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REVIEW OF ENDOPYELOTOMY

AJIT M VAZE

Hon. Urologist and Andrologist, Jaslok Hospital, Sir HN Hospital, Lilavati Hospital and Research Centre, Mumbai.
HISTORY

Fridrich Trendelenburg 1886 1st recorded reconstructive procedure on UP junction, but unfortunately the patient’s death tampered "initial enthusiasm".

Ernest Custer 1891 - 1st successfully recorded reconstructive procedure. In 1901 Joachim Alberrans demonstrated splitting open of ureteric stricture, which he called ureteretome externe. This procedure remained dormant for next 35 years and in 1940, Davis from USA rediscovered Alberrans’ work. He ultimately reported a series of 18 patients who had 60% of objective success rate and 89% subjective success rate after end of six months. It was also discovered that the urethelium covered an open area within 5 days, muscle regeneration occurred in six weeks and peristalsis started within eight weeks. In 1988, Wickham 1st reported endoscopic lysis of UP junction which he called as pyelolysis. The success rate he reported was 64% after one year. This procedure was renamed in United States by Arthur Smith and Badlani, as endopyelotomy. By 1993 more than 190 cases with six years follow-up were presented and showed a success rate of 86%.

There were several variations which included antegrade and retrograde approach, use of balloon to intussuscept pelvis and than take incision or use acucise device. In 1987, Bakemen and Roth presented retrograde balloon dilatation as an alternative. Tolley, in 1986, emphasizes ureteroscopic retrograde endopyelotomy and in 1988 Thomas suggested use of double J stent one week prior to endopyelotomy. Today in United States, according to a recent survey performed by Gerber and Kim more than half of all adults with UPJO are treated with endopyelotomy antegrade percutaneous endoscopic incision, retrograde endoscopic incision, retrograde fluoroscopically guided balloon incision or balloon dilation burst.

INDICATIONS

Initially in the early 1990s the general indications for endopyelotomy included almost all forms of adult primary and secondary upjo provided that the length of obstruction was relatively short (i.e. 1 cm or less). During the last decade, several caveats have been added to stricture length, including grade IV hydronephrosis, poor function of the affected renal unit and presence of anterior crossing vessels. The least controversial of these have been grade III and IV hydronephrosis decreases to 50% to 60% according to work independently done by Van Cangh and Nesa and Danuser et al. Next, the impact of poor renal function on subsequent healing of the endopyelotomized ureteropelvic junction (UP) has been examined by several authors including Badlani et al,[1] Gupta and Smith[5], and Shalhav,[6] Kumar[7] and Danuser[8] et al. When the affected kidney functions in the 20% to 25% range, success for endopyelotomy decreases to the 70% range in most series, and when function drops below 20%, success falls to around 60%. The area of greatest controversy with regard to the indications for performing an endopyelotomy centers around the impact of anterior crossing vessels at the UPJ. In 1994 Van Cangh et al reported that the presence of a crossing vessel diagnosed at angiography decreased the success rate of endopyelotomy from 86% to 42%.[9] Subsequently, Nakada showed that the diagnosis of a crossing on vessels on spiral computed tomography (CT) was associated with a decline in successful outcome to 64% versus 92% when crossing vessels were not present.[10] A dissenting argument on this point has come from Gupta and Smith who, in a series of failed endopyelotomy cases treated with open surgery, cited that only 4% had a significant crossing vessel.[5] This finding is in marked contradiction to our recent experience with laparoscopic pyeloplasty in 36 patients with failed endopyelotomy or failed primary UPJ repair, of whom 87% were found to have a crossing vessel when spiral CT Angiography was obtained preoperatively. How do I counsel patients? If there is no crossing vessel, grade I-II hydronephrosis, renal function 25% or greater and a 1 cm or less obstruction, I recommend endopyelotomy knowing that it carries with it a 90+% success rate. On the other hand, for patients with upjo and grade IV hydronephrosis I recommend laparoscopic or open pyeloplasty with reduction of the redundant pelvis. Similarly, for patients with 10% or less renal function on the affected side, I recommend a laparoscopic simple nephrectomy. Also, for patients with strictures longer than 1 cm, I recommended open or laparoscopic repair. All other patients, approximately 50% of adults with UPJO, are in a "GREY" zone. As such, if there are anterior crossing vessels or renal function in the 11% to 25% range, I counsel patients that in my hands endopyelotomy will render a satisfactory result in no more than two-thirds. I offer these patients a choice between retrograde endoscopic/fluoroscopic endopyelotomy or laparoscopic pyeloplasty, which at our institution has over a 90+% success rate. About half of the patients elect endopyelotomy and for the other half we proceed with laparoscopic pyeloplasty.

TABLE 1
Endopyelotomy : Retrograde balloon and antegrade technique
Authors No. of Method of incision Stent size
(Fr)
StentDuration
(wk)
Overall Success Success Rate (%) Hospital stay
(days)
Average Follow-up
(range)
(mo)
Secondary Pyeloplasty
(%)
Secondary Nephrectom
(%)
  patients approach        
UPJ

UPJ
       
Balloon series                        
Beckman
et al 23
11 Antegrade
or retrograde
6 to 10 mm
balloon
8-10 4-8 73 86 50 - 10
(2-22)
- -
Webber et al 76 Retrograde 10 mm balloon 10 6-8 67 - - - (8-120) 3 11
Oakley et al267 20 Retrograde (15)
Antegrae (5)
10 mm balloon 6 6 67 72 33 4 22
(6-20)
- 15
Total 80   10 mm balloon 6-10 4-8 73 81 46 4.2 17 - -
Antegrade endopyelotomy
Van Cangh et al197 102 Antegrade Cold-cut knife 10-12 6 73 - - 6.7 60
(12-120)
11 0
Kletscher et al197 50 Antegrade Cold-cut knife 7-14 6 88 90 82 3-8 12
(4-74)
14 0
Brooks et al35 13 Antegrade Cold knife 7 or 14 4-6 77 - - 3 20
(4-53)
2 0
Korth et al201 286 Antegrade Cold knife Primestent
PCN/EP
3-6 73 80 67 - 20
(6-120)
- -
Gallucci and 46 Antegrade Cold knife 5 or 6 3 80 - - 4 - 4 -
Alpi100                   (12-60)    
Khan et al189 220 Antegrade Cold knife 8-12
PCN/EP
6 86.7 - - 5.2 - 5 3
Danuser et al66 80 Antegrade Cold knife 8/14 or 7/12
PCN/EP
6 89 - - 6 26
(1.5-72)
11 1
Shalhav et al326 83 Antegrade Electrosurgical 7 or 7/14 4-6 83 89 77 4 32 - -
Total 880     5-7/14 3-6 81 86 75 4.7 28 - -

UPJ, ureteropelvic junction

TABLE 2
Retrograde endopyelotomy and open pyeloplasty
Authors No. of Method of incision Stent size
(Fr)
StentDuration
(wk)
Overall Success Success Rate (%) Hospital stay
(days)
Average Follow-up
(range)
(mo)
Secondary Pyeloplasty
(%)
Secondary Nephrectom
(%)
  patients approach        
UPJ

UPJ
       

Ureterscopic series
39 Retrograde Electrocautery and
8 mm balloon
7/14 6-8 90 - - 1.2 16
(7-37)
- 8
Thomas et al356
Tawfiek et al352 32 Retrograde Electrosurgical
Ho : YAG laser
6-7/14 6-10 87.5 87.5 87.5 - 18
(5.49)
3 16
Gerber and Kim
(107a)
22 Retrograde Electrosurgical or Ho : YAG laser+
7mm balloon
7-7/14 6-7 82 - - < 1 21
(4.61)
5 0
Total 93 - - 6-7/14 6-10 87 - - - 16 - -
Acucise 9 Retrograde Acucise 7 or 14 406 78 - - 0.2 24
(15-32)
2 -
Brooks et al35
Nadler et al258 28 Retrograde Acucise 7 or 7/14 4-6 81 78 100 1.6 33
(24-43)
4 4
Faeber et al90 32 Retrograde Acucise 7/14 6-8 87.5 - - 1.8 14
(3-28)
12.5 -
Preminger et al293 66 Retrograde Acucise 7-7/14 6 77 72 100 - 7.8
(1-17.9)

- -
Shalhav et al326 66 Retrograde Acucise 7 or 7/14 4-6 77 71 83 2.2 20 - -
Lechevallier et al220 36 Retrograde Acucise 9 4-12 75 74 77 3 24
(6-42)
11 -
Total 237     7-7/14 4-12 79 74 90 1.8 17 - -
Open Pyeloplasty 2,481 Open Open pyeloplasty - - 88 - - - 8-10 2 3
Scardino and
Scardino (313)
Brooks et al35 11 Open Open pyeloplasty - - 100 - - 7.3 26
(9-44)
- -
Total 2,492     - - 94 - - - - - -

UPJ, ureteropelvic junction.

RESULTS

Before embarking on a review of endopyelotomy results the reader is cautioned to take what follows with a "Grain of Salt". Only recently has "Success" begun to be defined more quantitatively using renal scans and pain analog scales. Previous results have been based on much less objective instruments such as excretary urography (IVP), ultrasonography and office visit interviews. Today, I believe that the "Successful" patient should have a normal half-time, stable or improved function of the operated kidney and a pain analog scale showing greater than 50% pain relief. Lack of any of these 3 factors in my practice results in the case being deemed "Not a Success". Indeed, I have seen one patient with a 100% pain relief on the analog pain scale who initially refused follow-up radiographic studies, However, once obtained, the renal scan showed a nonfunctioning kidney. Likewise, several patients with a normal renal scan may still complain of significant loin pain for undetermined reasons; nonetheless, these patients also are "Not a success" antegrade endoscopic endopyelotomy appears to have the overall highest success rate with a range of 75% to 80%. However, in none of these series has renal scan and analog pain scale data been used to judge the outcomes. Retrograde endoscopic endopyelotomy has a success rate ranging from 69% to 85%. In the series of tawfiek et al patients were carefully screened with endoluminal ultrasound before being treated, and those with unfavorable factors were referred for laparoscopic pyeloplasty. As such it is not surprising that the success rate for retrograde endopyelotom at Jefferson in the highest at 88%. This outcome is based on normal renal scan and being "Pain-Free" at time of an office visit. For cutting balloon endopyelotomy (i.e. acucise, applied urology, rancho santa margarita, California the overall success rate has been 76% to 81% based on renal scans and in one series on analog pain scales. Lastly, balloon dilation and rupture of the UPJ were in fashion for only a short while. Success rates judged by IVP and rarely renal scan along with office visit interviews varied from 42% to 83% and long-term followup revealed a higher rate of failure than endopyelotomy.

Fig.1 Fig.2
Fig. 1:Acusice Balloon device
Fig. 2: Catheter and assembly for endohuminal ultrasound
Fig.3
Fig.4
Fig. 3: endohuminalUS-showing presences of vessel
Fig. 4: Spiral CT showing vessel
Fig.5
Fig.6
Fig. 5: Actual endopyelotomy
Fig. 6: Typical obstruction before endopyelotomy
Fig.7
Fig. 7: Rehosude balloon acusice device, followed by Balloon dilatation

CONUNDRUMS

There are several questions with regard to endopyelotomy technique and practice that merit mentioning. What is the best way to cut the UPJ? It would appear that cold kinef, holium laser and electrosurgical incision provide relatively similar outcomes. How big a stent should be left in place? While davis said as large as possible, others have demurred. For primary UPJ 7 Fr and 14 Fr stents appear to provide equal results in my experience but recent article by Danuser et al suggested that a better success rate (94% vs 70%) is obtainable when a 27 Fr antegrade stent is placed across the incised UPJ. It has been reported that a larger stent provides a better success rate (75% for 6 Fr vs 100% for 14 Fr) for secondary UPJ obstruction how long should the stent be left in place? While the consensus is 4 to 6 weeks, the reality is that good results have been reported with stent removal as early as 1 or 3 weeks while others have recommended stenting for up to 8 to 12 weeks. In one week the urothelium has covered the incision site, while by 8 to 12 weeks the muscle layer has likely reconstituted. Unfortuntaley, neither stent size nor stent duration has been the object of a multi-institutional prospective randomized study. Presently, using a retrograde approach, I place a 7/10 Fr stent for primary upjo and a 7/14 Fr endopyelotomy stent for secondary upjo. My practice still is to remove stent at 4 to 6 weeks. Lastly, we come to the final Davis conundrum : "will result once good, later become bad?" Davis said "No" but the literature says "Maybe". Others have found a late (i.e. 1 to 5 years postoperatively) failure rate 1% to 13%.

Unsettled issues of Indications

1. Concomitant presence of renal calculi.

2.Children

3. Massive Hydronephrosis


4.
Crossing vessels

5. Elderly patients.

6. High ureteral insertion

7. Poor renal function


1. Szewcyst Stal 1992, suggested presence of stone may give transient oedema and hence stone and UP junction obstruction should be viewed with caution.

2. Padiatric endopyelotomy - Towbin et al reported in 1987, 100% successful outcome with follow up of 15 months. Kavoussi et al 1994 had 62% success rate in primary with 100% in secondary upjo after 1 1/2 year. Hospital stay of open Vs endopyelotomy was same (2.5 day vs 3.1 day), op. time was 200 min VS 132 min, cost $ 8474 for endopyelotomy vs $5931 open Pyeloplasty.

3. In aged population success rate was 88% in both primary/secondary UP junction obstruc tion. Average stay was 6.3 day Horgan et al 1993.

4. High insertion, no effect on out come Chow et al 1999.


5.Gupta 1997 - 84% studied poor functioning kidney and UP junction obstruction and reported 54% success rate even if the function was 25%.

6. Glinz et al in 1999 studied massive hydronephrosis and UP junction obstruction. They came to the conclusion that if the renal pelvis size was less than 60 cc in volume, the success rate was excellent. Van Caugh et al in 1994 reported 76% success rate for minimal and moderate hydronephrosis as compared to 60% in massive hydronephrosis.

7. Van Caugh et al in 1994 reported the single most prognostic factor for outcome, was presence of crossing vessel. The best way to diagnose today is either by endoluminal ultrasound or use of spiral CT Scan (Nakada 1998).


Unsettled technical issues

1. Method of incision

2. Size of the stent

3. Period of stent

1. The traditional way is use of cold knife which was popularised by Wickham. Hulber et al 1998 suggested Electrical Current, Chandhoke 1993 use of accusice balloon, Oflynn 1989 use of dilating balloon and Bagley et al 1998 suggested Ho-Yag laser for incision.

2. The standard size of stent is 7 x 14 Fr which was popularised by Moon in 1994. Various external and internal Double Pigtail Stents are relegated to history books, however Hinman in 1999 showed again a use of 8-10 Fr stent with almost 88% success rate.

3. There is a lot of controversy about the period of stent. Kumar in 1999 suggested 12 weeks, Korth in 1991 suggested three weeks and Karble et al showed one week vs three week the same results.

FATE OF FAILED PROCEDURE

This difficult problem is very well tackled by two groups in 1993 and 1994. Kavoussi et al in 1993 presented five cases of failure of endopyelotomy, four underwent Salvage open Pyeloplasty with excellent results, one patient underwent nephrectomy due to non functioning status. Motola and Smith in 1994 presented a large series of 15 cases, all of them underwent successful Salvage Pyeloplasty.

DISCUSSION

It works but we don’t know how it works or why it works. Similarly, we don’t know for certain what size stent to leave or how long to leave it. We are perpetually mired by the empiricism of our phase I/phase II reports, and have yet to seek the knowledge that would be available to us were phase III scientific trial. In the final analysis the recent words of EO wilson ring true : "Without the instruments and accumulated knowledge of science, humans are trapped in a cognitive prison".


REFERENCES

1.Badlani G, Eshghi M, Smith AD. Percutaneous surgery for ureteropelvic junction obstruction (endopyelotomy); technique and early results. J Urol 1986; 135 : 26.

2 Gerber GS, Kim JC. Ureteroscopic endopyelotomy in the treatment of patients with ureteropelvic junction obstruction urology. 2000; 55 : 198.

3. Van Cangh PJ, Nesa S. Endopyelotomy. Prognostic factors and patient selection. Urol Clin North Am 1998; 25 : 281

4.Danuser H, Hochreiter WW, Ackermann DK, et al. Influence of stent size on the success of antegrade endopyelotomy for primary ureteropelvic junction obstruction : results of two consecutive series. J Urol 2001; 166 : 902.

5.Gupta M, Smith AD. Crossing vessels at the ureteropelvic junction : Do they influence endopyelotomy outcome? J Endourol 1996; 10 : 183.

6.Shalhav AL, Giusti G, Elbahnasy AM, et al. Endopyelotomy for high insertion ureteropelvic junction obstruction jendourol. 1998; 12 : 127.

7. Kumar R, Kapoor R, Mandhani A, et al. Optimum duration of splinting after endopyelotomy. J Endourol 1999; 13 : 89.

8.Danuser H, Ackermann DK, Bohlen D, et al. Endopyelotomy for primary ureteropelvic junction obstruction : risk factors determine the success rate. J Urol 1998; 159 : 56.

9. Van Cangh PJ, Wilmart JHF, Opsomer RJ, et al. Long-term results and late recurrence after endoureteropyelotomy : critical analysis of prognostic factors. J Urol 1994; 151 : 934.

10. Nakada SY, Wolf JS Jr., Brink JA, et al. Retrospective analysis of the effect of crossing vessels on successful retrograde endopelotomy outcomes using spiral computerized tomography angiography. J Urol 1998; 159 : 62.

11. Tawfiek ER, Liu JB, Bagley DH. Ureteroscopic treatment of ureteropelvic junction obstruction. J Urol 1998; 160 : 1643.


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