Technique  and outcomes

Both robotic and pure microsurgical approaches are per- formed with the same surgical principles [12,18]. The two ends of the vas deferens are prepared through a scrotal incision and the proximal (testicular) vas fluid is assessed to see if any sperm are present. RAVV is performed if sperm are found in the proximal vas deferens. If no sperm are found in the proximal vas deferens, a RAVE is then performed. The da Vinci robotic platform is docked on the  right  side  with the  patient supine.  Black  diamond micro-forceps are used as needle drivers in the left and right arms, and the Potts scissors in the fourth arm are used to cut tied sutures (Fig. 2). This configuration allows the surgeon to control three instruments, thus obviating the need for a skilled microsurgical assistant.

Suture materials and surgical techniques are  similar to those used in standard microsurgery. Eight to 10 9- 0 nylon sutures are used for the muscularis anastomosis. Five to six double-arm 10-0 nylon sutures are used for mucosal lumen anastomosis (Fig. 3). The two posterior 9-0 sutures are first placed to anastomose the posterior muscularis plate. Two 10-0 posterior sutures are then used to anastomose the posterior mucosal plate. Four to five 10-0 anterior sutures are placed to complete the mucosal lumen anastomosis. Six to eight 9-0 nylon sutures are used to complete the anterior muscularis anastomosis.

In RAVE, two double-arm 10-0 sutures are used for vasal mucosal lumen to epididymal tubule anastomosis (Fig. 4) using a longitudinal intussusception technique. The vasal muscularis layer is sutured to the epididymal tunica using six to eight 9-0 nylon   sutures.

The 0° camera of the da Vinci robotic platform    pro-vides up to × 12–15 magnification. This five-arm robotic approach enables microsurgeons to perform challenging manoeuvres,  including  ultrafine  suture  placement  and knot tying at two different focal lengths (two different View from surgeon console during RAVV. Main view from the camera system of the da Vinci robotic platform in the middle, the real-time image from the right side with the andrology optical microscope (×100), and the view from the left side with the VITOM® (Karl

Storz GmbH & Co. KG, Tuttlingen, Germany) camera view for enhanced magnification.

camera views, each at a different magnification), without needing to zoom in and out. The simultaneous viewing capabilities also allow microsurgeons to evaluate semi- nal fluid or tissues without having to stop    operating.

Robot-assisted microsurgery also allows for novel microsurgical approaches; it allows  microsurgery to be performed in locations of the body that would otherwise be difficult to access with open and standard microscopic techniques. Trost et al. [18] described the first bilateral intracorporeal RAVV in a patient who had bilateral iatrogenic vasal obstruction from prior bilateral inguinal hernia repair. They reported a suc- cessful minimally invasive bilateral intracorporeal anas- tomosis. This procedure requires a very large abdominal incision with standard microsurgical and open approaches but with the  robotic  approach  it can be performed with only four small skin incisions (port sites, <1 cm each). Barazani et al. [19] reported the first case of intra-abdominal RAVV used to repair obstructive azoospermia resulting from prior laparo- scopic vasectomy.

Our group reported outcomes for 180 vasectomy reversal procedures (106 RAVV, 74 RAVE), with 97% and 55% success rates in the RAVV and RAVE proce- dures, respectively. The median  operative durations (skin to skin) were also reasonable, at 120 min for RAVV and 150 min for RAVE [20].

Robotics in the management of   varicocele

The presence of a varicocele leads to a two-fold increase in the likelihood of having abnormal semen analysis parameters in men seeking infertility treatment [21]. Varicocelectomy can lead  to  significant improvements in semen analysis parameters and a meta-analysis showed significant improvements in sperm count and motility regardless of the varicocelectomy technique [22].