Robot-assisted ureteral reconstruction - current status and future directions.

Robotic platforms have revolutionized the practice of urology. The widespread dissemination of this technology has resulted in greater patient treatment choice for various surgically treatable diseases. Ureteral reconstruction is an area of urology which has shown great benefit from robot-assisted techniques due in part to the intricate surgical manipulation required for successful completion in these operations. The robotic platform has the benefit of better three-dimensional visualization, tremor reduction, finer control, less blood loss, and shorter hospital stay. In the many cases of ureteral reconstruction where no or small pathology specimens are extracted, there is little need to extend existing incisions, which contributes to better cosmetic outcomes. Currently, short- and intermediate-term outcomes from robotic ureteral reconstruction are largely found in the literature, but with increasing adoption of this technology, there will be more long-term outcomes forthcoming. This article reviews robot-assisted surgical techniques for ureteral reconstruction. Specific attention will be given to procedures such as ureterolysis with omental wrapping, ureteroureterostomy, buccal mucosa graft (BMG) ureteral stricture repair, ureteral reimplantation, ileal ureter, and use of the robot in pediatric ureteral reconstruction.

Although the robotic platform was initially used in adult urologic surgery, pediatric urologists have also adopted robotic surgery for extirpative and reconstructive procedures. While pyeloplasty is the most commonly performed pediatric robotic surgery, Bowen et al . have reported that robotic ureteral reimplantation is becoming increasingly popular, representing approximately 5% of all pediatric ureteral reimplantations by 2012.[ 47 ] The “gold standard” repair for vesicoureteral reflux is either intravesical or extravesical open surgery, with success rates >95%. Robotic ureteral reimplantation is most feasible extravesically, by recreating the Lich-Gregoir technique.[ 48 ] Smaller, single institution reports note success rates similar to open, but larger single institution and multi-institution studies demonstrate success rates between 70% and 90%.[ 49 50 51 52 53 ] This large difference in outcomes is commonly attributed to technique and learning curve, but examination of the literature shows differences from surgeon to surgeon in terms of the procedure. In general, the patient is positioned in the dorsal lithotomy position, and the robot is docked between the legs of the patient. The camera port (8–12 mm) is placed at the umbilicus or 1 cm infraumbilically and working ports (5 mm or 8 mm) are placed lateral or slightly inferolaterally to the camera port in the midclavicular line, at the level of the anterior superior iliac spine or even lower in larger children.[ 49 52 54 55 ] An assistant port may or may not be utilized. The bladder and ureters are accessed with a transperitoneal approach and the ureters are identified and mobilized distally to the ductus deferens or uterine artery. Cautery must be used with precision to minimize thermal injury to periureteral tissue and the neurovascular bundle, a theorized cause of postoperative urinary retention.[ 48 ] Classically, a detrusorotomy that is five times the ureteral diameter is created; elevating the bladder anteriorly through a suprapubic hitch stitch may be of assistance. The ureter is subsequently placed in the submucosal detrusor tunnel, with the detrusor musculature closed over the ureteral in a continuous or interrupted fashion.[ 52 54 ] Gundeti et al . have reported on the LUAA technique, a series of modifications implemented over a 7-year period in 83 ureters to improve VUR resolution rates from 67% to 87%.[ 52 ] This includes a detrusor tunnel length of 4–5 cm regardless of ureter caliber (L), placing a U-stitch at the distal end of the Y-shaped detrusorotomy to advance the ureter (U), aligning the ureter in the detrusor tunnel with a permanent apical stay stitch (A), and incorporating adventitia in every other throw of the continuous detrusorraphy (A). Overall, the body of evidence presents in the literature supports the use of the robotic platform for ureteral reimplantation in the pediatric population.

Robotic platforms have provided an impetus for innovation in surgery while preserving patient safety and postoperative outcomes. Ureteral reconstruction has shown great benefit from use of the robot with the fine tissue manipulation required and the promise of improved cosmesis and minimal blood loss. The aforementioned robot assisted procedures are efficacious in experienced hands and are an option to counsel patients about when discussing surgical avenues for ureteral reconstruction. Nil. There are no conflicts of interest.

All patients undergoing robotic ureteral reconstruction will undoubtedly benefit from a thorough history and physical examination. Care should be taken to understand the cause for ureteral disease – whether it be congenital, iatrogenic, or autoimmune. To aid in the successful and expeditious completion of robotic ureteral reconstruction, it is imperative to have appropriate imaging. A computed tomography (CT) or magnetic resonance (MR) urogram should provide adequate anatomical detail for surgical planning. In some cases which may preclude intravenous contrast administration (allergy, kidney disease etc.), a retrograde ureterogram and ureteroscopy can provide important anatomic detail. In cases of suspected long-standing ureteral stricture, a diuretic renogram can characterize differential renal function and confirm the presence of obstruction. If there is minimal function in the affected renal unit, one can forego stricture repair. An important part of the preoperative assessment involves a comprehensive informed consent. Attention should be given to explaining the pathophysiology of the patient's disease and the prospect of disease recurrence. Furthermore, the surgeon should discuss the chance of operative and postoperative complications and the possibility of secondary or reoperative procedures.

Ureteral identification can be one of the most difficult parts of the procedure, especially in the case of robotic surgery as there is an absence of tactile feedback. Ureteral inflammation secondary to the pathology of the case and periureteral fibrosis can make ureteral identification challenging as surgical planes can be distorted. However, the outcome of a ureteral stricture case depends on this critical identification step. Excision of the entire diseased segment of ureter prevents stricture recurrence, but resection of unnecessary healthy tissue can lead to inadequate ureteral length and a tensioned anastomosis, which may be prone to stricture or breakdown. Assessment of preoperative imaging is necessary to having a roadmap for the identification of the ureter with respect to surrounding structures. Identification maneuvers (such as clamping the Foley placed preoperatively and administration of a diuretic) before dissection can help with distention and increased peristalsis of the ureter, which will aid in ureteral identification. Large ureteral masses, either intraluminal or extraluminal, are generally identifiable through intraoperative inspection. Smaller ureteral masses are more difficult to identify with robotic vision alone, but several techniques exist to assist the surgeon. For one, endoscopic techniques can be employed before the robotic aspect of the case. Options include concurrent ureteroscopy, where the surgeon guides an open ended catheter to the level of light seen. Another newer option is the use of near-infrared fluorescence imaging.[ 1 ] Indocyanine green is injected intraureterally and can be visualized under near-infrared fluorescence to help identify the proximal and distal limits of a ureteral stricture in a efficacious manner.[ 1 ]