Lower Ureteral Reconstruction: Robotic Surgery

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Lower Ureteral Reconstruction: Robotic Surgery

S. Duke Herrell

Vanderbilt University Medical Center, Nashville, TN, USA

Introduction

Obstruction of the lower ureter requiring reconstruction can take place from a variety of extrinsic and intrinsic causes, including both non‐iatrogenic and iatrogenically induced strictures. In addition, diseases such as reflux and other bladder‐related issues, such as diverticuli, might necessitate ureteral reimplantation. The treatment paradigm for distal ureteral obstruction evaluation and treatment should be well known to most practicing urologic surgeons. The evaluation of distal ureteral obstruction is often focused at attempting to delineate the causal events. Workup and evaluation of the various differential diagnoses are beyond the focus of this chapter.

Urologic surgeons may bring varied skills, including endourologic, laparoscopic, robotic, and open surgery, to bear on the complexities of distal ureteral obstruction. A standard underlying tenet of care is the appreciation and relief of complete or marked obstruction to prevent significant ongoing renal nephron functional loss. This may involve the use of temporizing endourologic and radiologic interventions such as ureteral stent placement or percutaneous nephrostomy tubes to relieve obstruction. Especially in cases where significant obstruction exists or there is evidence of longstanding hydronephrosis and parenchymal loss, the urologic surgeon should also employ selected radiologic studies such as computed tomography (CT) and nuclear scans to evaluate the overall functional status of the kidney prior to undertaking reconstructive surgery. In cases where the kidney is of minimal function, typically less than 15% with a normal contralateral kidney, nephrectomy should be considered in appropriate patients if symptoms or complications such as pain, infection, hematuria, or significant renal‐based hypertension are found and necessitate intervention.

Specific cases such as bladder tumors causing local invasion and obstruction of the ureter as well as distal ureteral tumors are beyond the scope of this chapter and are managed according to standards of oncologic practice. In certain distal ureteral tumor scenarios, utilization of reconstructive efforts described in this chapter, such as either psoas hitch or Boari flap, follow the standard approach as noted below when oncologically appropriate [1, 2]. Techniques differ from benign stricture disease as the distal ureter is usually completely removed and surgeons are encouraged to utilize caution in the approach to distal ureteral tumors as implantation of tumor remains a risk for this often aggressive disease.

This chapter describes the robotic and laparoscopic options for managing common distal ureteral obstruction scenarios. Readers are encouraged to review other sources as to the etiology, diagnosis, and indications for management in specific disease processes. This chapter will concentrate on surgical technique for laparoscopic and robotic approaches to distal ureteral reconstruction.

Diagnostic evaluation

The evaluation of distal ureteral stricture disease, especially if no causative factors are apparent, should include the process of ruling out the presence of intrinsic or extrinsic malignancy. Distal ureteral stricture disease is often related to stone disease. Although endoscopic treatments for stone disease have advanced, the presence of long duration impacted stones as well as iatrogenic damage to the ureter can still cause ureteral stricture. Additional causes of benign ureteral strictures are numerous and include pelvic radiation for a variety of malignant pelvic disease processes, infection, endometriosis, trauma, and inflammatory disease, such as retroperitoneal fibrosis and pelvic lipomatosis.

Modern diagnostic studies typically include CT urogram as well as potentially retrograde or antegrade pyelography combined with endoscopic evaluation performed prior to definitive intervention. At the time of this endoscopic evaluation, the status of the bladder, especially in patients who have neurogenic bladder or other potential complicating factors such as radiation to the pelvis, should be assessed as to the bladder tissue’s potential suitability as a ureteral substitute if necessary. In some selected scenarios, endoscopic intervention such as endoureterotomy can be employed for short strictures to avoid ureteral reimplantation or reconstruction. Endoscopic incision is typically only successful for strictures less than 2 cm without underlying tissue compromise by radiation. Use of endoureterotomy via both antegrade and retrograde approaches is discussed in other chapters within this text.

Some contraindications to procedures such as psoas hitch and/or a flap include the presence of significant bladder outlet obstruction, neurogenic dysfunction, or significant reduction in bladder capacity or tissue mobility. In these circumstances consideration of other repair methods such as ileal interposition, autotransplantation, or even urinary diversion may be warranted.

Basics of surgical repair

A variety of techniques are available to reconstruct distal ureteral obstruction. Urologic surgeons should be familiar with each of these techniques and their potential use as well as indications and contraindications in different patterns of ureteral length loss. In most surgical situations the intrinsic involvement of the ureter has been assessed prior to surgical intervention with radiologic and endoscopic evaluation. The general tenets of open surgery that have existed for decades underlie the choice made for reconstructive efforts in distal ureteral obstruction and have been emulated in modern robotic and laparoscopic procedures. Preoperative assessment will often give clues to the length of ureter involved with the stricture process that will need to be bridged in some manner to reach the bladder or perform a primary anastomosis. Historically, most disease processes involving the distal ureter have been defined as the pelvic brim to the bladder. Most “distal” strictures have been approached with reimplantation of the ureter directly into the bladder via either mobilization of the bladder (psoas hitch) for use of a flap of bladder tissue (Boari flap) [3–5]. In rare cases, primary ureteroureterostomy might be feasible but is typically more employed for the upper or mid ureter. Lower ureteral stricture repair is best managed by reimplantation into the bladder when feasible.

The length of ureter involved by stricture and damage differentiates the various surgical techniques. Urologic surgeons should be knowledgeable about the typical length gained by employing these maneuvers. Surgical maneuvers and techniques such as ureteroureterostomy (length of ureteral involvement is 2–3 cm), ureteroneocystostomy (length 4–5 cm), psoas hitch (length 6–10 cm), and Boari flap (length 12–15 cm) are often employed. Typically, for distal strictures, reimplantation into the bladder is the preferred management paradigm. Additional techniques such as renal mobilization with nephropexy (renal descent) can provide an additional 5–8 cm of ureteral length, but this is typically mainly useful for mid‐ureteral and upper ureteral strictures [6]. In certain cases renal mobilization with nephropexy can aid in the performance of an especially long Boari flap type repair. Additional procedures that can be employed for even more significant ureteral length loss such as transureteroureterostomy, ileal ureter, buccal ureteral graft, and autotransplantation are available and reviewed in multiple publications throughout the urologic literature [7, 8]. There has been some literature experience with performing these procedures with laparoscopic or robotic approaches but these have been relatively limited in number and experience to date [9–12].

General concepts

Surgical scenarios

In many of the surgical scenarios, the precise type of repair to be employed will not be completely understood until a full dissection of the surrounding structures and identification of the length of ureter involved with stricture and damage which needs bypassed or replaced is understood. Unfortunately at times the ureter may be more involved than originally anticipated. One of the key tenets of ureteral repair surgery is that, similar to urethral repair, diseased tissue is removed until good, viable, full‐thickness tissue with blood supply is encountered. Even if this involves conversion to a more extensive repair procedure the success rate is highest when tissues with excellent blood supply make up both sides of the anastomosis site. Informed consent should be obtained for all potential procedures, including psoas hitch, Boari flap, ureteral replacement, and even possible autotransplantation. Certainly for extensive or long strictures the patient should be aware of the potential to need a larger or more complex procedure.

Patient preparation

A patient’s preparation is performed depending on the clinical scenario and follows the typical evaluation for major urologic surgery. We typically employ a mild preoperative bowel prep to aid with bowel decompression. In patients with history of extensive previous transabdominal surgery consideration should be given to full bowel prep if the potential of enterotomy is high and depending on institutional standards. In addition, if the stricture is long and the potential exists for ileal interposition, a more complete bowel preparation may be considered. Standard preoperative preparation is performed as per institutional and physician protocol.

Preoperative presence of drains and tubes

In our practice, we typically remove the ureteral stent 4–6 weeks prior to the proposed repair if one is indwelling. If it is a more complete obstruction or the patient has significant obstructive pain then a percutaneous nephrostomy tube is placed ipsilateral. In our experience the ability to differentiate healthy ureteral tissue is enhanced by the removal of an indwelling stent several weeks prior to the proposed procedure, similar to the removal of transurethral catheters prior to urethroplasty surgery.

Intraoperative

Position and preparation

Patient positioning for the majority of distal ureteral surgeries has the patient placed in a standard low lithotomy supine position similar to standard robotic pelvic surgery. Standard preparation for laparoscopic‐based surgery includes an orogastic tube and a Foley catheter, which is placed transurethrally sterilely onto the field. In addition, if a nephrostomy tube is present we typically connect this to tubing extenders so that injection and irrigation are possible.

In some cases the complexity of the previous abdominal surgeries, operative field, or situation may necessitate the urologist perform a cystoscopy and place a retrograde ureteral stent and wire to aid in finding the ureter. This is possible only if the ureter is patent distally. For the majority of repairs, this is not necessary. In specialized procedures for distal ureteral tumors, the urologist may wish to perform cystoscopy to ensure that the bladder is free of any tumor or extensive progression of the distal ureteral tumor, depending on the oncologic scenario

Entry and port placement

For both robotic and laparoscopic repairs, standard abdominal entry techniques and port placement geometry are employed. We currently perform the majority of these repairs robotically as it aids in suturing, especially for complex flap repairs etc. Although we have had extensive experience in performing these with pure laparoscopic techniques in the decade prior, there is no doubt in our opinion that the suturing, while feasible laparoscopically, is made easier to both perform and learn with the robot.

We typically employ all four arms of the robot. The fourth arm can be placed either ipsilateral or contralateral depending on surgeon preference. A 12 mm assistant port is placed opposite the fourth arm. Standard port configuration for pelvic surgery is employed, although typically the trocars are moved more cephalad (2–5 cm superior to the umbilicus), especially for more extensive flap type repairs (Figure 117.1). With the newer da Vinci™ Si and Xi platforms (Intuitive Surgical Inc., Sunnyvale, CA, USA) the ability to extensively move quadrants within the abdomen aids in performance of these procedures. Especially in reoperative or iatrogenically caused injuries, surgeons may be required to perform extensive adhesiolysis to gain exposure to the pelvis, ureter, bladder, and the site of injury. In some scenarios mobilization of the kidney may be necessary, making patient positioning and repositioning more complex. Conversion to open surgery may be required. All surgeons undertaking these types of reconstructive efforts should be well versed in laparoscopic, robotic, adhesiolysis, and versatile repair techniques.