NEW MARKER CENTRE ESTIMATION ALGORITHM OF HIGH ACCURACY IN MOTION ANALYSIS

The non-contact measurement method of motion means almost no discomfort to the moving person or animal. Furthermore, the use of CCD cameras and stroboscopic lighting makes daylight applications possible. As a result a popular and widely used solution in motion analysis is to place markers to landmark points and to characterise motion on the basis of tracking the markers. The actual position of a marker is determined by estimating its centre. The estimation is based on the covered pixels, if several pixels are covered then sub-pixel resolution and accuracy can be achieved. The paper surveys the most commonly used geometric centroid calculation and shows that this method gives a distorted estimation if the set of covered pixels is asymmetrical. In the case of ideal marker images circle fitting does not give a better result, it can be useful if the marker image is partly occluded. A new marker centre estimation algorithm is introduced. It is optimal in the sense that the expected value of the deviation between the actual and the estimated value of a circular marker image is minimal

Conversion of laparoscopic colorectal resection for cancer: What is the impact on short-term outcomes and survival?

Laparoscopic resection for colon and rectal cancer is associated with quicker return of bowel function, reduced postoperative morbidity rates and shorter length of hospital stay compared to open surgery, with no differences in long-term survival. Conversion to open surgery is reported in up to 30% of patients enrolled in randomized control trials comparing open and laparoscopic colorectal resection for cancer. In this review, reasons for conversion are anatomical-related factors, disease-related-factors and surgeon-related factors. Body mass index, local tumour extension and co-morbidities are independent predictors of conversion. The current evidence has shown that patients with converted resection for colon cancer have similar outcomes compared to patients undergoing a laparoscopic completed or open resection. The few studies that have assessed the outcomes after conversion of laparoscopic rectal resection reported significantly higher rates of complications and longer length of hospital stay in converted patients compared to laparoscopically treated patients. No definitive conclusions can be drawn when converted and open rectal resections are compared. Early and pre-emptive conversion appears to have more favourable outcomes than reactive conversion; however, further large studies are needed to better define the optimal timing of conversion. With regard to long-term oncologic outcome, overall and disease-free survival in the case of conversion in laparoscopic colorectal cancer surgery seems to be worse than those achieved in patients in whom resection was successfully completed by laparoscopy. Although a worse long-term oncologic outcome has been suggested, it remains difficult to draw a proper conclusion due to the heterogeneity of the long-term outcomes as well as the inclusion of both colon and rectal cancer patients in most of the studies. Therefore, we discuss the currently available evidence of the impact of conversion in laparoscopic resection for colon and rectal cancer on both short-term outcomes and long-term survival

Surgical Reintervention After Failed Antireflux Surgery: A Systematic Review of the Literature

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Functional outcomes of surgery for colon cancer:A systematic review and meta-analysis

Introduction: As survival rates of colon cancer increase, knowledge about functional outcomes is becoming ever more important. The primary aim of this systematic review and meta-analysis was to quantify functional outcomes after surgery for colon cancer. Secondly, we aimed to determine the effect of time to follow-up and type of colectomy on postoperative functional outcomes. Materials and methods: A systematic literature search was performed to identify studies reporting bowel function following surgery for colon cancer. Outcome parameters were bowel function scores and/or prevalence of bowel symptoms. Additionally, the effect of time to follow-up and type of resection was analyzed. Results: In total 26 studies were included, describing bowel function between 3 to 178 months following right hemicolectomy (n = 4207), left hemicolectomy/sigmoid colon resection (n = 4211), and subtotal/total colectomy (n = 161). In 16 studies (61.5%) a bowel function score was used. Pooled prevalence for liquid and solid stool incontinence was 24.1% and 6.9%, respectively. The most prevalent constipation-associated symptoms were incomplete evacuation and obstructive, difficult emptying (33.3% and 31.4%, respectively). Major Low Anterior Resection Syndrome was present in 21.1%. No differences between time to follow-up or type of colectomy were found. Conclusion: Bowel function problems following surgery for colon cancer are common, show no improvement over time and do not depend on the type of colectomy. Apart from fecal incontinence, constipation-associated symptoms are also highly prevalent. Therefore, more attention should be paid to all possible aspects of bowel dysfunction following surgery for colon cancer and targeted treatment should commence promptly

Prognostic factors in patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy and radical resection of rectal cancer

Background There are only a few studies on the prognosis of patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy (NCRT) and radical resection of rectal cancer. The aim of the study was to identify prognostic factors with regard to oncological outcome in ypT0 patients after NCRT and radical resection. Methods All ypT0 patients with rectal cancer after NCRT and radical resection between January 2010 and June 2019 were included. Cox univariate and multivariate regression analyses were used to determine the prognostic factors of these patients. Results Seventy-six patients with ypT0 rectal cancer were included. In nine patients (11.8%), lymph node metastasis was identified. Age, gender, elevated carcinoembryonic antigen (CEA) and ypN+ were risk factors associated with a worse 5-year disease-free survival (DFS) rate in univariate analysis (P = 0.08, 0.14, 0.007 and 0.003, respectively). In multivariate analysis, ypN+ and elevated CEA before NCRT were independent risk factors for worse 5-year DFS (P = 0.005 and 0.021, respectively). Elevated CEA before NCRT, post-operative chemotherapy and ypN+ were risk factors associated with worse overall survival in univariate analysis (P = 0.14, 0.002 and 0.17, respectively). However, in multivariate analysis, none of these three factors were independent risk factors for worse overall survival (P = 0.20, 0.34 and 0.06, respectively). Conclusion ypN+ and elevated CEA before NCRT were found to be independent risk factors for an unfavourable DFS in ypT0 patients with complete response of the tumour after neoadjuvant chemoradiotherapy for rectal cancer

Clinical and Radiologic Predictors of Parastomal Hernia Development After End Colostomy

OBJECTIVE. Parastomal hernia (PSH) is a common complication that can occur after end colostomy and may result in considerable morbidity. To select the best candidates for prophylactic measures, knowledge of preoperative PSH predictors is important. This study aimed to determine the value of clinical parameters, preoperative CT-based body metrics, and size of the abdominal wall defect created during end colostomy and measured at postoperative CT for predicting PSH development. MATERIALS AND METHODS. Sixty-five patients who underwent permanent end colostomy with at least 1 year of follow-up were included. On preoperative CT, waist circumference, abdominal wall and psoas muscle indexes, rectus abdominis muscle diameter and diastasis, intra- and extraabdominal fat mass, and presence of other hernias were assessed. On postoperative CT, size of the abdominal wall defect and the presence of PSH were determined. To identify independent predictors of PSH development, univariate analysis with the Kaplan-Meier method and multivariate Cox regression analysis were performed. RESULTS. PSH developed after surgery in 30 patients (46%). Three independent risk factors were identified: chronic obstructive pulmonary disease (COPD) as a comorbidity (hazard ratio [HR], 6.4; 95% CI, 1.9-22.0; p = 0.003), operation time longer than 395 minutes (HR, 3.9; 95% CI, 1.5-10.0; p = 0.005), and maximum aperture diameter of more than 34 mm (HR, 5.2; 95% CI, 2.1-12.7; p <0.001). PSH developed in all nine patients with a maximum abdominal wall defect diameter of more than 50 mm at the ostomy site. CONCLUSION. COPD, longer operation time, and larger abdominal wall defect at the colostomy site can predict PSH development. Intraoperative creation of an abdominal wall ostomy opening that is more than 34 mm in diameter should be avoided

Measurement of distal intramural spread and the optimal distal resection by naked eyes after neoadjuvant radiation for rectal cancers

BACKGROUND: The safe distance between the intraoperative resection line and the visible margin of the distal rectal tumor after preoperative radiotherapy is unclear. We aimed to investigate the furthest tumor intramural spread distance in fresh tissue to determine a safe distal intraoperative resection margin length. METHODS: Twenty rectal cancer specimens were collected after preoperative radiotherapy. Tumor intramural spread distances were defined as the distance between the tumor’s visible and microscopic margins. Visible tumor margins in fresh specimens were identified during the operation and were labeled with 5 - 0 sutures under the naked eye at the distal 5, 6, and 7 o’clock directions of visible margins immediately after removal of the tumor. After fixation with formalin, the sutures were injected with nanocarbon particles. Longitudinal tissues were collected along three labels and stained with hematoxylin and eosin. The spread distance after formalin fixation was measured between the furthest intramural spread of tumor cells and the nanocarbon under a microscope. A positive intramural spread distance indicated that the furthest tumor cell was distal to the nanocarbon, and a negative value indicated that the tumor cell was proximal to the nanocarbon. The tumor intramural spread distance in fresh tissue during the operation was 1.75 times the tumor intramural spread distance after formalin fixation according to the literature. RESULTS: At the distal 5, 6, and 7 o’clock direction, seven (35%), five (25%), and six (30%) patients, respectively, had distal tumor cell intramural spread distance > 0 mm. The mean and 95% confidence interval of tumor cell intramural spread distance in fresh tissue during operation was − 0.3 (95%CI − 4.0 ~ 3.4) mm, − 0.9 (95%CI − 3.4 ~ 1.7) mm, and − 0.4 (95%CI − 3.5 ~ 2.8) mm, respectively. The maximal intraoperative intramural spread distances in fresh tissue were 8.8, 7, and 7 mm, respectively. CONCLUSIONS: The intraoperative distance between the distal resection line and the visible margin of the rectal tumor after radiotherapy should not be less than 1 cm to ensure oncological safety