Robotic Ureteral Bypass Surgery with Appendiceal Graft for Management of Long-Segment Radiation-Induced Distal Ureteral Strictures: A Case Series

Abstract

Introduction: Surgical management of long-segment radiation-induced distal ureteral strictures (RIDUS) is challenging. Pelvic radiation can damage the bladder, inhibiting the utilization of typical reconstruction techniques such as a psoas hitch and/or Boari flap. Also, radiation can cause scarring that can make ureterolysis difficult.

Case Presentation: We present a case series of patients undergoing robotic ureteral bypass surgery with appendiceal graft for management of strictures in this setting. This novel procedure utilizes the patient's appendix as a bypass graft to divert urine away from the strictured portion of ureter and into the bladder; this technique does not require dissection of the strictured ureteral segment.

Conclusion: Robotic ureteral bypass surgery can be effective for management of long-segment RIDUS.

Introduction

Surgical repair of long-segment radiation-induced distal ureteral strictures (RIDUS) is a challenging problem for reconstructive urologists. In the appropriate clinical scenario, a patient's appendix may be utilized as a bypass graft to redirect urine past the strictured ureter and into the bladder using a technique analogous to coronary artery bypass grafting. Herein, we describe our novel technique and report on our experience with robotic ureteral bypass surgery with appendiceal graft.

Case Presentation

We performed an Institutional Review Board-approved retrospective review of all patients who underwent robotic ureteral bypass surgery with appendiceal graft between August 2018 and May 2019. All patients developed ureteral strictures secondary to pelvic radiation for gynecologic (n = 2), colorectal (n = 1), or prostatic (n = 1) malignancies. Primary outcomes included 30-day major (Clavien >2) postoperative complications and surgical success (i.e., absence of obstruction on renal scan). Patient demographics and perioperative outcomes are presented in Table 1.

Table 1.

Patient Demographics and Perioperative Outcomes

	Gender	Age, year	Body mass index, kg/m2	Stricture location	Stricture length, cm	Operative time, minutes	Estimated blood loss, mL	Intraoperative complications	Length of stay, day	Follow-up, month	30 d Major (Clavien >2) complications	Surgical success
Patient 1	Male	45	35.9	Middle and Distal	8.0	397.0	75.0	None	3	15	None	Yes
Patient 2	Male	65	22.2	Distal	7.0	300.0	50.0	None	1	13	None	Yes
Patient 3	Female	77	23.0	Distal	4.5	208.0	100.0	None	—	—	Sudden cardiac death	—
Patient 4	Female	67	39.1	Distal	6.0	375.0	25.0	None	1	12	None	Yes

Surgical technique

All surgeries were performed using the da Vinci^® Xi Surgical System (Intuitive Surgical, Sunnyvale, USA) with integrated near-infrared fluorescence (NIRF) imaging capability. Patient positioning and port placement are shown in Figure 1. The decision to perform ureteral bypass surgery was made intraoperatively after assessing patient anatomy and stricture characteristics. This technique may be utilized when the following criteria are met:

FIG. 1.

Patients were placed in a modified lithotomy position with the table slightly airplaned to the left to elevate the right flank. Four 8 mm robotic ports and one 12 mm assistant port were utilized as shown.

• (1)A long-segment right-sided RIDUS that is not amenable to traditional reimplantation techniques because of stricture length and/or impaired bladder capacity.
• (2)The presence of an appendix that is patent, free of radiation-induced changes, and of adequate length for reconstruction.

Ureterolysis

We begin by identifying the healthy ureter within the retroperitoneum just above the level of the stricture. A dissection is performed caudally along the anterior aspect of the ureter until the strictured area is reached, taking care to preserve the incoming blood supply from the internal iliac artery and avoid traumatizing the existing longitudinal ureteral blood supply; the strictured portion remains undissected.

Bladder mobilization

Afterward, the bladder is mobilized off of the anterolateral abdominal wall. To reduce the risk of compromising the bladder's blood supply, we typically avoid traditional maneuvers for maximal bladder mobilization such as formation of a tensioned psoas hitch (PH) and ligation of the contralateral superior vesical pedicle. Instead, an absorbable suture may be placed to position the bladder lie in the direction of the anticipated reconstruction without putting significant tension on the bladder. The distance between the bladder dome and healthy ureter is then measured.

Appendix preparation

After identifying the appendix, it is visually inspected to confirm that it is free of radiation-induced changes and of adequate length. The appendix is suture ligated at its proximal (cecal) end using nonabsorbable suture and subsequently transected at the cecal junction, taking care to preserve its mesentery. We inject 1.5 mL of intravenous indocyanine green (ICG) to confirm adequate perfusion of the appendix and its mesentery under NIRF. Under NIRF perfused tissue fluoresces green, whereas devitalized tissue remains poorly or unfluoresced. The cecum is then closed in a second layer using nonabsorbable sutures in a Lembert manner. The distal end of the appendix is transected, and a guidewire is inserted into the appendix to confirm patency. We spatulate both ends of the appendix and irrigate its lumen to clear out any stool burden.

Appendiceal bypass anastomosis

A 1.5 cm longitudinal incision is made on the ventral aspect of the healthy ureter located above the stricture. Another 1.5 cm incision is made over the bladder dome. The cecum is pexed to the right abdominal wall using barbed absorbable suture to reduce tension on the appendiceal blood supply. The proximal end of the appendix is then anastomosed to the ureterostomy site in an end-to-side manner using absorbable sutures (Fig. 2A). The appendiceal graft is positioned in an antiperistaltic manner to avoid twisting of the mesoappendix. After completing half of the anastomosis, a 6-F Double-J stent is placed into the right ureter in retrograde manner. The remainder of the appendicoureterostomy is then completed.

FIG. 2.

(A) The anastomosis is made between the appendix (white dashed lines) and the right ureter (yellow dashed lines) in an end-to-side manner using two monofilament absorbable sutures. (B) The anastomosis between the appendix (white dashed lines) and bladder dome (blue dashed lines) is performed in an end-to-end manner using two monofilament absorbable sutures.

Next, the distal end of the appendix is anastomosed to the cystotomy site in an end-to-end manner using absorbable sutures (Fig. 2B). Before completing the anastomosis, the distal curl of the previously placed Double-J stent is inserted into the bladder. Finally, we inject another 1.5 mL of intravenous ICG to confirm adequate perfusion to the appendicoureterostomy and appendicovesicostomy sites (Fig. 3). The completed reconstruction enables urine to travel through the appendiceal graft and into the bladder, bypassing the strictured ureteral segment (Fig. 4).

FIG. 3.

Intraoperative images before (A) and after (B) NIRF with ICG to assess perfusion to the reconstructed anastomosis between the ureter (yellow dashed lines) and appendix (white dashed lines). Intraoperative images before (C) and after (D) NIRF with ICG is used to assess perfusion to the reconstructed anastomosis between the appendix (white dashed lines) and bladder dome (blue dashed lines). The appendiceal graft, appendicoureterostomy, and appendicovesicostomy sites, and background tissue will fluoresce green if adequately perfused. ICG, indocyanine green; NIRF, near-infrared fluorescence.

FIG. 4.

In surgical management of patients with long-segment right-sided radiation-induced distal ureteral strictures, the patient's appendix may be utilized as a bypass graft to redirect urine past the strictured ureter and into the bladder. Illustrations before (A) and after (B) robotic ureteral bypass surgery with appendiceal graft.

Discussion

Management of RIDUS poses significant surgical challenges. Traditionally, reconstruction of long-segment distal ureteral strictures in a nonradiated field involves a PH to mobilize the bladder and/or a Boari flap (BF) to create a tubularized flap. However, some authors have suggested that these techniques may not be ideal for patients with radiation-induced changes to the bladder and ureter.^1,2 Radiation may cause bladder fibrosis, inhibiting cephalad mobilization of the bladder during a PH and increasing the risk of flap ischemia during a BF. Furthermore, radiation can cause a significant reduction in bladder capacity, increasing the patient's risk of developing postoperative lower urinary tract symptoms after a BF. With regard to effects on the ureter, radiation can cause periureteral scarring and obliteration of dissection planes, making ureterolysis difficult. In addition, given the damage radiation may have on the fragile ureteral blood supply, extensive ureteral dissection during reimplantation may cause ureteral devascularization and result in unpredictable stricture elongation.

Given the challenges and risks associated with utilizing a PH and BF in a post-radiated pelvis, ileal ureter replacement (IUR) has also been utilized in this setting. Although IUR has demonstrated success in relieving ureteral obstruction, it is associated with significant morbidity. Armatys et al. found that 13/17 (76.5%) patients undergoing IUR for RIDUS experienced long-term postoperative complications, including small bowel obstruction requiring surgery (17.6%), ileal ureteroenteric (11.8%), and enterovaginal fistula (11.8%) formation requiring surgical repair, and recurrent urinary tract infections requiring antibiotics (11.8%).³

In our current series, we describe perioperative outcomes of four patients who underwent robotic ureteral bypass surgery with appendiceal graft. Three patients had strictures located in the distal ureter; one patient had a stricture extending from the middle to distal ureter. Median stricture length was 6.5 (range 4.5–8.0) cm, operative time was 337.5 (range 208.0–397.0) minutes, and estimated blood loss was 62.5 (range 25.0–100.0) mL. There were no intraoperative complications. Median length of stay was 1 (range 1–3) day. A 77-year-old woman who underwent a 208 minutes procedure unexpectedly died on postoperative day 0 from sudden cardiac arrest secondary to a spontaneously ruptured plaque in her right coronary artery. The patient did not have an extensive cardiac history and her Gupta Myocardial Infarction or Cardiac Arrest risk was 0.52%. The remaining three patients underwent Double-J stent removal at 8 weeks postoperatively and have not experienced any major postoperative complications. At a median follow-up of 13 (range 12–15) months, 3/3 (100.0%) patients were surgically effective.

When appropriately indicated, ureteral bypass surgery may offer significant advantages for reconstruction of long-segment right-sided RIDUS. The benefits of using an appendiceal graft, compared with ileum, for ureteral reconstruction have been highlighted by prior studies.⁴ Given the smaller surface area of the appendix compared with ileum, utilizing an appendiceal graft results in negligible urine absorption and lowers the risk of developing metabolic abnormalities. Furthermore, the appendix is similar in caliber to the ureter. Using the appendix also obviates the need for a bowel–bowel anastomosis, thus decreasing the risk of bowel-related complications.⁴ In addition to the advantages of using an appendiceal graft, this technique is particularly useful in the setting of a radiated pelvis as it decreases the need for extensive ureteral manipulation. Ureteral bypass surgery only requires enough ureterolysis to make a longitudinal incision along the healthy ureter to facilitate an end-to-side appendicoureterostomy. By avoiding dissection of the strictured segment, this technique may reduce the risk of ureteral devascularization.

Although our results suggest that ureteral bypass surgery may be effective for repair of long-segment right-sided RIDUS, we must emphasize that this technique should only be utilized when traditional ureteral reimplantation techniques are infeasible and when the patient's appendix is suitable for reconstruction. In addition, given the technically difficult nature of the procedure, patients must be preoperatively counseled on the risks of undergoing a potentially long operation.

Conclusion

Robotic ureteral bypass surgery with appendiceal graft is a novel technique that can be utilized for management of long-segment right-sided RIDUS.

Abbreviations Used

BF

Boari flap

ICG

indocyanine green

IUR

ileal ureter replacement

NIRF

near-infrared fluorescence

PH

psoas hitch

RIDUS

radiation-induced distal ureteral strictures

Disclosure Statement

M.L. and Z.L. have no competing financial interests. M.J.M. is a consultant and speaker for Endo Pharmaceuticals, Coloplast, and Boston Scientific. D.D.E. is a paid speaker, consultant, and proctor for Intuitive Surgical, a consultant for Johnson and Johnson, performs support for trainees for Hitachi Aloka, and is a founder/part owner of Melzi Corp.

Funding Information

No funding was received for this article.

Cite this article as: Lee M, Lee Z, Metro MJ, Eun DD (2020) Robotic ureteral bypass surgery with appendiceal graft for management of long-segment radiation-induced distal ureteral strictures: a case series, Journal of Endourology Case Reports 6:4, 305–309, DOI: 10.1089/cren.2020.0105.