Validation of a 3D-printed model of cryptoglandular perianal fistulas.

INTRODUCTION: Visualising the course of a complex perianal fistula on imaging can be difficult. It has been postulated that three-dimensional (3D) models of perianal fistulas improve understanding of the perianal pathology, contribute to surgical decision-making and might even improve future outcomes of surgical treatment. The aim of the current study is to investigate the accuracy of 3D-printed models of perianal fistulas compared with magnetic resonance imaging (MRI). METHODS: MRI scans of 15 patients with transsphincteric and intersphincteric fistulas were selected and then assessed by an experienced abdominal and colorectal radiologist. A standardised method of creating a 3D-printed anatomical model of cryptoglandular perianal fistula was developed by a technical medical physicist and a surgeon in training with special interest in 3D printing. Manual segmentation of the fistula and external sphincter was performed by a trained technical medical physicist. The anatomical models were 3D printed in a 1:1 ratio and assessed by two colorectal surgeons. The 3D-printed models were then scanned with a 3D scanner. Volume of the 3D-printed model was compared with manual segmentation. Inter-rater reliability statistics were calculated for consistency between the radiologist who assessed the MRI scans and the surgeons who assessed the 3D-printed models. The assessment of the MRI was considered the 'gold standard'. Agreement between the two surgeons who assessed the 3D printed models was also determined. RESULTS: Consistency between the radiologist and the surgeons was almost perfect for classification (κ = 0.87, κ = 0.87), substantial for complexity (κ = 0.73, κ = 0.74) and location of the internal orifice (κ = 0.73, κ = 0.73) and moderate for the percentage of involved external anal sphincter in transsphincteric fistulas (ICC 0.63, ICC 0.52). Agreement between the two surgeons was substantial for classification (κ = 0.73), complexity (κ = 0.74), location of the internal orifice (κ = 0.75) and percentage of involved external anal sphincter in transsphincteric fistulas (ICC 0.77). CONCLUSIONS: Our 3D-printed anatomical models of perianal fistulas are an accurate reflection of the MRI. Further research is needed to determine the added value of 3D-printed anatomical models in preoperative planning and education.

Safe implementation of robotic right colectomy with intracorporeal anastomosis.

The robotic platform can overcome technical difficulties associated with laparoscopic colon surgery. Transitioning from laparoscopic right colectomy with extracorporeal anastomosis (ECA) to robotic right colectomy with intracorporeal anastomosis (ICA) is associated with a learning phase. This study aimed at determining the length of this learning phase and its associated morbidity. We retrospectively analyzed all laparoscopic right colectomies with ECA (n = 38) and robotic right colectomies with ICA (n = 67) for (pre)malignant lesions performed by a single surgeon between January 2014 and December 2020. CUSUM-plot analysis of total procedure time was used for learning curve determination of robotic colectomies. Non-parametric tests were used for statistical analysis. Compared to laparoscopy, the learning phase robotic right colectomies (n = 35) had longer procedure times (p < 0.001) but no differences in anastomotic leakage rate, length of stay or 30-day morbidity. Conversion rate was reduced from 16 to 3 percent in the robotic group. This study provides evidence that robotic right colectomy with ICA can be safely implemented without increasing morbidity.

The complexity of cryptoglandular fistula-in-ano can be predicted by the distance of the external opening to the anal verge; implications for preoperative imaging?

BACKGROUND: Many surgeons believe that the distance from the external opening to the anal verge (DEOAV) predicts the complexity of a cryptoglandular fistulas-in-ano and, therefore, predicts the need for additional imaging. However, there is no evidence to support this. The primary aim of this study was to determine if DEOAV can predict the complexity of a fistula. Secondary aims were clinical outcome and identification of those patients that might not benefit from preoperative imaging. METHODS: All patients having surgery for cryptoglandular fistula-in-ano between January 2014 and December 2016 were evaluated. Preoperative imaging was used to classify fistulas as simple or complex. The DEAOV was measured preoperatively and was divided into categories ≤ 1 cm, 1-2 cm, or > 2 cm. The relationship between the DEOAV and complexity of the fistula was investigated. Clinical outcome was recorded and a group of patients that might not benefit from preoperative imaging was identified. RESULTS: A total of 103 patients [m:f = 65:38, median age 47 (range 19-79) years] were included. Magnetic resonance imaging identified 39 simple and 64 complex fistulas. The percentage of simple fistula was 88% in fistulas with DEAOV ≤ 1 cm, 48% in DEAOV 1-2 cm and 38% in > 2 cm. There was a significant difference between the complexity of the fistula and the distance to the anal verge (p < 0.001). The overall healing rate was 88%. CONCLUSIONS: The complexity of perianal fistula depends on the DEAOV. We propose that preoperative imaging should be performed in fistulas with external opening > 1 cm from the anal verge.

Implementation of laser ablation of fistula tract (LAFT) for perianal fistulas: do the results warrant continued application of this technique?

BACKGROUND: Laser Ablation of Fistula Tract (LAFT) is a novel technique for the treatment of perianal fistulas. Initial reports have shown moderate-to-good results. The aim of this study was to evaluate this implementation and the effectiveness of this technique. Patients were offered LAFT as a treatment option for their perianal fistulas at the outpatient clinic between November 2016 and April 2018. Inclusion criteria were intersphincteric and transsphincteric fistula of cryptoglandular origin [10]. Exclusion criteria were supra- or extrasphincteric fistula, Crohn's disease, presence of undrained collections or side tracts and malignancy-related fistula. The primary outcome was fistula healing rate, the main secondary outcome incidence of postoperative fecal incontinence. Healing and postoperative FISI were evaluated at our outpatient clinic during follow-up at 6 and 12 weeks. A questionnaire was sent to all patients to evaluate the long-term postoperative FISI and patient satisfaction after 3 months. RESULTS: Between November 2016 and April 2018, 20 patients [m:f = 4:16, median age 45 (27-78) years] underwent LAFT. Median follow-up was 10 months (IQR 7.3 months). A draining seton was placed in 15 (75%) of all patients with a median time of 12 weeks (IQR 14 weeks) prior to LAFT. Five intersphincteric and 13 transsphincteric fistulas were treated. Overall healing rate was 20% (4/20). The median postoperative fecal incontinence severity index (FISI) score was 0 (range 0-38); however, we found a change in continence in 39% of the patients. CONCLUSIONS: LAFT has now been discontinued as a treatment of cryptoglandular perianal fistulas in our centre, because of its disappointing results. Further detailed research seems to be warranted to investigate its exact indication and limitations.

The effect of proctoring on the learning curve of transanal minimally invasive surgery for local excision of rectal neoplasms.

BACKGROUND: The current method of choice for local resection of benign and selected malignant rectal tumors is transanal endoscopic microsurgery. Transanal minimally invasive surgery (TAMIS) yields similar oncological results and better patient reported outcomes when compared to transanal endoscopic micro surgery. However, due to the technical complexity of TAMIS, a significant learning curve has been suggested. Data on the surgical learning curve are limited. The aim of our study was to investigate surgeon specific learning curves for TAMIS procedures for the local excision of selected rectal tumors, and analyze the effects of proctoring on operating time and outcome. METHODS: The current study was prospective of all TAMIS procedures performed by two surgeons from October 2010 to November 2017. Margin positivity, specimen fragmentation, adverse events and operative time were evaluated with a cumulative sum analysis to determine the number of procedures required to reach proficiency. Cumulative sum (CUSUM) analysis was used to determine trends in changes over time. RESULTS: The earliest adopter, surgeon A, performed 103 procedures, was not proctored and developed the standardized institutional program. Surgeon B, performed 26 cases, had the benefit of a proctorship and availability of a standardized program. The CUSUM curve for operative time showed a change after 36 cases for surgeon A and after 10 cases for surgeon B. For margin positivity proficiency was reached after 31 and 6 cases for surgeon A and B, respectively. The complications curve for surgeon A showed a three-phase learning curve with a decrease after the 26th case whereas surgeon B only had one (3.8%) complication in the learning phase with no change point in the CUSUM curve. Comparing pre- and post-proficiency periods there was a decrease in operating time for both surgeon A (84.4 ± 47.3 to 55.9 ± 30.1 min) and surgeon B (90.6 ± 64.to 53 ± 26.5 min; p < 0.001). Overall margin positivity rates decreased non significantly from 21.7 to 4.8% (p = 0.23). Complications were higher in the pre-proficiency period (21.7% vs. 13.0%; p = 0.02). Surgeon A had significantly more postoperative complications in pre-proficiency phase when compared to surgeon B (25% vs. none, p < 0.001), in the post-proficiency phase there was no statistically significant difference between both surgeons (p = 0.08). CONCLUSIONS: Our results suggest that to reach satisfactory results for TAMIS, 18-31 procedures are required. Standardized institutional operative protocols together with proficient proctorship may contribute to a shorter learning curve with fewer cases (6-10) required to reach proficiency.

Is colorectal surgery beyond the age of 80 still feasible with acceptable mortality? An analysis of the predictive value of CR-POSSUM and life expectancy after hospital discharge.

AIM: Increased morbidity and mortality could mitigate the positive effect of surgery in elderly patients undergoing colorectal resections. This retrospective study aims to describe early morbidity and mortality together with long-term survival in octogenarians and nonagenarians undergoing colorectal surgery. Predictors for in-hospital mortality are identified. The predictive value of CR-POSSUM is assessed. METHOD: Data on consecutive patients 80 years old or more undergoing a colorectal resection in our centre from 2004 until 2010 were analysed. RESULTS: Some 286 patients [median age 84 years; interquartile range (IQR) 81.6-86.1; 133 men, 47%] underwent a colorectal resection. Median follow-up was 32 months (IQR 14.5-51.2). Two hundred and fifty-eight patients (90%) were operated on for malignancy. Only 64 patients (22.4%) underwent a laparoscopic procedure. Overall median hospital stay was 12 days (IQR 9.0-20.0) and in-hospital mortality was 9.4%. Seventy-six per cent (n = 170) of patients could return home after discharge. The 1-year survival rate was 78.6% (95% CI 73.8-82.7). Median CR-POSSUM for in-hospital mortality was 12.6% (IQR 11.9-21.0). The concordance probability estimate was 0.668 (95% CI 0.609-0.728), reflecting a moderate predictive capacity of CR-POSSUM. Once patients had been discharged from hospital, life expectancy was similar to that of the Belgian general population. CONCLUSION: Colorectal surgery in octogenarians and nonagenarians resulted in a considerable in-hospital mortality of about 9%. One-year mortality added an additional 12%, which is in concordance with the overall life expectancy at that age.