The quest for the application of laparoscopy to radical prostatectomy started in 1992, when Schuessler et al. first pioneered such intervention: the procedure however was associated with long operative times and did not show major significant clinical advantages compared to the open approach [37]. Several years after, in 2000, Guillonneau et al. and Abbou et al. reported their stepwise techniques with operative times between 4 and 5 h, in addition to reasonable oncologic and functional results [1, 14].

As such, laparoscopic prostatectomy began to be performed in different excellence centers across Europe and USA; nonetheless the procedure was and is complex, and, especially in the years prior to the vast distribution of the DaVinci robotic system, the learning curve was steep, requiring approximately 50 procedures to be mastered [8, 43]. Specifically, the vesico-urethral anastomosis has always been a crucial, time consuming step of major difficulty [8, 12, 37].

In the beginning, interrupted sutures had been proposed by the first pioneers of this intervention [14, 31]. Guillonneau and Vallencien proposed throwing two posterior stitches at 5 and 7 o’clock, then 6 stitches at 1, 2, 4, 8, 10 and 11 o’clock. With a total of seven separate knots, these techniques were incredibly complicated and long, and therefore running suture methods began to be explored. Hoznek et al. in 2000 reported their method of performing a running VUA: two hemi-circumferential sutures, one anterior and one posterior, are thrown respectively from 3 to 9 o’clock (posterior), and from 2 to 10 o’clock (anterior). This technique necessitates four intracorporeal knots, and in its first report required on average 31 min to be completed [20]. Gaston and Piechaud popularized the “Bordeaux technique”, a single running suture which starts at the 3 o’clock position and continues in a clockwise direction [6]; this method has been modified by Pansadoro et al. to reduce the number of intracorporeal knots to only one and facilitate the throw of the posterior stitches [11]. However, notwithstanding the multiple attempts to simplify the technique, the VUA was and is today still terribly challenging, especially for novice laparoscopic surgeons. The reasons are numerous: first, laparoscopic intra-corporeal suturing and knot-tying is one of the most complicated technical gestures that a surgeon must learn during his training. Albeit training programs and simulators, indeed many young surgeons struggle when it gets to intra-corporeal knot tying, notably in the vesico-urethral anastomosis were forehand and backhand stitches must be placed. Second, the anatomic position of the urethra makes the vesico-urethral anastomosis a naturally complicated procedure: especially in men with a narrow and/or deep pelvis, placing the urethral stitches may be incredibly challenging. Finally, laparoscopic radical prostatectomy, especially in the beginning of a surgeon’s learning curve, is a long and wearing procedure. Therefore, surgeons find themselves to face a complex step in the procedure (i.e., the VUA) after several hours of concentration and difficult dissection, boosting the VUA’s complexity.

In 2000 in our center we introduced a single-knot running VUA, today more known as the Van Velthoven technique. Its initial series was published in 2003 [44]. This technique requires only one intracorporeal knot, it allows a water-tight approximation of the bladder neck to the urethra and is easily teachable. As such, although many variations have been proposed and are currently in use in centers worldwide [22, 25, 39], this technique has been widely accepted by many urologists and is frequently used today to perform VUA [26].

The basic principle of a good vesico-urethral anastomosis is to obtain without tension and/or traction a precise alignment of the urethra with the preserved or reconstructed bladder neck. The key point is to obtain a non-ischemic, watertight anastomosis that prevents urinary leakage without compromising the integrity of the external sphincter. The method should be cost effective, easy to learn and perform and should not be time consuming. The quality of the vesico-urethral anastomosis is responsible for preventing urinary leakage and stricture formation, and consequently for preserving continence. The success of a vesico-urethral anastomosis therefore depends upon meticulous attention to detail and the optimization of technical factors that affect anastomotic integrity. The single-knot running vesico-urethral anastomosis respects this principle and has become a commonly used method of reconstruction [44].

The technique begins by inspecting the bladder neck with careful attention to ureteral orifices. The degree of bladder neck preservation will dictate the length of the suture. It varies accordingly between 12 and 20 cm. The running suture is prepared extracorporally by tying together the two ends of a twin dyed 6 in. sutures of 3-0 Monocryl RB-1 (Ethicon, USA). The second step is to identify the urethral stump. Sometimes the urethral stump is too short and retracts into the pelvic floor musculature, or is positioned deep underneath the symphysis pubis, so that visualizing and placing the anastomotic sutures in laparoscopy could be difficult. A simple trick to facilitate suturing is to exert an external perineal pressure with a sponge stick at the bulbar urethra during the initial throws of the suture, thus everting the urethral stump. The running stitch is initiated by placing both needles outside-in through the bladder neck and inside-out on the urethra, one needle at the 5:30-o’clock position and the other needle at the 6:30-o’clock position. The sutures are run from the 6:30 and 5:30-o’clock positions toward the 9:00 and 3:00-o’clock positions, respectively. After two throws through the urethra and three throws through the bladder are completed, the sutures are cinched down with gentle traction on each thread simultaneously or alternately, bringing the bladder neck as a unit tightly into position with the urethra. This approximation provides a secure posterior wall with no gap visualized between sutures and allows a 20F catheter to be placed into the bladder. A transition suture is completed at the 11:00 -o’clock positions, by taking an extra bite on the urethra, going outside in. The transition suture allows the stitch to now exit the bladder on its outer surface. The sutures are continued to the 12:00-o’clock position and tied to each other. This solitary intracorporeal knot now, like the initial extracorporeal knot, rests on the exterior of the bladder. If discrepancy persists between the diameters of the bladder neck and urethra, an anterior tennis racket-type closure is performed. If the ureteral orifices are close, a posterior tennis racket-type closure is advised. The balloon on the 20F catheter is filled with 10 mL of water; the bladder is irrigated until clear with approximately 60 mL of sterile water. A drain is placed and is usually removed on the first postoperative day. The catheter is normally left in place for 5 days and is removed after documenting on a cystogram a watertight anastomosis.

In analysis of three different vesico-urethral anastomotic techniques in laparoscopic radical prostatectomy by Teber et al. [41], the single knot running anastomosis was associated with a significantly decreased anastomotic and overall operative time compared to interrupted and modified interrupted technique. The median time to perform a single knot running anastomosis laparoscopically was 15.3 min (range 11–31) in their series. The reduction in requirement for knot-tying may enable surgeons with limited suturing experience to master this difficult technical step, unavoidably located at the end of a challenging procedure. Furthermore, the system of symmetric loops act as a block and pulley mechanism, thereby enabling approximation of the dorsal part of the anastomosis to be carried out without tension or traction. In addition, it is not possible to perform an interrupted anastomosis without using two needle drivers and at least 6 suture materials. The single-knot running technique proves that even with a single needle driver, a running stitch with two suture materials is still possible. Of note, the cost of two Monocryl 3-0 RB-1 suture materials per procedure is approximately 7€ and the cost saved per procedure by using only one robotic needle driver in RALP is around 220€. The savings achieved by this technique associated to a decrease in overall operative time reduce the global cost of an economically consuming operation.

As any surgical step in radical prostatectomy, the VUA is characterized by possible complications. The surgeon must master the technique of VUA to reduce these events, which however remain inevitable, as normal in surgery.

An anastomotic leak is short term complication following vesico-urethral anastomosis and is associated with significant morbidity including postoperative ileus, infection, metabolic abnormalities, and prolonged hospital stay and urinoma formation with potential risk of anastomotic disruption. The long term relevance of an anastomotic leak is controversial in the literature. Surya et al. suggested that prolonged urine leaks are a risk factor for anastomotic stricture [40]. They suggest that prolonged urinary leakage results from an anastomotic gap which heals by second intention, thereby causing scarring and anastomotic stricture. By contrast, other studies have reported no significant increase in anastomotic stricture due to leakage [36, 41, 48].

However, the presence of pelvic drains removing extravasated urine may have biased these studies towards finding no effect of postoperative anastomotic urine leak on long term morbidity. The reported incidence of anastomotic leak with single knot running sutures has been very variable ranging from 0 to 7.5 % [16, 33] in series of surgeons using the single-knot running technique. In a study by Cohen et al. urine leak was significantly reduced in the group of single knot running sutures compared to the interrupted technique [7]. Teber et al. also demonstrated significantly less dorsal urine leak with the Van Velthoven technique than with interrupted sutures [41].

Anastomotic strictures are a late, Clavien grade III complication of radical prostatectomy. Most surgical series in which the single-knot method was used to perform VUA report stricture rates ranging from 0 to 3 % [16, 19, 23, 33, 41]. Significant morbidity may be associated with the development of an anastomotic stricture, including infection, urinary retention, the need for additional invasive surgery and future incontinence [13]. While several factors have been associated with the development of anastomotic stricture, its exact pathophysiology remains poorly defined. Both technical and patient-related factors have been implicated in their development [17]. The type of vesico-urethral anastomosis plays a major role. Excessive narrowing of the anastomosis and/or lack of mucosal apposition at the time of the procedure are known risk factors [3, 10]. Ischemia of the bladder neck and/or the membranous urethra could explain higher rates in older patients with peripheral vascular disease [3]. Smoking, diabetes, hypertension, obesity, chronic renal insufficiency and coronary artery disease were also associated with anastomotic stricture in large scale observational studies [10]. Too much tension on the anastomosis could also lead to ischemic stricture formation. Postoperative radiation is another well-known cause of anastomotic stricture by inducing ischemia and fibrosis [3, 10, 29]. The single knot running technique is associated with a low (0–3 %) risk, [16, 19, 33, 41], due to several technical factors: it creates a direct wide vesico-urethral alignment with an end to end mucosal apposition, and ischemia is also reduced by the running “funneling parachute” anastomosis.

Minimally invasive radical prostatectomy is always challenging. However, there are particular situations in which the dissection and the reconstructive phase of the intervention can be particularly complex. Regarding VUA, major challenges can arise when prostatectomy is performed after another primary prostate cancer treatment (i.e., radiation therapy, HIFU, cryoablation), or after prostate surgery for benign prostatic enlargement. Indeed, these are all situations in which dissection is very complicated, particularly that of the bladder neck, as surgical planes are usually blended together and massive fibrosis is present. Frequently in these situations the bladder neck is excessively opened, with a consequent mis-match of the bladder neck and the urethra. To face this problem, the bladder neck can be reconstructed with a posterior or anterior tennis-racket. Moreover, if there has been exposure to radiation or thermal energy, tissue healing is usually impaired and the risk of post-operative complications is therefore elevated. This should be kept in mind by the surgeon, especially for what concerns urine leakage and anastomotic strictures. An in depth analysis has been performed by Ouzaid et al., who retrospectively analyzed 2215 patients undergoing LRP or RARP with the Van Velthoven technique. After a median follow-up of 43 months, anastomotic strictures occurred overall in 30 (1.4 %) patients, and both previous radiotherapy and previous transurethral resection of the prostate (TURP) were significant predictors of such adverse even [29].

Series describing functional outcomes of salvage RALP after primary treatment (radiation, brachytherapy, HIFU) confirm that complications following such procedure are frequent [4, 9, 21, 34, 45]: the largest of these series, recently published by Yuh et al., analyzed complications and functional outcomes of salvage RALP in 51 men with recurrent prostate cancer. Complication rate was elevated (25 % minor complications; 43 % major complications), and regarding anastomosis, 18 % of patients experienced a urinary leakage and 16 % an anastomotic stricture [45]. Eandi et al. also reported outcomes in 18 men undergoing salvage RALP: 33 % of patients had a leak requiring prolonged drainage (mean 38 days), and 17 % developed an anastomotic stricture [9]. As expected, post-operative continence rates were low, with 33 % of men being pad-free after a median of 7 months. Similarly, Boris et al. reported one anastomotic leakage and one stricture in a series of 11 men undergoing salvage RALP [4].

Data regarding functional results of minimally invasive radical prostatectomy after prostate surgery for benign prostatic enlargement are even scarcer than for salvage RALP. A group from India recently published a study in which 26 men with previous TURP underwent RALP, and compared them to a cohort of 132 men undergoing RALP with no history of prostatic surgery [15]. In their work the authors point out the multiple difficulties associated with RALP in these patients, as the thickening of the bladder wall (a discrepant thickness of walls of the bladder and the urethra may determine difficulties in the VUA), difficult bladder neck dissection, increased periprostatic adhesions, difficulty in individuating the ureteral orifices with increased risk of injure and poor healing of the vesico-urethral junction. Indeed they found not only increased per-operative difficulties (which reflected in an increased blood losses and increased conversion to open surgery), but also worst post-operative functional outcomes: a prolonged urine leakage and an anastomotic stricture was found in 11.5 % and 14 % of men in the post-TURP group, respectively.

Although feasible, surgeons must keep in mind that patients with prior treatment for prostate cancer or surgery for benign prostatic enlargement represent a true challenge, even for experts in the field of minimally invasive prostatectomy. Regarding the VUA, these patients present difficulties as a consequence of the frequently imperfect bladder neck conformation and of poor tissue healing, with a consequent increase in risk of anastomotic complications such as a prolonged urine leakage and a stricture.