Psoas hitch procedure in 166 adult patients: The largest cohort study before the laparoscopic era

Abstract Objectives To present the short‐term and long‐term outcomes of the psoas hitch procedure in a large cohort with long‐term follow‐up. Patients and methods A multicenter, retrospective cohort study was conducted. Patients were included if they had undergone an open psoas hitch procedure with ureteral reimplantation for different types of distal ureteral pathology between 1993 and 2017. Clinical failure was defined as radiologically‐proven obstruction of the ureteroneocystostomy and/or post‐operative complaints requiring additional surgery. Pre‐operative demographic data and post‐operative radiological imaging were collected. Complications were categorized as peri‐operative, acute (<30 days), and long‐term complications. Results A total of 166 patients had undergone a psoas hitch procedure, with a median follow‐up of 15 months (IQR 6‐45). Indications for the procedure included intra‐operative injury of the ureter during gynecological, urological or general surgery, transitional cell carcinoma of the distal ureter, fistulae, (radiation) fibrosis, and trauma. There was no significant difference in pre‐ and post‐operative estimated glomerular filtration rate. Post‐operative complications included urinary leakage, recurrent urinary tract symptoms, recurrent malignancy, and kidney failure. Postoperative imaging was available in 143 patients. Failure of the psoas hitch procedure was seen in 8% (11/143) of the patients. In 55% (6/11) of these patients, radiation fibrosis was the indication for the psoas hitch procedure. Conclusion This study provides greater insight into the long‐term complications of the open psoas hitch procedure in adults. The psoas hitch procedure can be considered a safe procedure for restoring the continuity of the ureter for different types of ureteral pathologies in adult patients. However, patients with a history of radiation therapy causing retroperitoneal fibrosis might be more prone to failure after the procedure.


| INTRODUC TI ON
The psoas hitch procedure is a surgical technique that was first described by Witzel in 1896. 1 Zimmerman et al. reported the first case series in 1960. 2 In 1968, the procedure was adjusted by Harrow, who added a subepithelial tunnel technique to prevent reflux, 3 and it was then named the "psoas hitch procedure" by Turner-Warwick and Worth. 4 Over the last few decades, the procedure has become a popular technique to bridge the distal third of the ureter.
The psoas hitch procedure has some benefits compared to other ureteral-bridging techniques. Alternative techniques to restore the continuity of the ureter are the Boari flap procedure, intestinal interposition, transureteroureterostomy, cutaneous ureterostomy, and autotransplantation of the kidney. 5 An advantage of the psoas hitch procedure is the use of native bladder instead of intestinal interposition, thus preserving urothelial continuity, an uncompromised blood supply, and preventing post-operative complications such as urinary tract infections, metabolic abnormalities, mucus, and stone formation.
Indications for the psoas hitch procedure are (iatrogenic) ureteral injury, 3 resection of a distal ureteral tumor, ureteric obstruction, and ureteral fistulae secondary to pelvic surgery or radiotherapy of the lower abdomen. Contraindications for the psoas hitch procedure are scarce. Severe hypertrophy of the bladder wall and previous extensive lower abdominal surgeries are tricky to proceed to this operation. Other relative contraindications are radiation of the lower abdomen, urethral strictures, neurogenic bladder, and bladder neck obstruction. 6 The psoas hitch procedure has been described in a few combined (children and adults) case series, the majority dating from 1969 to 1984. 5,[7][8][9][10][11][12][13][14][15][16][17] The psoas hitch procedure has shown to be an effective technique to restore ureterovesical continuity with success rates ranging from 72% to 96.7%, follow-up ranging from 17 months up to a mean follow-up of 4.5 years, and with minimal complications. 11,14,15 In 2011, we reported a smaller case series of 33 patients who had undergone a psoas hitch procedure in two large university medical centers in the Netherlands. Surgical success was seen in 93.9% (31/33) of the patients with a follow-up of 3-189 months. 18 The aim of the present study is to report long-term results, including the clinical failure of the psoas hitch procedure, in a large retrospective cohort of adult patients.

| Patients and methods
A multicenter, retrospective study was performed after obtaining approval from the Institutional Review Boards of the participating hospitals (reference number WAG/mb/17/024269). Informed consent was waived because of the retrospective review of records.
The records of 166 patients who underwent a psoas hitch procedure at the University Medical Center Utrecht and Erasmus University Medical Center from 1993 to 2017 were reviewed.

| Surgical technique
The surgical technique has previously been described by Turner-Warwick and Worth. 4 First, a Pfannenstiel or lower abdomen incision is made, then the ureter is identified and the extent of the ureteral pathology is assessed. Next, the psoas minor tendon must be identified above the level of the iliac vessels. The bladder is mobilized from the peritoneum with the division of the contralateral obliterated umbilical artery and, if necessary, bilateral division. The bladder is then opened, after being filled with 200-400 cc, transversely and laterally to the bladder dome and moved upwards to the affected ureter and hitched to the psoas minor tendon. Caution is warranted not to include the genitofemoral nerve. Ureteral reimplantation is preferably performed using a tunnel technique. A splint or double-J catheter is placed in the reimplanted ureter. Finally, the bladder is closed in an oblique-longitudinal fashion (Figures 1-2). Complications were categorized as peri-operative, acute (<30 days) and long-term complications (>30 days). Acute complications were retrospectively graded according to the Clavien-Dindo classification. 20 Long-term complications were classified as urinary incontinence, hydronephrosis, ureteral stricture, infections, and renal failure. If applicable, procedure-related re-interventions and mortality were reported. To assess the primary outcome, we included patients who were considered to provide sufficient data to radiologically assess clinical failure. In these patients, at least one type of postoperative imaging was available. The available post-operative imaging had mostly been indicated for follow-up of the underlying disease (i.e., CT-scan to assess gynecological tumor response). These postoperative imaging reports were considered valid to assess the radiological passage of the ureteroneocystostomy, as long as the condition of the kidneys and ureters were mentioned in the imaging reports.

| Outcome measures
We used a pragmatic approach and created a hierarchical order of certainty with which a post-operative imaging type can prove the radiological passage of a ureteroneocystostomy. The types of imaging were arranged in the following order: X-APG, renography, CT-IVU, CT-abdomen, and ultrasound.

| Statistical methods
Descriptives were used to display baseline and clinical characteristics, as well as complication rates.

| Post-operative results and complications
Mean post-operative renal function did not significantly differ from pre-operative renal function. The mean difference in serum creati-  CT-IVP, CT-abdomen, and ultrasound. Figure 3 shows the clinical failures, based on available post-operative imaging and clinical information. In at least 11 of the 143 patients (8%), the psoas hitch was considered a failure. Indications for their psoas hitch procedures were: radiation fibrosis (n = 6), fibrosis due to previous surgery (n = 1), iatrogenic damage during urologic surgery (n = 2), and iatrogenic damage during general surgery (n = 2), see Table 3. Seven of these patients were treated with a double-J catheter, PCN, or balloon dilatation to improve the passage of the reimplanted ureter. One of these patients showed no improvement in renal function after surgery and his PCN was never removed; this patient died shortly after surgery due to a malignant underlying disease.
Three patients were treated with secondary surgery; one patient underwent a Boari-flap procedure to restore continuity of the ureterovesical junction and in the other two patients an ileal conduit was created. A very small group of nine patients performed a micturition diary for 3 days. The mean functional capacity was 471 mL (250-810 mL).  with a history of pelvic irradiation should be made at the discretion of the urologist.

| D ISCUSS I ON
The psoas hitch procedure has so far been performed predomi- nantly with an open approach. However, case series ranging from 9 to 18 patients, [22][23][24][25][26][27][28][29] and one prospective cohort study of endometriosis patients (psoas hitch n = 94), 30 reported on the feasibility of laparoscopic and robot-assisted psoas hitch procedures with outcomes comparable to open surgery. For future research on psoas hitch procedures performed with a laparoscopic or robotic approach, our advice is to carry out effective follow-up and documentation of patients in whom a psoas hitch is performed, in order to be better able to assess the long-term results of the psoas hitch procedure.
To the best of our knowledge, this study describes the largest retrospective cohort of adult patients in the pre-laparoscopy era and provides greater insight into the long-term complications of the open psoas hitch procedure. In conclusion, the psoas hitch procedure is a relatively safe and effective procedure to restore the continuity of the ureter with preservation of kidney function in case of different types of ureteral pathologies. Since radiation fibrosis is the most common cause of clinical failure of the psoas hitch procedure, patients suffering from this etiology should be well counseled before the procedure. Conservative options, such as a permanent double-J catheter or PCN, might be appropriate alternatives.

CO N FLI C T O F I NTE R E S T
We declare no competing interests.