Which technique to choose in the high-tech era of minimal-access rectal cancer surgery?

A novel Foley catheter made of high-intensity near-infrared fluorescent silicone rubber for image-guided surgery of lower rectal cancer

BACKGROUND

Urethral injury occurs in 1-6 % of male cases during minimally invasive surgery of lower rectal cancer. A Foley catheter emitting near-infrared (NIR) fluorescence of sufficient intensity has been expected to locate the urethra during image-guided surgery. Although it has been difficult to impart NIR fluorescent properties to biocompatible thermosetting polymers, we have recently succeeded in developing a NIR fluorescent compound for silicone rubber and a NIR fluorescent Foley catheter (HICARL). Here, we evaluated its NIR fluorescence properties and visibility performance using porcine anorectal isolation specimens.

METHODS

The HICARL catheter was made of a mixture of solid silicone rubber and a NIR fluorescent compound that emits fluorescence with a wavelength of 820-880 nm, while a conventional transparent Foley catheter was made of solid silicone rubber only. As a standard for comparison of the intensity of NIR fluorescence, a transparent Foley catheter the lumen of which was filled with a mixture of indocyanine green (ICG) and human plasma was used. As a comparison to assess the visibility performance of the HICARL catheter, a transparent Foley catheter into which a commercially available NIR fluorescent polyurethane ureteral catheter (NIRC) was placed was used.

RESULTS

A NIR fluorescence quantitative imaging analysis revealed that the Foley-NIRC catheter and the HICARL catheter emitted 3.42 ± 0.42 and 6.43 ± 0.07 times more fluorescence than the Foley-ICG catheter, respectively. The location of the HICARL catheter placed in the anorectum with a wall thickness of 3.8 ± 0.1 mm was clearly delineated in its entirety by NIR fluorescence, while that of the Foley-NIRC catheter was faintly or only partially visible.

CONCLUSIONS

The HICARL catheter emitting NIR fluorescence of sufficient intensity is a promising and easy-to-use tool for urethral visualization during image-guided surgery of lower rectal cancer.

Can MRI pelvimetry predict the technical difficulty of laparoscopic rectal cancer surgery?

PURPOSE

Selection of an open or minimally invasive approach to total mesorectal excision (TME) is generally based on surgeon preference and an intuitive assessment of patient characteristics but there consensus on criteria to predict surgical difficulty. Pelvimetry has been used to predict the difficult surgical pelvis, typically using only bony landmarks. This study aimed to assess the relationship between pelvic soft tissue measurements on preoperative MRI and surgical difficulty.

METHODS

Preoperative MRIs for patients undergoing laparoscopic rectal resection in the Australasian Laparoscopic Cancer of the Rectum Trial (ALaCaRT) were retrospectively reviewed by two blinded surgeons and pelvimetric variables measured. Pelvimetric variables were analyzed for predictors of successful resection of the rectal cancer, defined by clear circumferential and distal resection margins and completeness of TME.

RESULTS

There was no association between successful surgery and any measurement of distance, area, or ratio. However, the was a strong association between the primary outcome and the estimated total pelvic volume on adjusted logistic regression analysis (OR = 0.99, P = 0.01). For each cubic centimeter increase in the pelvic volume, there was a 1% decrease in the odds of successful laparoscopic rectal cancer surgery. Intuitive prediction of unsuccessful surgery was correct in 43% of cases, and correlation between surgeons was poor (ICC = 0.18).

CONCLUSIONS

A surgeon's intuitive assessment of the difficult pelvis, based on visible MRI assessment, is not a reliable predictor of successful laparoscopic surgery. Further assessment of pelvic volume may provide an objective method of defining the difficult surgical pelvis.

Robotic transanal minimally invasive surgery - technical, oncological and patient outcomes from a single institution

AIM

Robotic transanal minimally invasive surgery (R-TAMIS) is gaining traction around the globe as an alternative to laparoscopic conventional TAMIS for local excision of benign and early malignant rectal lesions. The aim was to analyse patient and oncological outcomes of R-TAMIS for consecutive cases in a single centre.

METHODS

A prospective analysis of consecutive R-TAMIS procedures over a 12-month period was performed. Data were collated from hospital databases and theatre registers.

RESULTS

Eleven patients (six men, five women), mean age 69.81 years (51-92 years), underwent R-TAMIS over 12 months utilizing a da Vinci Xi platform. The mean lesion size was 36 mm (20-60 mm) with a mean distance from the anal verge of 7.5 cm (3-14 cm). Five lesions were posterior in anatomical location, four anterior, one right lateral and one left lateral. All procedures were performed in the lithotomy position using a GelPOINT Path Platform. Mean operative time was 64 min (40-100 min). Complete resection was achieved in 10/11 patients with two patients being upgraded to a diagnosis of adenocarcinoma. Nine patients were diagnosed with dysplastic lesions. Four patients had a false positive diagnosis of an invasive tumour on MRI. Six patients required suturing for full-thickness resections. One patient had a postoperative bleed requiring repeat endoscopy and clipping. One patient (full-thickness resection of T3 tumour) proceeded to a formal resection without difficulty with no residual disease (T0N0, 0/22). One patient with a fully resected T2 tumour is undergoing a surveillance protocol. The mean length of stay was 1 day with two patients having a length of stay of 2 days and one patient of 4 days.

CONCLUSION

R-TAMIS could potentially represent a safe novel approach for local resection of rectal lesions.

Future Directions

Transanal total mesorectal excision (taTME) is a novel technique that has evolved over the years to address the challenges of low rectal cancer surgery by applying the principles and benefits of laparoscopic surgery to more historic transanal techniques. It has been popularized through its use in rectal cancer, but the transanal approach is slowly being expanded to tackle different clinical scenarios including benign conditions such as inflammatory bowel disease and endometriosis. For all of these new indications, it is the desire to access and begin the dissection in native tissue beyond the pathology which makes this approach applicable to other diseases where anatomy can be challenging. Training pathways to safely introduce taTME in a standardized manner are being developed and implemented in a bid to ensure adequate training to all the surgeons using this technique and thus minimize complications and patient morbidity. The future directions of this promising technique include the use of image and optical technological enhancement to aid navigation, the use of pneumorectum stabilization, and perhaps the use of fluorescence as a safety improvement. Developments have come also from the field of robotics. After a demonstration of feasibility in cadaver models, a growing experience has been gathered in the robotic approach to taTME, covered in the last part of this chapter.

Is there still a place for open surgery in the treatment strategy of rectal cancer?

Over the last 30 years laparoscopic surgery of rectal cancer has been progressively gaining popularity due to expanding experience and the development of technical skills according to the surgeons’ learning curves. The report constitutes a review of recently published articles concerning surgical techniques in colon cancer, with special emphasis on rectal cancer treatment. We tried to address the question of whether, in view of further development and broader use of laparoscopic surgery, there still is a place for open surgery in the treatment strategy of rectal cancer.

Robotic transanal minimally invasive surgery (TAMIS) for local excision of rectal lesions with the da Vinci Xi (dVXi): technical considerations and video vignette

Robotic transanal minimally invasive surgery (TAMIS) (RT) represents a compelling new alternative capable of overcoming the limitations of conventional TAMIS for the local excision of rectal lesions. We describe our RT technique using the dVXi™ (Intuitive Surgical, Sunnyvale, CA, USA) which we have used to efficiently and completely excise eight cases of rectal lesions which were not endoscopically resectable. We also include a video vignette of the procedure. With the patient in the prone jackknife position, we insert a GelPOINT™ Path Transanal Access Platform (Applied Medical, Rancho Santa Margarita, CA, USA) in combination with the dVXi and AirSeal™ insufflation system (Conmed, Niagara. Falls, ON, Canada). Our technique aims to be ergonomically efficient to minimise docking difficulties and to reduce instrument clash in the limited space, whilst maximising the capabilities of the dVXi for RT. At 3-month endoscopic follow-up, no evidence of recurrence was detected in any of the eight patients. RT is safe, feasible and has advantages over conventional laparoscopic TAMIS (LT). Our described technique addresses some of the long-standing challenges of LT and the novel RT. The immediate challenge to its widespread use remains the cost, expertise and availability.

Conventional and/or laparoscopic rectal cancer surgery: what is the current evidence?

Despite many years of experience with laparoscopic procedures in rectal cancer, the superiority of minimally invasive approaches has been questioned especially in recent years. This article is a short review of the current knowledge about laparoscopic approaches in comparison to conventional modalities in patients with rectal cancer. To present the current state of the knowledge, we focused on reports that were published in the last few years and compared them to multicenter trials and meta-analyses published last year. Our analysis mainly applied to the primary end-points of these trials. We also included expert opinions that have been published in the last several months.