Laser Welded Vesicourethral Anastomosis in an In Vivo Canine Model: A Pilot Study

All you need to know about urethrovesical anastomotic urinary leakage following radical prostatectomy

PURPOSE

Radical prostatectomy is a challenging operation demanding a high level of surgical expertise and experience. Urinary leakage at the urethrovesical anastomosis is one of the most common short-term complications of radical prostatectomy, reaching an incidence of 0.3% to 15.4%. In this review we investigate and discuss all matters directly related to urethrovesical anastomotic leak, specifically how to diagnose it properly, how to determine when it is clinically significant and when intervention is required, how to prevent or predict it and, finally, the possible long-term sequelae.

MATERIALS AND METHODS

We conducted a systematic analysis of the literature searching for English and nonEnglish language publications from a preidentified time frame (1985 to 2011) using primary search databases (PubMed®, Web of Science®). Manual selection was performed by 2 authors and the third reviewed the final common selection. We also created an algorithm for the diagnosis and management of urethrovesical anastomotic leak.

RESULTS

A total of 72 studies were finally selected, including 48 (67%) observational case series, 16 (22.2%) prospective trials, 1 letter to the editor, 1 review and 1 systematic review which was focused only on laparoscopic radical prostatectomy. We also found 2 experimental studies performed in animal models and 3 case reports. Of these studies 7 reported results from fewer than 20 patients. No consensus was recorded on a strict definition of urethrovesical anastomotic leak. The factors determining possible definitions included postoperative day of urethrovesical anastomotic leak, amount of extravasation on cystography and the need for intervention. Urethrovesical anastomotic leak should be classified according to the Clavien classification system, depending on severity and the need for intervention. To our knowledge the role of the open, laparoscopic or robotic approach in the incidence of urethrovesical anastomotic leak has not been systematically investigated. Risk factors for urethrovesical anastomotic leak include obesity, prostate size, previous prostatic surgery, type of anastomosis technique, suture number and type, eversion of the mucosa, a difficult anastomosis or an anastomosis under tension, reconstruction of the musculofascial plate, blood loss, intraoperative flush test result and postoperative urinary tract infection. Diagnosis can be determined primarily by establishing the nature of the drain output. Retrograde cystography, computerized tomography cystography, transrectal ultrasound, contrast enhanced ultrasound and excretory urography are the indicated imaging modalities, and are not always necessary. Finally, the development of anastomotic stricture and incontinence due to urethrovesical anastomotic leak are additional complications.

CONCLUSIONS

We gathered all relevant critical information concerning urethrovesical anastomotic leak to encourage standardization in the diagnosis and management of this common complication. Systematic meta-analysis of each debatable issue is required to provide definite answers.

[Lasers in urology]

The objective of this article is to quote under the form of a document the opinions expressed by the participants of the round table "Lasers in Urology Today" (january 2006). The material and method used is the compilation of critical and updated notions on the usefulness of lasers in urology, supplemented by bibliographic references, a limited iconography. The results achieved by lasers today enable us to state that: Holmium laser is the choice treatment for in situ lithotripsy; however, it has not significantly improved previous results when treating urologic tumours and stenoses. Nowadays we have two types of lasers: KTP and HoL, which obtain results similar to surgery regarding BPH, but with reduced morbidity. The usefulness of laser in laparoscopic surgery is still under development.

CONCLUSION

Lasers in Urology Today play an active role in in situ lithotripsy (HoL), and a competitive one in BPH surgery (KTP and HoL). Regarding the rest of indications, i.e. tumours, stenoses, laparoscopic surgery, etc., further studies and enough follow-up times are still needed.

Methods for laparoscopic training using animal models

To reduce the learning curves in humans, several training models have been developed for teaching laparoscopic surgery. The aim of various in vitro or in vivo training models is to help surgeons acquire basic laparoscopic skills such as hand-eye coordination, depth perception, and knot-tying, which should always be acquired prior to organ- or procedure-specific skills. Inexpensive video box trainers are best suited for this purpose. However, advanced laparoscopic skills, such as dissection, cutting, coagulation, and stitching, require more sophisticated animal or human cadaver models. The perfect training model should teach the skills required and should be inexpensive, universally available, and anatomically and physiologically identical to an anesthetized patient. In this paper, we review the different animal models for acquiring advanced laparoscopic skills and try to define their advantages and disadvantages.

Laparoscopic radical prostatectomy: review and assessment of an emerging technique

BACKGROUND

Several recent reports have affirmed the feasibility of the laparoscopic approach for radical prostatectomy. In this review, we discuss the morbidities associated with this technique and compare outcomes and convalescence with standard open radical prostatectomy.

METHODS

We reviewed all currently published data on laparoscopic radical prostatectomy and our series of 45 robotic-assisted radical prostatectomies and compared them to several landmark series of open retropubic and perineal radical prostatectomies.

RESULTS

Although the initial series reported long operating times, these times have been significantly reduced in more recent series. Data on blood loss, convalescence, impotence, and incontinence rates have also been promising.

CONCLUSIONS

Although follow-up has been short thus far, laparoscopic radical prostatectomy has been shown to be similar to open radical prostatectomy in several areas.

Intraluminal laser light source and external solder: In vivo evaluation of a new technique for microvascular anastomosis

BACKGROUND AND OBJECTIVES

Current laser-assisted end-to-end anastomoses are performed by irradiating the vessel wall from outside after additional fixation with three to six sutures. These sutures are needed to provide adequate approximation of the vessel stumps. We present a new laser soldering technique that is based on an intraluminal laser light source centered in a balloon catheter, and external application of a solder. This technique was applied in vivo in order to test its feasibility under clinical conditions.

STUDY DESIGN/MATERIALS AND METHODS

Seven white pigs were treated with a total of fourteen end-to-end laser-anastomoses of their saphenous arteries having outer diameters of 2 mm. The vessels were stented over an intraluminal balloon catheter, which was maximally dilated and which allowed for a precise approximation of the vascular stumps. An 808 nm diode laser was coupled into a specially designed optical fiber producing a 360 degrees radiation ring inside the balloon catheter. An indocyanine green (ICG) doped liquid albumin solder was applied on the external surface of the vascular stumps. Laser soldering was achieved by irradiating with a 808 nm laser diode for 75 seconds. Tightness of the anastomoses was evaluated by clamping the artery distal to the anastomosis for 1 hour, and patency was tested over an observation period of 3 hours, during which the animals were heparinized. Thereafter, the anastomoses were harvested for histomorphological examination.

RESULTS

All anastomoses remained patent over the entire observation period. Some leakage was observed in three anastomoses, which was explained by a deviation of the illumination fiber from the center of the balloon leading to an inhomogeneous irradiation of the vessel wall. Histology revealed perfect adaptation of the vascular stumps. A segment of denaturated vascular collagen was observed, that corresponded to the irradiated, solder-covered zone.

CONCLUSION

Patent, maximally dilated and well adapted microvascular anastomoses could be obtained without the need of stay sutures. A well centered laser light source is indispensable for avoiding inhomogenous welding, thus causing leakage.

Laser tissue soldering: applications in the genitourinary system

Within the past 25 years, lasers have transitioned from merely destructive or ablative tools to those with reconstructive uses. It has been shown that the application of laser thermal energy to tissue will result in welding of the approximated areas. Furthermore, the addition of protein solder and chromophores (tissue soldering) has increased wound tensile strength while decreasing peripheral tissue damage. Laboratory studies have demonstrated application of laser tissue soldering to virtually all components of the genitourinary system. Increasing human experience in recent years has reinforced the success of this technique.