) times per procedure on an average. The accuracy of the automatic surgical phase recognition was 91.9% and those for the automatic surgical action recognition of extracorporeal action and irrigation were 89.4% and 82.5%, respectively. Moreover, this system could perform real-time automatic surgical phase recognition at 32 fps.
Conclusions
The CNN-based deep learning approach enabled the recognition of surgical phases and actions in 71 Lap-S cases based on manually annotated data. This system could perform automatic surgical phase recognition and automatic target surgical action recognition with high accuracy. Moreover, this study showed the feasibility of real-time automatic surgical phase recognition with high frame rate.
CD44 and CD133 are stem cell markers in colorectal cancer (CRC). CD44 has distinctive isoforms with different oncological properties like total CD44 (CD44T) and variant CD44 (CD44V). Clinical ...significance of such markers remains elusive.
Sixty colon cancer were examined for CD44T/CD44V and CD133 at mRNA level in a quantitative PCR, and clarified for their association with clinicopathological factors.
(1) Both CD44T and CD44V showed higher expression in primary colon tumors than in non-cancerous mucosas (p<0.0001), while CD133 was expressed even in non-cancerous mucosa and rather decreased in the tumors (p = 0.048). (2) CD44V expression was significantly associated with CD44T expression (R = 0.62, p<0.0001), while they were not correlated to CD133 at all in the primary tumors. (3) CD44V/CD44T expressions were significantly higher in right colon cancer than in left colon cancer (p = 0.035/p = 0.012, respectively), while CD133 expression were not (p = 0.20). (4) In primary tumors, unexpectedly, CD44V/CD44T/CD133 mRNA expressions were not correlated with aggressive phenotypes, but CD44V/CD44T rather significantly with less aggressive lymph node metastasis/distant metastasis (p = 0.040/p = 0.039, respectively). Moreover, both CD44V and CD133 expressions were significantly decreased in liver metastasis as compared to primary tumors (p = 0.0005 and p = 0.0006, respectively).
Our transcript expression analysis of cancer stem cell markers did not conclude that their expression could represent aggressive phenotypes of primary and metastatic tumors, and rather represented less demand on stem cell marker-positive cancer cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose
For locally advanced pathological T4 (pT4) colon cancer, the safety and feasibility of laparoscopic procedures remain controversial. Therefore, this study aimed to assess short-term and ...long-term outcomes and to identify the prognostic factors in laparoscopic surgery for pT4 colon cancer.
Methods
The study group included 130 patients who underwent laparoscopic radical resection for pT4 colon and rectosigmoid cancer from January 2004 through December 2012. The short-term outcomes, long-term outcomes, and prognostic factors in pT4 colon cancer were analyzed.
Results
The median operative time was 205 min, with a median blood loss of 10 ml. The conversion rate was 3.8%, and 13 patients (10.0%) had postoperative complications. The radial resection margin was positive in 1 patient (0.8%). The median follow-up time was 73 months. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 77.2 and 63.5%, respectively. On a multivariate analysis, a male sex hazard ratio (HR) 3.09,
p
< 0.001, lymph node ratio ≥ 0.06 (HR 2.35,
p
= 0.021), tumor diameter < 38 mm (HR 2.57,
p
= 0.007), and right-sided colon cancer (HR 2.11,
p
= 0.047) were significantly related to a poor OS.
Conclusions
These results suggest that laparoscopic surgery for pT4 colon cancer is safe and feasible, and the oncological outcomes are acceptable. Based on the present findings, select patients with locally advanced colon cancer should not be excluded from laparoscopic surgery.
Introduction
The advantages of robotic‐assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short‐term outcomes of RALS for rectal cancer ...with those of conventional laparoscopic surgery (CLS).
Methods
The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score‐matched analysis. After matching, 188 patients were enrolled in our study to compare short‐term outcomes, such as operative results, postoperative complications, and pathological findings, in each group.
Results
After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested.
Conclusion
Robotic‐assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short‐term outcomes. Further studies are required to validate long‐term oncological outcomes.
Background
Myopenia and myosteatosis are reported to be long‐term prognostic factors in patients with colorectal cancer (CRC). However, the established parameters are unsuitable for the Japanese ...population because their body composition is different from that of the Western population.
Objective
We aimed to elucidate the effect of skeletal muscle changes among Japanese adults, measured using preoperative computed tomography (CT) as a prognostic factor in patients with stage III CRC.
Patients
We retrospectively analyzed 341 patients diagnosed with stage III CRC. The cross‐sectional area (skeletal muscle index: SMI) and mean radiodensity of skeletal muscle (skeletal muscle radiodensity: SMR) were measured using preoperative CT. The optimal sex‐specific cutoff value, which was used to divide the patients according to the risk of recurrence, was set for SMI and SMR. Univariate and multivariate analysis were performed to determine the prognostic factors for recurrence‐free survival (RFS).
Results
The cutoff values of SMI for men and women were set as 48.5 and 41.4, respectively, and those of SMR were 35.0 and 21.7, respectively. Univariate analysis identified low SMI and SMR in men and low SMR in women as the worst prognostic factors for RFS. Multivariate analysis identified low SMI in men and low SMR in women as independent poor prognostic factors for RFS (hazard ratio HR = 1.87, 95% confidence interval CI, 1.08–3.47, P = .03 and HR = 2.49, CI, 1.21–4.95, P = .01).
Conclusion
Low SMI in men and low SMR in women were the independent prognostic factors for patients with stage III CRC.
Low SMI in men and low SMR in women were the independent worse prognostic factors in stage III colorectal cancer.
Purpose
To clarify the risk factors for complications after diverting ileostomy closure in patients who have undergone rectal cancer surgery.
Methods
The study group comprised 240 patients who ...underwent a diverting ileostomy at the time of lower anterior resection or internal anal sphincter resection, in our department, between 2004 and 2015. Univariate and multivariate analyses of 18 variables were performed to establish which of these are risk factors for postoperative complications.
Results
The most common complications were intestinal obstruction and wound infection. Univariate analysis showed that an age of 72 years or older (
p
= 0.0028), an interval between surgery and closure of 6 months or longer (
p
= 0.0049), and an operation time of 145 min or longer (
p
= 0.0293) were significant risk factors for postoperative complications. Multivariate analysis showed that age (odds ratio, 3.4236;
p
= 0.0025), the interval between surgery and closure (odds ratio, 3.4780;
p
= 0.0039), and operation time (odds 2.5179;
p
= 0.0260) were independent risk factors.
Conclusions
Age, interval between surgery and closure, and operation time were independent risk factors for postoperative complications after diverting ileostomy closure. Thus, temporary ileostomy closure should be performed within 6 months after surgery for rectal cancer.
Introduction
Clinical use of an adhesion barrier made of oxidized, regenerated cellulose, Interceed®, has been reported in the field of obstetrics and gynecology to help prevent adhesions between the ...peritoneum and the bowel in various types of operations. In gastrointestinal surgery, sodium hyaluronate/carboxymethylcellulose has been reported as an absorbable membrane to reduce postoperative adhesions. The present study was a prospective randomized controlled study to investigate the safety and usefulness of Interceed in laparoscopic colorectal surgery.
Methods
We analyzed 99 patients who underwent laparoscopic colorectal surgery from 2013 to 2014. The patients were randomly allocated to the group that used Interceed (Interceed group) or the group that did not (Non‐Interceed group).
Results
Fifty cases used Interceed, and 49 cases did not. The incidence of adverse events was 12.0% in the Interceed group and 16.3% in the Non‐Interceed group (P = 0.58). There were no significant differences, and no adhesive bowel obstructions were observed in the Interceed group.
Conclusion
We have shown that using Interceed in laparoscopic colorectal surgery is valid and technically safe.
The benefits of robot-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. Only a few studies have evaluated the safety and feasibility of RALS following neoadjuvant ...chemoradiotherapy (NCRT). This study aimed to compare the short-term outcomes of RALS versus conventional laparoscopic surgery (CLS) after NCRT for rectal cancer. Propensity score matching of 111 consecutive patients who underwent RALS or CLS after NCRT for rectal adenocarcinoma between February 2014 and February 2022 was performed. Among them, 60 matched patients were enrolled and their short-term outcomes were compared. Although operative time, conversion rate to open laparotomy and blood loss were comparable, the incidence of postoperative complications, including anastomotic leakage, was significantly lower, urinary retention tended to be lower, and the days to soft diet intake and postoperative hospital stay were significantly shorter in the RALS than the CLS group. No postoperative mortality was observed in either group, and there were no significant differences in terms of resection margins and number of lymph nodes dissected. RALS after NCRT for rectal cancer is safe and technically feasible, and has acceptable short-term outcomes. Further studies are required for validation of the long-term oncological outcomes.
This paper describes the applicability of a method, proposed by Noto (1991a), to the prediction of the settlement of a peaty ground from an engineering viewpoint. The settlement of peaty grounds ...cannot be fully explained by Terzaghi׳s theory. Noto proposed a method for predicting the settlement behavior in peaty grounds on the basis of the statistical analyses of numerous oedometer test results. For the purpose of verifying the applicability of the Noto method, data on the settlement of full-scale test embankments, built in Hokkaido, Japan, were compared with predictions obtained by this method. The comparison quantitatively revealed the primary consolidation rate and the coefficient of secondary consolidation of the peaty ground as well as the prediction accuracy of the Noto method.
Berm drainage ditches may fail due to frost heave in cold and snowy areas like Hokkaido. Many of these failures are regarded to be caused by damage due to frost heave in the ground or freeze-thaw, ...but no sufficient measures are being taken, as construction guidelines and procedures do not describe any established countermeasures for the damage. Therefore, it was decided to study countermeasures by utilizing berm drainage ditches that can change form in response to frost heave, rather than by trying to reduce the level of change caused by frost heave. A drainage ditch made of flexible asphalt sheets was constructed on site, and the soil temperature, frost penetration depth, frost heave amount, and other parameters were measured. As a result, it was found that a drainage ditch made of asphalt sheets is more effective when ground conditions including moisture and temperature are severe in relation to frost heave.
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