Laparoscopic Pyeloplasty in Adults: Stented Versus Stentless

Abstract

Introduction:

In this study, we aimed to investigate the efficacy and feasibility of stentless laparoscopic pyeloplasty (LP), compared with the stented counterpart.

Materials and Methods:

We compared the results of stented and stentless LP procedures performed at two centers. The indications included symptoms such as loin pain or urinary tract infection with documented obstruction on renal scintigraphy. Transperitoneal approach was standard for both techniques. The stented and stentless patient groups were compared with regard to surgical duration, length of hospital stay, postoperative symptomatology, complications, and radiologic and scintigraphic findings.

Results:

Twenty-seven patients with stentless pyeloplasty with at least 6 months of follow-up were included in the study and compared with a matched group of 21 stented LP patients. All had Anderson-Hynes dismembered pyeloplasty. Mean operative time was 151.9 minutes and 144.6 minutes in the stented and stentless groups, respectively (p > 0.05). Mean drain removal time and hospital stay were 1.9 days (range: 1–9 days) and 3.4 days (range: 2–9 days) in the stented group, respectively, and 2 days (range: 1–10 days) and 3.1 days (range: 1–10 days) in the stentless group, respectively (p > 0.05). Renal scintigraphy studies improved in 14 patients in the stented group and in 22 patients in the stentless group during the 6-month follow-up. Symptoms completely resolved in 19 of the stented and in 24 of the stentless cases.

Conclusion:

Stentless LP is a feasible technique as its stented counterpart. Although it has a relatively high prolonged leakage risk, it could be performed without compromising the success rate by experienced surgeons.

Introduction

U reteropelvic junction obstruction (UPJO) is a common congenital urologic anomaly that is commonly complicated by loin pain, urinary infection, renal deterioration, stone formation, and hypertension. Open Anderson-Hynes dismembered pyeloplasty remains the gold standard treatment of ureteropelvic obstruction,¹ although the previous century was witness to many competing techniques. Minimally invasive approaches are rapidly becoming the first-line treatment option. Improved skills of laparoscopic surgeons and use of robotic assistance have increased the surgical success rates and already made minimally invasive approaches the first-line therapy at most institutions.²

Use of internal stents during pyeloplasty is an urological dogma, which is thought to facilitate good drainage and be an effective guide for healing tissues by providing support and alignment. Nonetheless, the use of stents is not free of complications. As such, the use of stents has been questioned by many researchers, and in the era of open surgery, stentless pyeloplasty was reported to be safe in children.³ The present study aimed to present the success rate of stentless laparoscopic pyeloplasty (LP), compared with the stented counterpart.

Materials and Methods

We designed a multi-institutional study (two institutions) to assess and compare stented and stentless LP procedures performed by two surgeons who had completed at least 30 LPs each before initiation of the study. The study began in January 2008 after standardization of the stentless pyeloplasty technique by the two surgeons. All patients diagnosed with UPJO and who were candidates for LP joined the study after providing written informed consent. The kids (<17 years old) and the patients with atretic ureters and long stricture requiring extensive reconstruction were excluded.

The patients were evaluated with at least one radiologic imaging technique (computerized tomography or intravenous pyelography) and with dynamic scintigraphy (diethylene triamine pentaacetic acid [DTPA] or technetium 99m mercaptoacetyltriglycine [99mTc-MAG3]). The diagnosis of UPJO was done within a symptomatic patient who had radiologic and/or scintigraphic clues for obstruction. Borderline functioning or silent kidneys on DTPA were further evaluated with dimercaptosuccinic acid (DMSA) and/or percutaneous drainage if the renal unit have >5 mm parenchymal thickness. Surgical indications included symptoms such as loin pain or urinary tract infection with documented obstruction on renal scintigraphy, with or without renal deterioration. All the patients underwent routine physical examination, total blood count, serum biochemistry, and urine analysis and culture prior to surgery.

Stented pyeloplasty was the standard technique used by both surgeons and included the transperitoneal approach, mobilization of the colon, identification of the UPJ, spatulation of the ureter on its lateral side, antegrade placement of a Double-J stent, reduction pyeloplasty, and anastomosis using continuous/running technique. Renal stones on the related side were removed through one of the appropriate trocars during surgery using a flexible nephroscope.

The technique of stentless pyeloplasty included the following steps:

A transperitoneal approach using three trocars on the left side and four on the right side was the standard. The fourth trocar on the right side was used for liver retraction. In cases in which the UPJ could be reached and repaired without liver retraction, the forth trocar was not used. To assist suturing, a 3.5–5-mm trocar was used when needed.

The colon was mobilized medially to define the UPJ (Fig. 1A, B)

The ureter was spatulated without completely detaching it from the renal pelvis and a 6–8F feeding tube was inserted into the ureter (Fig. 1C, D)

The ureter was detached from the renal pelvis and the redundant pelvis was excised.

Ureteropelvic anastomosis began from the lower edge of the posterior wall over the crossing vessels (if present) using two running sutures and 16-mm needles (4.0 polyglactin) (Fig. 2A, B). After completion of ureteropelvic anastomosis, two stitches were tied and the renal pelvis was sutured to the upper edge of the renal pelvis where the feeding tube was squeezed. The feeding tube was removed from the abdomen through one of the trocars by leaving its distal tip in the renal pelvis. Then, the integrity of the anastomosis was confirmed by installation of physiologic serum through the feeding tube (Fig. 2C, D). If any leakage was observed, an additional suture was placed; if not, the feeding tube was removed and pelvic suturing was completed.

FIG. 1.

(A, B) The schematic and operative view of right-sided ureteropelvic obstruction, following mobilization of the ascending colon. (C, D) The schematic and operative view of a spatulated and cannulated ureter with an 8F feeding tube.

FIG. 2.

(A, B) Anastomosis began from the lower spatulated corner of the ureter anterior to the crossing vessels. (C, D) The feeding tube was retracted into the renal pelvis and the anastomosis was checked for leakage while installing physiologic serum from the extracorporeal end of the feeding tube.

A transperitoneal drain was routinely placed for both stented and stentless procedures, and an urethral catheter was inserted into the bladder. The urethral catheter was removed the following morning if there was no drainage. Patients were discharged after removal of the drain in the afternoon. If drainage was present, the urethral catheter was kept indwelling for an additional 48 hours. If urinary leakage continued for >48 hours, retrograde stenting was attempted first; percutaneous nephrostomy was reserved for patients in whom urinary leakage persisted after ureteral stenting. Internal stents were removed from all the patients at 6 weeks after pyeloplasty. Patients were scheduled for follow-up with intravenous pyelography at 3 months after surgery and DTPA/99mTc-MAG3 renograms at 6 months after surgery. The patients were asked to report any pain during the follow-up period and the occurrence of pain was recorded. Success was considered as an improvement in hydronephrosis and a nonobstructed diuretic renal scan with improved or stable split renal function. Failure was defined as radiologic and scintigrapic results showing deterioration conditions such as more hydronephrosis, deterioration of split renal function, or obstructed kidney.

The stented and stentless patient groups were compared with regard to surgical duration, length of hospital stay, postoperative symptomatology, complications, and radiologic and scintigraphic findings. Student's t-test was used for normally distributed data, the Mann-Whitney U test was used for continuous variables that deviated from normality, and the chi-square test was used to compare proportions with p < 0.05 considered statistically significant. All statistical data were processed using commercially available software.

Results

From January 2008 to March 2010, 37 consecutive patients with UPJO underwent implantation via stentless LP; 27of them with at least 6 months of follow-up were included in the study. A matched group of 21 stented LP patients was selected for comparative analysis. The patients' demographic data are summarized in Table 1.

Table 1.

Patient Demographic and Surgical Data

	Stented	Stentless	p-Value
No. of patients	21	27
Mean age in years (range)	31.8 (17–61)	32.6 (17–70)	0.843
Sex M/F	8/13	15/12	0.259
Side R/L	8/13	16/11	0.244
Symptom
Pain	21	25
Hypertension	3	4
Urinary tract infection	0	1
Hematuria	1	0
Frequency	0	1
Incidental	0	1
Previous surgery for UPJ	0	0
No. of crossing vessels (%)	11 (52.4%)	9 (33%)	0.117
Operative technique
Anderson-Hynes	21	27
Foley Y-V	0	0
Surgical duration (minutes)	151.9 (90–260)	144.6 (80–330)	0.598
Open conversion	0	0
Complications
Intraoperative	0	1	0
Postoperative	1	4	0.369
Urinary tract infection	0	0
Port site infection	0	1
Prolonged drainage	1	3
Hospital stay in days (range)	3.4 (2–9)	3.1 (1–10)	0.4
Drain removal time in days (range)	1.9 (1–8)	2 (1–10)	0.7
Follow-up in months (range)	22 (6–36)	11 (6–16)	0.000

UPJ = ureteropelvic junction.

Patient age ranged from 17 to 70 years and the most common symptom was pain on the related side in both groups. None of the patients had a history of previous surgery for the related kidney. Mean split renal function in the obstructed kidney was 37.6% (range: 5%–56%) in the stented group and 41% (range: 8%–56%) in the stentless group.

All the patients underwent Anderson-Hynes dismembered pyeloplasty. Crossing vessels were observed in 52.4% of stented cases and in 33% of the stentless pyeloplasty cases. Concomitant stone extraction was performed in five patients (two in the stented group and three in the stentless group). The only reported perioperative complication was bleeding from the vena cava, which was stopped with gauze compression. None of the patients in either group were converted to open surgery.

Mean operative time was 151.9 and 144.6 minutes in the stented and stentless groups, respectively (p > 0.05). Mean drain removal time and hospital stay were 1.9 days (range: 1–9 days) and 3.4 days (range: 2–9 days) in the stented group, respectively, and 2 days (range: 1–10 days) and 3.1 days (range: 1–10 days) in the stentless group, respectively (p > 0.05).

The most common postoperative complication was prolonged urinary drainage, which was observed in three cases (11.1%) in the stentless group and in one case (4.7%) in the stented group. Among the three patients in the stentless group, two were successfully treated with placement of Double-J stents and the third resolved spontaneously. The patient in the stented group was successfully treated with percutaneous nephrostomy. The stented patient with prolonged drainage had residual stone fragments, which was thought to be responsible for obstruction of the internal stent. This patient had recurrent flank pain and hematuria attacks related to stone passage during the follow-up. In the stentless group, blood clots were thought to be responsible for prolonged drainage, as retained blood coming from the internal stent was observed during stent placement.

Mean follow-up was 22.2 months (range: 6–36 months) in the stented group and 10.9 months (range: 6–16 months) in the stentless group. The split function values during the 6-month follow-up renal scans after LP did not differ significantly from the preoperative values (Table 2); however, improved renal function and clearance was noted in 14 patients (66.%) in the stented group and in 22 patients (81.5%) in the stentless group. The remainder of the patients were stable and without any compromise. Radiologic improvement was observed in 17 (80.9%) of the stented cases and in 22 (81.5%) of the stentless patients. The remainder of the patients were stable and did not deteriorate. Although pain improved in one of the stented and two of the stentless patients, it did not in one case in each group. Symptoms completely resolved in 19 (90.4%) of the stented and in 24 (88.8%) of the stentless cases.

Table 2.

Patient Follow-Up Summary

	Stented	Stentless	p-Value
Symptomatology			0.4
Complete resolution	19	24
Improvement	1	2
No change	1	1
Diuretic renography
(differential renal function%)
Preoperative	37.6 (5–56)	41 (8–56)	0.459
Postoperative	40 (16–54)	43.8 (21–66)	0.388
(Obstruction Pattern)			0.319
Improved	14	22
No change	7	5
Deteriorated	0	0
Radiologic Investigation			1
Improved	17	22
No change	4	5
Deteriorated	0	0

Discussion

The management of UPJO has changed dramatically along with the evolution of surgical therapies. Based on long-term results from recent studies, LP is replacing open and endoscopic interventions in the treatment algorithm. Many urologists think that in experienced hands, laparoscopic dismembered pyeloplasty should be considered the standard of care for routine cases of UPJO; however, the technical difficulty of and the high proficiency required for intracorporeal suturing remains a significant disadvantage of laparoscopy pyeloplasty. Experience is the sole factor that makes the results of LP comparable with those of open pyeloplasty.

Ureteral stenting has many indications in urologic practice and is commonly used during pyeloplasty; however, there are potential complications, including infection, pain on voiding, stent migration, and forgotten stents.⁴ In addition, stents may cause lower urinary tract symptoms and sexual dysfunction.⁵ Anticholinergic medications or early stent removal may be required to treat these local reactions.⁶ Moreover, the need for secondary general anesthesia in children has led to many urologic surgeons opting for stentless procedures.⁷

Stentless laparoscopic procedures require a watertight anastomosis, which calls for additional suturing experience via practice. The first five stentless LP cases were reported by Shalhav et al.⁶ They reported that the stentless technique was efficacious in a small cohort of five patients with limited follow-up and concluded that a larger cohort with longer follow-up was required. In the present comparative study, we observed that the stentless procedure was as effective as the stented procedure. Although the stentless procedure did not decrease surgical duration, it was safe and not associated with the risk of stent syndrome and additional cystoscopy for stent removal was not necessary.

From the technical viewpoint, stentless procedures eliminate the debate over placing stents in an antegrade or retrograde fashion, both of which are associated with advantages and disadvantages. Without retrograde stenting, patients are directly placed in the position for a laparoscopic approach without cystoscopy, and the renal pelvis remains dilated, which aids dissection. Without antegrade stenting, additional time could still be saved by surgeons inexperienced with certain tricks of antegrade stenting. Placing an appropriate feeding tube into the ureter helps with anastomosis of the lower spatulated corner, without interfering with suture placement, and facilitates a wide-corner anastomosis. Further, it helps in monitoring for a watertight anastomosis.

The continuous/running anastomosis was the preferred technique by both surgeons in order to achieve a watertight closure of the system. Although interrupted suture technique is widely used by most urologists, it has been reported as an important tip for reducing the time and simplifying the procedure.⁸

Laparoscopy could be beneficial for accompanying pathologies, such as stone disease, as it addresses both the intrinsic and extrinsic causes of obstruction similarly to open surgery. It has been proven to be efficacious in cases of crossing vessels, a large redundant renal pelvis, and failed endopyelotomy. According to Rehman et al,⁹ LP is advantageous because it facilitates easy identification of anterior crossing vessels that may be missed because of the limited view of the anterior surface of the UPJ during open pyeloplasty. Such crossing vessels are not uncommon and were observed in nearly 50% of the cases in the present study; all were saved and UPJ anastomosis was successfully performed anterior to these vascular structures. Similarly, when renal calculi are present, pyelolithotomy may be performed concurrently with LP.¹⁰ Five of the cases in the present study had accompanying renal stones, all of which were removed with a flexible nephroscope. Stone fragmentation with holmium laser was performed in only one case. All of the patients were rendered stone free, which was confirmed with early postoperative abdominal X-ray studies. Although small stone fragments were accepted as clinically insignificant, one patient with residual stones after laser lithotripsy had stent obstruction and prolonged drainage.

Intraoperative and postoperative complications of LP have been reported with a rate as high as 11.5%–12.7%.¹¹ The most common intraoperative complications are bowel injury and bleeding. These can often be managed laparoscopically or conservatively, although in certain circumstances open conversion is required. In the presented series, one patient had bleeding from the vena cava, which was controlled with simple compression. There were no other perioperative complications that resulted in additional procedures or open conversion. Postoperative urinary leakage was observed in both the stented and stentless groups, which were successfully managed with percutaneous nephrostomy and internal stenting. Blood clots in the stentless cases and stone fragments in the stented case were thought to be the cause of obstructed urine flow.

The present study has two limitations. Mean follow-up in the stentless group was relatively short; however, as most failures occur within 6 months of surgery, mean follow-up in the stentless group of almost 1 year is still acceptable.¹² In addition, the retrospective nature of the stented group did not permit us to address the complications of ureteral stent placement. Despite these limitations, the present study is the largest to compare the results of stented and stentless LP procedures, and stentless LP had a similar success rate as that of its stented counterpart (81%–99%).²

Conclusion

Stentless LP is considered as feasible as its stented counterpart in selected patients by experienced surgeons. The described technique and the presented results suggest that it is reproducible with acceptable success and low complication rates. However, it still has an increased risk of prolonged drainage.

Footnotes

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

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