Robot-Assisted Surgery in Urology: The Show Must Go On

Initially, robot-assisted surgery (RAS) was developed by the USA forces as a tele-surgery tool in order to perform procedures in war zones without endangering the surgeon [1]. The first clinical trials on RAS were carried out by cardiac surgeons, then by specialists in other fields like ear nose and throat, gynecology, colorectal, thoracic, maxilla-facial, and urology. Since its introduction into clinical practice, RAS has achieved increasing success: From the first pioneering platforms, it evolved into the current 4500 individual systems of many different developmental generations used worldwide as of June 2018. According to data from North American population-based registries and European academic institutions, the robotic approach is currently applied in more than half of patients undergoing intervention for prostate, kidney, and bladder carcinoma [2]. RAS consents to maintain the benefits of laparoscopy with additional advantages including magnification of the operative field due to three-dimensional vision, greater accuracy due to EndoWrist^® instruments (Intuitive Surgical Inc) with seven degrees of motion, primary surgeon camera control, and tremor filtration. The main disadvantages are the lack of haptic feedback and the high costs. However, this technology permits the reproduction of the same surgical step of open surgery with the benefits of a minimally invasive technique, overcoming the limitations of the laparoscopy: in particular, RAS can reduce physical strain and simplify the learning curve. For these reasons, RAS has become the gold standard approach for the treatment of many urological diseases. In particular, the robotic technique achieves the greatest results when used in the treatment of prostate cancer; robot-assisted radical prostatectomy (RALP) has already replaced open and laparoscopic radical prostatectomy, ensuring exiting results in terms of intraoperative blood loss, transfusion rates, duration of catheterization, length of hospital stay, readmission rates, but above all for what concerns potency and urinary continence recovery. Concerning functional outcomes, these results are due to the better visualization of vascular and nervous structures and more accurate dissection: This allows better preservation of anatomic components that control potency and urinary continence [3,4]. Radical cystectomy (RC) is the gold standard treatment of muscle-invasive bladder cancer and BCG resistant non-muscle-invasive one [5]. Although traditional surgery remains the standard approach, RAS is being increasingly used. Recently, Novara et al. performed a systematic review and meta-analysis comparing open RC with RAS. They found similar oncologic outcomes in terms of positive surgical margins, overall survival, cancer-specific survival, and recurrence-free survival; compared to open RC, RAS RC showed longer operative time and 1 to 1.5 days shorter mean length of hospital stay. Intra-operative, 30-day complication rate and mortality were similar, but grade 3, 90-day, complication rates favored robotic technique. Blood loss was lower and, consequently, the transfusion rate was significantly lower in robotic RC and this is due to a better visualization of the operative field and more accurate dissection in debulking time of intervention [6]. Although these exciting and promising results, robotic RC is reported in the European Association of Urology Guidelines as an experimental procedure.

Concerning kidney surgery, RAS provides no advantages with respect to laparoscopy when radical nephrectomy should be performed. Conversely, for partial nephrectomy that is the gold standard treatment of T1 renal tumor, RAS has significant advantages with respect to laparoscopy. Recently Leow et al. performed a systematic review of the literature and meta-analysis and they found robotic partial nephrectomy decreased complications, conversions to open, positive surgical margin and ischemia time [7]. During partial nephrectomy it can be necessary to induce a renal ischemia and the length of ischemia time is a key point for possible postoperative renal damage. Nevertheless, many different laparoscopic techniques of partial nephrectomy are reported in the literature and it has now been demonstrated that in some cases renal ischemia could be carried out only on demand [8]. Conversely, in robotic partial nephrectomy the ischemia time is always applied. However, postoperative renal damage may be due to the quantity of preserved healthy parenchyma. Although there are no trials evaluating the possible relation between the type of suture, remaining healthy tissue, and postoperative renal function, we feel that RAS can perform a more accurate suture of resection bed with respect to laparoscopy and this could reduce the damage of preserved healthy tissue.

Similarly, we believe that the accuracy of the robotic suture can improve the functional outcome of the pyeloplasty with respect to laparoscopy. Robot-assisted pyeloplasty has shown excellent results with a success rate ranging from 94 to 100%. However, Autorino et al. performed a recent systematic revision of the literature and meta-analysis comparing clinical outcomes of 277 robotic pyeloplasties with 196 laparoscopic ones. The authors found no significant differences between the two procedures except shorter operative time for the robotic technique [9].

Concerning adrenal surgery, the laparoscopic approach is the standard procedure. Nevertheless, many trials showed exciting results when the adrenalectomy was performed using the robotic technique. We feel that RAS is very useful to perform both radical and partial adrenalectomy thanks to the magnification of the operative field and a more accurate dissection. These advantages allow more careful detection of the adrenal vascular pedicles, as well as identification of the cleavage plane between the tumor and healthy tissue [10]. A recent meta-analysis comparing the traditional and robotic or laparoscopic adrenalectomy, showed a reduction of blood loss and length of hospitalization with RAS [11].

In conclusion, because of the increasing diffusion of RAS and the continuous technological innovations in the urological field, indications for the applications of RAS will be further extended. Recently, many studies reported the safety and feasibility of robotic treatment of metastasis, paraganglioma, colovesical fistula, retroperitoneal lymph nodes as well as robotic renal transplantation [12,13,14,15,16]. Mostly in the field of uro-oncology, the future perspective will be to reach an earlier diagnosis of urological tumors due to the development of new and more accurate biomolecular markers [17,18,19,20,21]. Therefore, an early diagnosis helps to treat a greater number of localized masses by less destructive surgery such as RAS and likewise oncologically safe.