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Laparoscopic reconstruction of ureteral strictures involving solitary renal units-1 year and 5 year outcomes

Abstract

Context :
Long-term outcome following a laparoscopic reconstruction of ureteral strictures (US) involving solitary renal units (SRU) are scarcely reported. Aims: The aim was to report short-term (1 year) and long-term (5 years) outcomes following a laparoscopic reconstruction of US in a solitary kidney. Settings and Design: Retrospective. Materials and Methods: Records of patients operated for similar scenarios between January 2004 and January 2014 were evaluated. Clinical, biochemical and radiological profile were noted. Operative and post-operative profile were recorded. Follow-ups were scheduled at regular intervals (3 months post-procedure, 6 monthly for 2 years and yearly thereafter. Imaging was repeated at yearly intervals). Outcome was assessed by comparing pre-operative and post-operative clinical, biochemical, and radiological parameters. Statistical Analysis Used: SAS software 9.2 version. A P < 0.05 was inferred as statistically significant. Results: Seven patients underwent a laparoscopic reconstruction. Stricture location was upper ureter (n = 1), mid ureter (n = 2), lower ureter (n = 4). Surgeries performed were ureteroureterostomy, Boari flap ureteroneocystostomy and ureteroneocystostomy with psoas hitch. Four patients reported prior contralateral nephrectomy. Three patients underwent prior endoscopic correction. Four patients presented with elevated serum creatinine (>1.4 mg/dl). Till last follow-up, improvement in symptomatology and improvement or stabilisation of serum creatinine was perceived in all. Ureteral patency with resolution of hydronephrosis was observed in five patients at 1 year follow-up. Two patients revealed ureteral patency with persistence of hydronephrosis. Clinical, biochemical and radiological outcomes were maintained till long-term follow-up. Conclusion: Laparoscopic reconstruction of US in SRU offers impressive short- and long-term outcome.

Introduction

Ureteral strictures (US) affecting solitary renal unit (SRU) are uncommonly encountered in clinical practice. [1],[2] These patients require early definitive intervention with optimum restoration of ureteral patency to ensure renal salvage. In addition, these patients may present with deranged renal profile or report previous unsuccessful restorative attempts that may negatively impact the outcome following definitive reconstructions. Ureteral reconstructions have been traditionally undertaken through open approach and now increasingly performed through minimally invasive approaches such as laparoscopy and robot-assisted laparoscopy. [3],[4] Although minimally invasive approaches offer better morbidity profile, the operator needs to be versed with these techniques, have considerable familiarity with anatomy and hold expertise in intracorporeal suturing. In comparison to robotic assisted laparoscopy, pure laparoscopy has technical limitations such as limited degrees of freedom, compromised dexterity and the absence of three-dimensional image that may hinder precise reconstruction and affect outcome. [5] However, due to limited availability of robotic facility and cost involved in robotic surgeries, in several centres worldwide, the pure laparoscopy continues to be offered as the sole minimally invasive approach. There is a paucity of data in current literature regarding long-term outcome following laparoscopic reconstructions for US in SRU with or without deranged renal profile at presentation. We report the short- and long-term outcome in such scenarios

Materials and Methods

Patients with SRU, who underwent laparoscopic reconstructive procedures for US between January 2004 and January 2014 comprised the patient cohort. Permission was obtained from Institutional Review Board. Data were collected retrospectively. Pre-procedure evaluation included assessment of presenting complaints, previous clinical profile and previous surgical intervention. Routine blood investigations and renal function assays were carried out. Ultrasound was performed in all cases. Additional imaging included intravenous urography or computed tomography urogram (CTU) in patients with normal renal profile and magnetic resonance urogram (MRU) in patients with altered renal profile at presentation. Pre-operative diuretic renogram (DR) was also obtained. Prior to definitive reconstruction, cystoscopy was performed to rule out vesical pathologies and assessment of vesical capacity (for feasibility of Boari flap in indicated scenarios). Retrograde pyelogram was performed for reconfirmation of length and location of pathology. Stricture was classified based on anatomical location of pathology – lower ureter (distal to sacroiliac joint to vesicoureteric junction), middle ureter (over the sacroiliac joint) or upper ureter (above the sacroiliac joint to pelviureteric junction).
Operative Plan
Definitive surgery was planned based on US location and length. Patients presenting with lower US and length ≤3 cm underwent laparoscopic ureteroneocystostomy with psoas hitch (LUNC + PH). Patients with mid US or upper US with length >1.5 cm and lower US with length >3 cm underwent laparoscopic Boari flap (LBF) with PH. Patients with mid or upper US and length ≤1.5 cm underwent laparoscopic ureteroureterostomy (LUU). Patients underwent temporary urinary diversion (percutaneous nephrostomy) prior to definitive correction.
Operative Exercise
Transperitoneal access was attempted in all cases. Three ports were utilized in all cases – one 10 mm camera port and two 5 mm working port. One additional 5 mm port was used if needed to facilitate retraction of tissues. Upper US reconstructions were undertaken in the lateral decubitus. Mid and lower US reconstructions were undertaken in trendelenburg decubitus with ipsilateral tilt.
Laparoscopic Ureteroureterostomy
Ureteric anatomy was defined and pathological segment delineated. Dismemberment, exclusion of the culprit segment, spatulation of opposite ends and tension free reunion remained the subsequent exercises. Meticulous attention was paid to the preservation of periureteral vascularity and optimum spatulation was conducted to ensure a wide anastomosis. If tension was apprehended during ureteroureterostomy, the entire renal unit was mobilised following the intra-Gerotas’ fascia plane and displaced caudally. A double J ureteral stent was inserted.
Laparoscopic Ureteroneocystostomy with Psoas Hitch
Ureteral mobilisation was started at the level of the iliac crest and continued till the pathologic segment preserving generous adventitia. Ureter was dismembered at the distal healthiest segment. Ureter end was adequately spatulated. Urinary bladder was filled with 200 ml of normal saline and anterior and lateral attachments released. Ease of approximation of vesical unit to lower ureter was ascertained. Post-erolateral vesical wall was anchored to ipsilateral psoas muscle followed by button hole cystostomy. Ureterovesical approximation was then conducted with interrupted absorbable sutures. A double J stent was inserted.
Laparoscopic Boari Flap
Following ureteric mobilisation, dismemberment and spatulation, the vesical unit was mobilised and anchored to ipsilateral psoas muscle. Thereafter, a wide posterior-based bladder flap of length commensurate to bridge ureterovesical defect was elevated preserving inflow from superior vesical pedicle. The bladder flap was unfolded to reach the ureter edge. Approximation of ureter edge to flap apex, stent insertion, tubularization of remaining bladder flap and closure of bladder defect were subsequent steps.
Post-operative Period and Follow-up
Operative and post-operative details were recorded. Nephrostomy was removed intraoperatively. Renal profile was assessed on first post-operative day and then at subsequent follow-ups. Ureteral stent was removed 6 weeks post-procedure. First follow-up was scheduled at 3 months post-procedure. Subsequent follow-up protocol included 6 monthly revisits for 2 years and yearly, thereafter. At each follow-up, clinical parameters, renal profile and ultrasound were evaluated. CTU or MRU and DR were repeated at 1 year post-procedure and yearly, thereafter.
Outcome Analysis
Pre-operative and post-operative clinical, biochemical and radiological profile were compared. Complete resolution of symptoms was considered clinical recovery. Stabilisation of serum creatinine in patients with normal pre-operative creatinine and normalization of creatinine in patients with pre-operative elevated serum creatinine was considered biochemical recovery. Resolution of hydronephrosis with unobstructed drainage pattern at follow-up imaging was considered radiological recovery. A combination of clinical, biochemical and radiological recovery was graded as complete recovery.
Statistical Interpretation
Statistical analysis was performed using SAS software 9.2 version. A P < 0.05 was inferred as statistically significant. ¤ Results Top Demographic details are projected in [Table 1]. Presenting complaints were flank pain (five patients), recurrent urinary infection (five patients) and intermittent haematuria (one patient). Mean duration of symptoms was 8.4 ± 0.4 months (range: 6-22 months). Four patients reported prior contralateral nephrectomy. History of previous ipsilateral endoscopic stone extraction was reported in four patients. One patient reported prior history of affection with genitourinary tuberculosis (completed medical management as per standard norms) and one patient reported previous laparoscopic hysterectomy. Stricture location was upper ureter (n = 1), mid ureter (n = 2), lower ureter (n = 4). Mean stricture length was 1.75 ± 0.4 cm. Four patients (one patient with upper US, one patient with mid US, two patients with lower US) presented with deranged renal profile (serum creatinine >1.4 mg/dl). Prior endoscopic correction for US was reported in three patients – balloon dilatation and stenting (two patients) and endoscopic ureterotomy and stenting (one patient). Definitive procedures could be completed via laparoscopic access in all. The surgeries included LUU (two patients), LBF (two patients) and LUNC + PH (three patients). The operative, post-operative and follow-up profile are depicted in [Table 2]. There were no remarkable intraoperative events. A significant elevation was noted in mean first post-operative day creatinine from pre-procedure values (P – 0.00). Two patients experienced post-operative stent induced dysuria, and one patient reported post-operative urinary tract infection. Mean follow-up duration was 26.2 months (range: 19-60 months). [Table 3] highlights the short- and long-term outcomes. Till last follow-up, all patients were asymptomatic. Five patients reported normal post-operative renal parameters till last follow-up. In two patients, till last follow-up, serum creatinine remained persistently elevated. Although there was no significant difference between mean pre-operative and the last follow-up creatinine (P – 0.07, t-test), a significant improvement was remarked in mean last follow-up glomerular filtration rate in comparison to the pre-operative profile (P – 0.00, t-test). Complete radiological recovery was obtained in five cases. In two cases, there was downgrading of hydronephrosis with preservation of ureteral patency and unhindered drainage pattern. Complete recovery (clinical, biochemical and radiological) was obtained in five patients (70%) till last follow-up. No patients required any intervention during the intervening period.

Discussion

Ureteral strictures commonly result from diverse aetiologies including ureteral stone impaction with localized ischemia, iatrogenic insult during endoscopic urologic procedures, open or laparoscopic surgery, radiation therapy with consequent endarteritis and penetrating traumatic injuries. [6],[7] Most patients in our cohort reported prior endoscopic intervention for calculi. Ischemia at stone impaction site or mechanical trauma to ureter during endoscopic treatment may have been responsible for resultant US in these scenarios. In all these cases, the presentation was delayed after the initial endoscopic surgery which suggests the occurrence of unrecognized insult in these scenarios that progressed over a period of time. Ureteral affection in genitourinary tuberculosis is a well-recognized association. [8] One patient in our cohort reported prior history of genitourinary tuberculosis. Despite adequate medical management and multiple endoscopic dilatations patient experienced progressive US. Ureteral patency was restored following definitive reconstruction. A variety of insults to the ureter has been reported during laparoscopic gynecologic surgeries including transaction, obstruction, fistula formation or necrosis from thermal injury. [9] One patient in our cohort presenting with lower ureteric stricture reported prior laparoscopic hysterectomy 4 months prior. In one patient, no definite aetiology was revealed, and post-operative histopathology revealed idiopathic fibrosis.
Several restorative options have been advocated for the management in US-endoscopic balloon dilatation and stenting, endoscopic ureterotomy and stenting, ureteroureterostomy, ureteroneocystostomy, Boari flap, ileal interposition and autotransplantation. [10],[11],[12] Endoscopic approaches have been reported with mixed outcomes. [13] Three of our patients (42.86%) reported prior unsuccessful attempts of endoscopic correction and hence we did not resort to this modality of correction. Although ileal interposition or autotransplantation [14],[15] has been practiced by some operators in these situations, in view of technical difficulties and limited experiences with minimally invasive approaches for a bowel interposition or autotransplantation we did not opt for these options in our patient cohort. Laparoscopic or robot-assisted LUU, ureteroneocystostomy or Boari flap are well-established procedures with good reported outcomes in the present literature. [16] In addition, our operating team is more familiar with these options [17],[18] and hence we resorted to these procedures in these cases. Certain issues need to be addressed to ensure satisfactory reconstruction of US in these scenarios. In patients with long standing pathology and previous multiple interventions, extensive fibrosis may be encountered that hinders adequate mobilisation and delineation of the pathological segment. Familiarity with laparoscopic anatomy is mandatory. Preservation of optimum vascular inflow to the salvageable segments of the ureter is also crucial. This goal may be achieved by meticulous preservation of the periureteral adventitia during ureteric mobilisation and limited usage of thermal energy. Following exclusion of the pathological segment, every effort should be made to ensure a tension free reunion of the healthy margins. In short segment upper ureteral pathology, we mobilised the renal unit well with caudal displacement to ensure tension free ureteroureteral approximation. In mid and long lower ureteric pathologies, bladder flap was created with the proper dimension and preserving vascularity to bridge the ureterovesical defect. In short segment lower ureteral pathologies, the ease of approximation of the dismembered healthy segment to the vesical unit was assessed prior to embarking on ureteroneocystostomy. Additional psoas anchorage of the vesical unit was undertaken to avoid anastomotic tension. Adequate capacity and pliability of vesical unit are also crucial for these reconstructions and optimum mobilisation of the vesical unit prior to anastomosis facilitate tension free reunion. Apart from proficiency in tissue handling and reasonable experience in dealing with these pathologies, the operator also needs to be versed with intracorporeal suturing exercises. The sutures should incorporate adequate healthy mucosa on either side to ensure satisfactory reestablishment of continuity. In the setting of a solitary kidney, these operative challenges may be further accentuated by the presence of deranged renal function pre-procedure and effect of prolonged pneumoperitoneum on renal function. In our cohort of patients, a transient rise in immediate post-operative renal profile was observed. This may be accounted by effects of prolonged pneumoperitoneum on solitary kidney and hypotensive anaesthetic protocol with limitation of intraoperative hydration in our patient cohort. During periodic revisits, there was stabilisation or progressive decline in renal parameters in most patients. In two patients, persistently elevated creatinine was recorded till last follow-up. They presented with high creatinine pre-procedure with long duration of symptoms and prior endoscopic corrections. Post-reconstruction, these patients had relief of symptoms and radiological follow-up revealed preservation of ureteral patency with unhindered drainage. This could be explained by irreversible renal parenchymal affection secondary to long standing distal obstruction and back pressure effects. Similar findings have been reported by other citations. [19] Similarly, non-resolution of hydronephrosis despite unobstructed drainage in follow-up imaging in two subjects could also be due to effects of long standing effects of obstruction on pelvicaliceal system. This reemphasizes the importance for early and satisfactory definitive reconstruction in these scenarios to ensure an optimal outcome.
Our study projects the short- and long-term outcomes following laparoscopic ureteral reconstructions in a solitary kidney. Most patients achieved a complete recovery of clinical, biochemical and radiological parameters. Despite diverse aetiologies and previous unsuccessful corrective procedures, satisfactory outcome was obtained consistently. The morbidity suffered by patients was also negligible. Operator experience with these cases is a crucial consideration. All our cases were undertaken by a single operator with vast experience in basic and advanced laparoscopy and familiar with similar reconstructions through both incisional and minimally invasive approaches. The outcome obtained at short-term post-procedure was maintained till last follow-up. This supports the durability of these reconstructions. The principal limitation of our study was a limited number of subjects and the retrospective study design. Larger multi-institutional studies and prospective comparison with alternative techniques of ureteral rehabilitation can further validate our results.