Robotics in the Management of Obstructive Azoospermia (OA)
OA is defined as the absence of any spermatozoa (or sperm precursors) either in the semen or post-ejaculate urine due to a blockage anywhere along the male reproductive tract.[2,17] OA can account for up to 40% of patients who have azoospermia. Obstruction could be due to vasectomy (most common cause), congenital (congenital absence of vas deferens), infection (epididymitis) or iatrogenic (due to scrotal, inguinal or transurethral surgery, for example, inguinal hernia repair). Male infertility patients with OA have two options when considering treatment: (I) surgical correction or reconstruction of the obstruction, or (II) testicular or epididymal sperm retrieval with the use of assisted reproductive techniques (ART) to achieve a pregnancy. This paper will further describe the surgical reconstructive options for these patients and some novel robotic assisted options that have evolved.
Microsurgical vasectomy reversal is an option if the obstruction is in the vas deferens or epididymis. Success rates for microsurgical vasectomy reversal have been reported as high as 98% if bilateral vasovasostomy is performed. Recently, Chan et al. reported 92% patency rates with microsurgical vasoepididymostomy. These procedures are technically challenging and achieving great outcomes requires extensive clinical microsurgical experience and rigorous microsurgical training.[16,22] Microsurgical procedures demand refined surgical skills including precise hand-eye coordination, fine dexterity and minimal hand tremor.
The skill demands on the microsurgeon and the pursuit of further exploring adjunctive tools in microsurgery initially led to the concept of robotic assisted microsurgery in 2003–2004. Robotic assistance in microsurgery was initially attempted in microsurgical vasectomy reversal procedures in animal models. The initial ex vivo and animal trials demonstrated advantages with robotic assistance such as: elimination of tremor, less operative duration and less sperm granuloma formation at the anastomosis site, with comparable patency rates.[10,11,24] The first human case series in 2004 by Fleming et al. suggested greater ease and precision of suture placement and a shorter learning curve. The feasibility of robotic assisted vasectomy reversal was then further supported by another case report by De Naeyer et al. in 2007.
Santomauro et al. recently showed the feasibility and effectiveness of different robotic assisted vasectomy reversal techniques (the one layer and two layer techniques). They also compared the mean console time for experienced staff surgeons versus urology residents. Although the mean console time was 38 minutes for experienced staff and 54 minutes for residents, this was not statistically significant. This group reported a 93% patency rate (sperm in the ejaculate in twelve out of thirteen patients). This is a very interesting study in that it illustrates a fairly rapid learning curve for residents performing this technique and excellent outcomes comparable to some very experienced microsurgical series.
Our group has also compared robotic assisted microsurgical vasectomy reversal and standard microsurgical vasectomy reversal. Patency rates were higher for the robotic assisted microsurgical vasovasostomy (96%) versus the pure microsurgical vasovasostomy (80%), with a P value of 0.002. These included all reversals done by the same microsurgeon in his practice after completing fellowship training during the study period. Our group also documented significantly reduced operative duration with the robot versus pure microsurgery for both vasovasostomy (97 vs. 120 minutes, P=0.0003) and vasoepididymostomy (120 vs. 150 minutes, P=0.0008).
In robotic assisted microsurgery, the preparation of the anastomosis site and the anastomosis technique for vasectomy reversal is identical to the pure microsurgical technique. The difference compared to pure microsurgery is that the microsurgical anastomosis is performed using robotic micro EndoWrist instruments (Intuitive Surgical Inc., Sunnyvale, CA, USA). We utilize Black Diamond micro forceps in the left and right arms, and a Potts scissor in the fourth robotic instrument arm (Figure 1). These instrument arms are all controlled via finger manipulators in the surgeon console. The robot is docked from the right side of the patient and the patient is placed in the supine position. Our technique consists of a double layer anastomosis with five to seven double arm 10–0 nylon sutures for the inner mucosal lumen anastomosis and seven to nine 9–0 nylon sutures for the vasal muscularis anastomosis. We also place a 3–0 Prolene suture to re-approximate the adventitia and create a tension free anastomosis. Robotic vasoepididymostomy (RAVE) is similarly performed with the longitudinal intussusception technique.[6,21] Two double arm 10–0 nylon sutures are utilized to involute the epididymal tubule lumen into the vasal mucosal lumen. The epididymal tunica is then circumferentially re-approximated to the vasal muscularis layer with five to six 9–0 Nylon sutures.
Robotic set-up and instrumentation for robotic vasectomy reversal.
As of October 2013, we have performed 180 robotic assisted vasectomy reversals. Patients' demographics, surgical and post-surgical outcomes are summarized in Table 1. Patients who have more than one million sperm per ejaculate any time after surgery is defined as patent.
The three-dimensional, high-definition magnified view in the surgeon console with six degrees of rotational and articulation ability of the robotic micro instruments provides excellent hand-eye coordination and dexterity for the microsurgeon. Furthermore, elimination of tremor and a stable, ergonomic platform allows the microsurgeon to perform complex maneuvers in a very comfortable setting. The additional fourth instrument arm also eliminates the need for a skilled microsurgical assistant. Finally, the TilePro software in the surgeon console allows for simultaneous viewing of up to three image inputs (Figure 2). Figure 2 illustrates the typical surgeon's view in a RAVE: there are two additional simultaneous image views: one view from the optical phase contrast microscope as the OR technician is assessing the fluid from the epididymal tubule for sperm and another image from the video telescope operating monitor (VITOM) optical magnification camera system (Karl Storz Inc., Tuttlingen, Germany). Having the capability of simultaneously evaluating the epididymal fluid while operating, improves the operative efficiency of the microsurgeon—the surgeon. The additional optical magnification of the VITOM camera system allows for additional optical magnification for the surgeon (this provides up to 15–20× magnification). This five arm robotic approach with the VITOM camera system also obviates the need for the surgeon to zoom in and zoom out during the procedure since each camera is set to different focal lengths—the 3D digital camera providing a more global view at 10–15× and the VITOM providing a high magnification optical view at 15–20×.
Surgeon's view in the surgeon console during robotic vasoepididymostomy: (I) main image from the 3D high-definition robot camera in the middle top; (II) image on the left lower hand side from the optical phase contrast microscope assessing the epididymal fluid for sperm; and (III) image on the right lower hand side from the video telescope operating monitor (VITOM) optical magnification camera (Karl Storz Inc., Tuttlingen, Germany).
The use of robotic assistance for vasectomy reversal also creates some novel opportunities to take microsurgery to places that were once considered difficult to access, such as the intra-abdominal lower pelvis. Najari et al. recently described robotic assisted laparoscopic mobilization of the intra-abdominal vas deferens to allow for an external inguinal tension free anastomosis with standard microsurgical vasovasostomy in a patient who had vasal obstruction from a hernia repair. Trost et al. have taken this one step further, and have described the first bilateral intra-corporeal robotic microsurgical vasovasostomy in a patient who had bilateral vasal obstruction due to prior bilateral inguinal hernia repairs. This is truly a benefit for these patients, since the vasal reconstruction can now be performed intra-abdominally with very small inguinal incisions to mobilize the external vas deferens and then tunnel these proximal segments into the pelvis for the microsurgical reconstruction intra-corporeal. This technique also allows for a tension free anastomosis since it is usually difficult to mobilize very long intra-abdominal vas segments out to the scrotum, and it is technically easier to bring the testicular vas from the inguinal area into the pelvis.
Robotic assisted vasectomy reversal also provides for a convenient training tool for residents and fellows. Some of the newer robotic platforms allow for dual surgeon consoles to allow an experienced surgeon to operate with a trainee simultaneously.
Transl Androl Urol. 2014;3(1):102-112. © 2014 AME Publishing Company