Endourological management of ureteric strictures after kidney transplantation: Stenting the stent
Endourological management of ureteric strictures after kidney transplantation: Stenting the stent
Bach, Christian; Kabir, Mohammed; Zaman, Faruquz; Kachrilas, Stefanos; Masood, Junaid; Junaid, Islam; Buchholz, Noor
2011-09-01 00:00:00
Arab Journal of Urology (2011) 9, 165–169 Arab Journal of Urology (Official Journal of the Arab Association of Urology) www.sciencedirect.com RENAL TRANSPLANTATION MINI-REVIEW Endourological management of ureteric strictures after kidney transplantation: Stenting the stent Christian Bach, Mohammed Kabir, Faruquz Zaman, Stefanos Kachrilas, Junaid Masood, Islam Junaid, Noor Buchholz Endourology and Stone Services, Department of Urology, Barts and the London NHS Trust, West Smithfield, London EC1A 7BE, UK Received 13 July 2011, Received in revised form 6 August 2011, Accepted 6 August 2011 KEYWORDS Abstract The incidence of ureteric obstruction after kidney transplantation is 3–12.4%, and the most common cause is ureteric stenosis. The standard treatment remains open surgical revision, but this is Ureteric stricture; associated with significant morbidity and potential complications. By contrast, endourological Kidney transplant; Stent; approaches such as balloon dilatation of the ureter, ureterotomy or long-term ureteric stenting are Metal; minimally invasive treatment alternatives. Here we discuss the available minimally invasive treatment Memokath options to treat transplant ureteric strictures, with an emphasis on long-term stenting. Using an exam- ple patient, we describe the use of a long-term new-generation ureteric metal stent to treat a transplant ureter where a mesh wire stent had been placed 5 years previously. The mesh wire stent was heavily encrusted throughout, overgrown by urothelium and impossible to remove. Because the patient had several previous surgeries, we first considered endourological solutions. After re-canalising the ureter and mesh wire stent by a minimally invasive procedure, we inserted a Memokath (PNN Med- ical, Kvistgaard, Denmark) through the embedded mesh wire stent. This illustrates a novel method for resolving the currently rare but existing problem of ureteric mesh wire stents becoming dysfunctional over time, and for treating complex transplant ureteric strictures. ª 2011 Arab Association of Urology. Production and hosting by Elsevier B.V. All rights reserved. Corresponding author. E-mail address: nb@londonurologyconsultant.com (N. Buchholz). 2090-598X ª 2011 Arab Association of Urology. Production and hosting by Elsevier B.V. All rights reserved. Production and hosting by Elsevier Peer review under responsibility of Arab Association of Urology. doi:10.1016/j.aju.2011.08.001 166 Bach et al. challenging under the distorted anatomical conditions after Introduction transplantation. To overcome these problems, self-expanding metallic mesh The incidence of ureteric obstruction after kidney transplanta- wire stents were used previously. They were first introduced for tion is 3–12.4% [1], and the most common cause is ureteric ste- treating biliary strictures and cardiovascular stenosis. For nosis. The standard treatment remains open revision and treating stenosis of the ureter, but also in the prostate and ure- ureteroneocystostomy or pyelo-ureterostomy [2], both invasive thra, they showed good short-term but disappointing long- approaches with significant morbidity and postoperative com- term results, with significant complications. There are only a plications. Also, it might be technically difficult in patients few reports of their use in transplant ureteric stenosis [18]. who have had many previous surgical interventions. By con- Their main disadvantage was the rapid urothelial overgrowth, trast, endourological approaches can offer minimally invasive with consecutive ingrowth of hyperplastic urothelium and treatment options [3]. Balloon dilatation of the ureter, ureter- granulation tissue. This frequently led to complete obstruction otomy or long-term ureteric stenting have all been used suc- and made removal of the device often impossible [4,5]. cessfully, albeit with each having its particular advantages Another more recent stenting option for ureters is the full- and disadvantages. length, double-pigtail, metallic Resonance ureteric stent For ureteric stenting, permanent mesh wire stents have been (Cook Medical, Bloomington, IN, USA). However, it must used previously, with varying success. The particular problem be exchanged at least once a year. For malignant extrinsic ure- with these stents is that they are overgrown by host tissue and teric obstruction the results have been encouraging, but for be- thus very difficult to remove later, if at all [4,5]. nign strictures they are still inconclusive [19]. Its use has not Here we discuss minimally invasive treatment options to yet been reported in ureteric stenosis of transplant kidneys. treat transplant ureteric strictures, with an emphasis on long- Nitinol metallic stents (Sinuflex, Optimed, Ettlingen, term stenting. Using the example of a patient we describe the Germany) have been successfully used in the treatment of use of a long-term new-generation ureteric metal stent to treat transplant ureteric stenosis, with a long-term patency of 75% a transplant ureter where a mesh wire stent had been placed after 4 years (16 patients) [20]. Another nitinol ureteric stent, 5 years previously. The mesh wire stent was heavily encrusted the Memokath 051, is a thermo-expandable, nickel-titanium throughout, overgrown by urothelium and impossible to re- alloy ureteric stent. With its spiral structure, the stent can move. Because the patient had undergone several previous sur- adapt to the curve of the ureter, avoiding outward pressure, gical procedures we first considered endourological solutions. thus preventing ischaemic lesions and preserving peristalsis. After re-canalising the ureter and mesh wire stent by a mini- The tight coils prevent urothelial ingrowth, which facilitates mally invasive procedure we inserted a Memokath 051 easy removal if needed, and its titanium component makes it (PNN Medical, Kvistgaard, Denmark) through the embedded resistant to encrustation and corrosion. Several studies have mesh wire stent. This illustrates a novel method of dealing with shown that the Memokath 051 not only has a successful the currently rare but existing problem of ureteric mesh wire long-term clinical outcome, but also is a cost-effective mini- stents becoming dysfunctional over time, and not only in mally invasive management option for both benign and malig- transplanted ureters. nant ureteric strictures [21]. A small series of its use in transplanted kidneys was pub- Minimally invasive endourological treatment options lished in 2005 [22]. Of four stents, two remained patent during a follow-up of 21 months, one was infected and replaced after The least invasive endourological therapy for ureteric stric- 14 months, and one migrated after only 10 days in situ. tures after kidney transplantation is balloon dilatation. This In cases where patency of the transplanted ureter cannot can be done by the antegrade or retrograde route and is often be achieved but major reconstructive surgery (i.e., ileum accompanied by placing a temporary stent. The short-term interposition) is not an option, an extra-anatomical subcutane- success rates are 50–65%, but the long-term results are rather ous stent (Detour, Coloplast, Minneapolis, USA) can be a disappointing [6–8]. Treatment in the first 10 weeks after trans- minimally invasive option. This subcutaneous bypass graft is plantation can be successful, whereas it is not recommended based on a PTFE-silicone tube. The proximal end is placed thereafter [9]. into the transplant kidney like a nephrostomy, and the tube it- Slightly more invasive are incisive approaches such as self is tunnelled under the skin and sutured into the bladder, endoureterotomy which can be done with electrocautery, laser acting as an artificial ureter. In a small series of eight patients, or the Acucise cutting balloon catheter (Applied Medical Re- seven showed good graft function with no evidence of obstruc- sources Corp., Laguna Hills, CA, USA). All have been used tion or infection. Recurrent infection occurred in two recipi- successfully, but to date the evidence is not convincing as ents, leading to one graft loss [23]. However, the Detour too few cases are reported [10–14]. stent remains a salvage procedure whenever other surgical or If such surgical treatment has failed or is impossible, for endourological approaches are not indicated or have failed example because the stricture is too long, long-term ureteric [24,25]. stenting remains as an option. JJ stents are perhaps the least invasive and most time-tested stents [15]. However, JJ stents The use of a metal stent in an unusual case are associated with complications such as irritative symptoms, encrustation, and, more importantly, infections, which occur A 27-year-old white man with a transplanted kidney and significantly more frequently in these immune-suppressed pa- prune-belly syndrome presented with acute onset of left loin tients if the stent is indwelling for >30 days [16,17]. Also, JJ pain, nausea, vomiting and fever of 38 C. His medical history stents need to be exchanged at least every 3–6 months, which showed a complex urological background, with renal failure is most inconvenient for the patients and can be technically and subsequently a live-related kidney transplant at the age Endourological management of ureteric strictures after kidney transplantation: Stenting the stent 167 of 21 years. Six months later he developed a uretero-vesical anastomotic stricture of the transplanted ureter. To avoid fur- ther open surgery the stricture was treated by anterograde radiological insertion of a self-expanding mesh-stent. A year after that, an atonic bladder necessitated a vesicostomy (Boari flap). Because of ischaemic necrosis and retraction this needed to be replaced shortly thereafter with a modified ileal conduit vesicostomy (bowel to bladder). During this intervention, the previously placed Wallstent was found to have migrated about 2.5 cm into the urinary bladder, and heavy urothelial over- growth made its repositioning or removal impossible. After trimming this overhanging part, the mesh-stent then remained patent for another 5.5 years, but recurrent UTIs necessitated several hospital admissions, with administration of intrave- nous antibiotics. On admission, physical examination revealed a tender left iliac fossa. Blood analysis results showed raised infection 9 1 parameters, with a white cell count of 17.2 · 10 L and a C-reactive protein level of 214 mg/L. Kidney function was impaired, with a GFR of 23 mL/min, a serum creatinine le- vel of 291 lmol/L and blood urea of 18.1 mmol/L. Two weeks earlier, on a routine check, the patient’s kidney func- tion had still been normal, with a GFR of 77 mL/min, a ser- um creatinine level of 104 lmol/L and blood urea of 8.6 mmol/L, respectively. Ultrasonography showed severe hydronephrosis of the transplanted kidney and a plain abdominal film showed pro- nounced calcifications adherent to the proximal end and lu- Figure 1 Encrusted mesh wire stent with a stone at the bladder men of the stent, as well as a stone of 15 · 10 mm at the end and encrustations in the lumen and the renal end in a distal end of the mesh stent that protruded into the bladder transplant ureter. (Fig. 1). As an initial emergency treatment the transplanted kidney was drained with a percutaneous nephrostomy, and under blood urea to 7.2 mmol/L. A follow-up abdominal plain film antibiotic treatment the patient’s kidney function and inflam- showed the position of the Memokath 051 inside the mesh wire matory values quickly returned to normal, indicating good stent, with no signs of re-encrustation (Fig. 3). kidney function and recovery potential. When the situation had stabilized, the patient was taken to theatre for a combined antegrade percutaneous and retrograde transurethral proce- dure, while supine. Percutaneous access to the transplant kid- ney was gained through the previously placed nephrostomy tube. After dilatation of the tract and insertion of the nephro- scope, the stone on the upper end of the mesh stent, and the heavily encrusted lumen, were cleared by electrohydraulic intracorporeal lithotripsy. The stone attached to the bladder side of the mesh stent was removed transurethrally in the same fashion. The now freed stent (Fig. 2) was completely over- grown by urothelium, making its removal impossible. Therefore a 100-mm long single-expansion Memokath 051 ureteric stent was inserted, using a technique described previ- ously [26], and positioned across the stricture through the 60 mm long mesh stent. Its expandable upper end was placed in the renal pelvis with its distal end protruding 20 mm into the bladder. Recovery after surgery was unremarkable, with a good uri- nary output from the conduit. Ultrasonography showed persis- tent resolution of the hydronephrosis. The renal function remained normal, so that the patient could be discharged 2 days later after removing the nephrostomy tube. At the most recent follow-up consultation 27 months after this intervention, the patient was clinically well with no UTIs, and had normal re- nal function. The GFR had improved to 81 mL/min, the serum Figure 2 ‘‘Through and trough wire’’ in the now encrustations- creatinine level to 99 lmol/L (normal range <110 lmol/L) and free mesh wire stent following percutaneous nephroscopy. 168 Bach et al. complications like encrustation or epithelial in-growth, and is cost-effective in the long run compared with JJ stents, with their need for frequent exchange [21]. As mentioned above, mesh wire stents when used previ- ously became overgrown by ureteric tissue and were often impossible to remove when encrusted and blocked [4,5]. This particular problem in the patient’s transplanted and mesh- stented ureter was overcome by ‘stenting the stented ureter’. Of course, such an unusual approach without comparable published evidence demands a thorough follow-up. However, should re-encrustation of the Memokath occur, it can be rela- tively easily exchanged, in contrast to a mesh wire stent. There was initial concern about possible electrostatic interaction be- tween the two metal stents. We had extensive discussions with the engineering department of the manufacturer, and con- cluded that complications arising from such interactions would be extremely unlikely. References [1] Dinckan A, Tekin A, Turkyilmaz S, Kocak H, Gurkan A, Erdogan O, et al. Early and late urological complications corrected surgically following renal transplantation. Transpl Int 2007;20:702–7 [Epub 2007 May 19]. ´ ´ [2] Hetet JF, Rigaud J, Leveau E, Le Normand L, Glemain P, Bouchot O, et al. Therapeutic management of ureteric strictures in renal transplantation. Prog Urol 2005;15:472–9 [discussion 479-80]. [3] Buchholz N, El Howairis M, Bach C, Moraitis K, Masood J. Figure 3 Follow-up X-ray after 27 months showing the position From stone cutting to Hi-technology methods: the changing face of the Memokath 051 inside the mesh wire stent without any of stone surgery. Arab J Urol 2011;9(1):25–7. signs of re-encrustation. [4] Hekimoglu B, Men S, Pinar A, Ozmen E, Soylu SO, Conkbayir I, et al. Urothelial hyperplasia complicating use of metal stents in malignant ureteral obstruction. Eur Radiol 1996;6:675–6781. [5] Pollak JS, Rosenblatt MM, Egglin TK, Dickey KW, Glickman Discussion M. Treatment of ureteral obstructions with the Wallstent endo- prosthesis: preliminary results. J Vasc Interv Radiol 1995;6: Endourology offers minimally invasive treatment options with 417–25. fewer side-effects and less patient morbidity than with open [6] Bachar GN, Mor E, Bartal G, Atar E, Goldberg N, Belenky A. surgery [3]. This is particularly interesting in unfit patients at Percutaneous balloon dilatation for the treatment of early and high surgical risk, or where open revision is considered techni- late ureteral strictures after renal transplantation: long-term cally difficult or has previously failed. follow-up. Cardiovasc Intervent Radiol 2004;27:335–8. Ureteric balloon dilatation [9,13] and the Acucise cutting [7] Bromwich E, Coles S, Atchley J, Fairley I, Brown JL, Keoghane SR. A 4-year review of balloon dilation of ureteral strictures in balloon catheter [14] can be regarded as truly minimally inva- renal allografts. J Endourol 2000;20:1060–1. sive treatment options, but could not be used in the present [8] Juaneda B, Alcaraz A, Bujons A, Guirado L, Dı´az JM, Martı´ J, case as an overgrown mesh stent was in place within the et al. Endourological management is better in early-onset ureteric wall. The same is true for the slightly more invasive ureteral stenosis in kidney transplantation. Transplant Proc semi-rigid or flexible ureteroscopy for electro- or laser- 2005;37:3825–7. ureterotomy [10,11]. In general, these procedures can become [9] Rabenalt R, Winter C, Potthoff SA, Eisenberger CF, Grabitz K, very challenging through the extra-anatomical access to and Albers P, et al. Retrograde balloon dilatation > 10 weeks after the passage through the transplanted ureter. New develop- renal transplantation for transplant ureter stenosis – our experi- ments in flexible ureteroscopy have helped to make these ence and review of the literature. Arab J Urol 2011. [Epub ahead procedures more feasible [27]. of print]. Available from: http://www.ajuweb.com/article/ PIIS2090598X11000349/fulltext. Long-term ureteric stenting with conventional JJ stents can [10] Gdor Y, Gabr AH, Faerber GJ, Wolf Jr JS. Holmium:yttrium- be considered as the least invasive option [15]. However, apart aluminium-garnet laser endoureterotomy for the treatment of trans- from necessitating frequent stent changes with their own asso- plant kidney ureteral strictures. Transplantation 2008;85:1318–13121. ciated morbidity, it would have exposed our immune- [11] Bhayani SB, Landman J, Slotoroff C, Figenshau RS. Transplant suppressed patient to the risk of recurrent UTI, which could ureter stricture: Acucise endoureterotomy and balloon dilation potentially affect graft survival [16,17]. are effective. J Endourol 2003;17:19–22. In our department we are familiar with the thermo- [12] Seseke F, Heuser M, Zo¨ ller G, Plothe KD, Ringert RH. expandable, nickel-titanium alloy Memokath 051 stent. Its first Treatment of iatrogenic postoperative ureteral strictures with use was reported in 1996 [28], and its first use in transplanted Acucise endoureterotomy. Eur Urol 2002;42:370–5. kidneys was reported in 2005 [22]. This stent does not need to [13] Giessing M. Transplant ureter stricture following renal trans- plantation: surgical options. Transplant Proc 2011;43:383–6. be changed, has shown a good long-term success rate, with no Endourological management of ureteric strictures after kidney transplantation: Stenting the stent 169 [14] He Z, Li X, Chen L, Zeng G, Yuan J, Chen W, et al. Endoscopic [21] Staios D, Shergill I, Thwaini A, Junaid I, Buchholz NP. The incision for obstruction of vesico-ureteric anastomosis in trans- Memokath stent. Expert Rev Med Dev 2007;4:99–101. planted kidneys. BJU Int 2008;102:102–6. [22] Boyvat F, Aytekin C, Colak T, Firat A, Karakayali H, Haberal [15] Figueiredo AJ, Parada BA, Cunha MF, Mota AJ, Furtado AJ. M. Memokath metallic stent in the treatment of transplant kidney Ureteral complications: analysis of risk factors in 1000 renal ureter stenosis or occlusion. Cardiovasc Intervent Radiol transplants. Transplant Proc 2003;35:1087–8. 2005;28:326–30. [16] Tavakoli A, Surange RS, Pearson RC, Parrott NR, Augustine T, [23] Azhar RA, Hassanain M, Aljiffry M, Aldousari S, Cabrera T, Riad HN. Impact of stents on urological complications and Andonian S, et al. Successful salvage of kidney allografts health care expenditure in renal transplant recipients: results of a threatened by ureteral stricture using pyelovesical bypass. Am J prospective, randomized clinical trial. J Urol 2007;177:2260–4. Transplant 2010;10:1414–9. [17] Wilson CH, Bhatti AA, Rix DA, Manas DM. Routine intraop- [24] Andonian S, Zorn KC, Paraskevas S, Anidjar M. Artificial erative ureteric stenting for kidney transplant recipients. Cochrane ureters in renal transplantation. Urology 2005;66:1109. Database Syst Rev 2005;19(4):CD004925. [25] Giessing M, Schnorr D, Loening SA. Artificial ureteral replace- [18] Cantasdemir M, Kantarci F, Numan F, Mihmanli I, Kalender B. ment following kidney transplantation. Clin Transpl 2006;578–9. Renal transplant ureteral stenosis: treatment by self-expanding [26] Papatsoris AG, Buchholz N. A novel thermo-expandable ureteral metallic stent. Cardiovasc Intervent Radiol 2003;26:85–7 [Epub metal stent for the minimally invasive management of ureteral 2002 Dec 20]. strictures. J Endourol 2010;24:48791. [19] Liatsikos E, Kallidonis P, Kyriazis I, Constantinidis C, Hendlin [27] Papatsoris A, Kachrilas S, El Howairis M, Masood J, Buchholz JU, Stolzenburg JU, Karnabatidis D, Siablis D. Ureteral N. Novel technologies in flexible ureterorenoscopy. Arab J Urol obstruction: is the full metallic double-pigtail stent the way to 2011;9(1):41–6. go? Eur Urol 2010;57:480–6 [Epub 2009 Feb 10]. [28] Kulkarni RP, Bellamy EA. A new thermo-expandable shape- [20] Burgos FJ, Bueno G, Gonzalez R, Vazquez JJ, Diez-Nicola´ sV, memory nickel-titanium alloy stent for the management of Marcen R, et al. Endourologic implants to treat complex ureteral ureteric strictures. BJU Int 1999;83:755–9. stenosis after kidney transplantation. Transplant Proc 2009;41:2427–9.
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Endourological management of ureteric strictures after kidney transplantation: Stenting the stent
Endourological management of ureteric strictures after kidney transplantation: Stenting the stent
Abstract
AbstractThe incidence of ureteric obstruction after kidney transplantation is 3–12.4%, and the most common cause is ureteric stenosis. The standard treatment remains open surgical revision, but this is associated with significant morbidity and potential complications. By contrast, endourological approaches such as balloon dilatation of the ureter, ureterotomy or long-term ureteric stenting are minimally invasive treatment alternatives. Here we discuss the available minimally invasive...
Arab Journal of Urology (2011) 9, 165–169 Arab Journal of Urology (Official Journal of the Arab Association of Urology) www.sciencedirect.com RENAL TRANSPLANTATION MINI-REVIEW Endourological management of ureteric strictures after kidney transplantation: Stenting the stent Christian Bach, Mohammed Kabir, Faruquz Zaman, Stefanos Kachrilas, Junaid Masood, Islam Junaid, Noor Buchholz Endourology and Stone Services, Department of Urology, Barts and the London NHS Trust, West Smithfield, London EC1A 7BE, UK Received 13 July 2011, Received in revised form 6 August 2011, Accepted 6 August 2011 KEYWORDS Abstract The incidence of ureteric obstruction after kidney transplantation is 3–12.4%, and the most common cause is ureteric stenosis. The standard treatment remains open surgical revision, but this is Ureteric stricture; associated with significant morbidity and potential complications. By contrast, endourological Kidney transplant; Stent; approaches such as balloon dilatation of the ureter, ureterotomy or long-term ureteric stenting are Metal; minimally invasive treatment alternatives. Here we discuss the available minimally invasive treatment Memokath options to treat transplant ureteric strictures, with an emphasis on long-term stenting. Using an exam- ple patient, we describe the use of a long-term new-generation ureteric metal stent to treat a transplant ureter where a mesh wire stent had been placed 5 years previously. The mesh wire stent was heavily encrusted throughout, overgrown by urothelium and impossible to remove. Because the patient had several previous surgeries, we first considered endourological solutions. After re-canalising the ureter and mesh wire stent by a minimally invasive procedure, we inserted a Memokath (PNN Med- ical, Kvistgaard, Denmark) through the embedded mesh wire stent. This illustrates a novel method for resolving the currently rare but existing problem of ureteric mesh wire stents becoming dysfunctional over time, and for treating complex transplant ureteric strictures. ª 2011 Arab Association of Urology. Production and hosting by Elsevier B.V. All rights reserved. Corresponding author. E-mail address: nb@londonurologyconsultant.com (N. Buchholz). 2090-598X ª 2011 Arab Association of Urology. Production and hosting by Elsevier B.V. All rights reserved. Production and hosting by Elsevier Peer review under responsibility of Arab Association of Urology. doi:10.1016/j.aju.2011.08.001 166 Bach et al. challenging under the distorted anatomical conditions after Introduction transplantation. To overcome these problems, self-expanding metallic mesh The incidence of ureteric obstruction after kidney transplanta- wire stents were used previously. They were first introduced for tion is 3–12.4% [1], and the most common cause is ureteric ste- treating biliary strictures and cardiovascular stenosis. For nosis. The standard treatment remains open revision and treating stenosis of the ureter, but also in the prostate and ure- ureteroneocystostomy or pyelo-ureterostomy [2], both invasive thra, they showed good short-term but disappointing long- approaches with significant morbidity and postoperative com- term results, with significant complications. There are only a plications. Also, it might be technically difficult in patients few reports of their use in transplant ureteric stenosis [18]. who have had many previous surgical interventions. By con- Their main disadvantage was the rapid urothelial overgrowth, trast, endourological approaches can offer minimally invasive with consecutive ingrowth of hyperplastic urothelium and treatment options [3]. Balloon dilatation of the ureter, ureter- granulation tissue. This frequently led to complete obstruction otomy or long-term ureteric stenting have all been used suc- and made removal of the device often impossible [4,5]. cessfully, albeit with each having its particular advantages Another more recent stenting option for ureters is the full- and disadvantages. length, double-pigtail, metallic Resonance ureteric stent For ureteric stenting, permanent mesh wire stents have been (Cook Medical, Bloomington, IN, USA). However, it must used previously, with varying success. The particular problem be exchanged at least once a year. For malignant extrinsic ure- with these stents is that they are overgrown by host tissue and teric obstruction the results have been encouraging, but for be- thus very difficult to remove later, if at all [4,5]. nign strictures they are still inconclusive [19]. Its use has not Here we discuss minimally invasive treatment options to yet been reported in ureteric stenosis of transplant kidneys. treat transplant ureteric strictures, with an emphasis on long- Nitinol metallic stents (Sinuflex, Optimed, Ettlingen, term stenting. Using the example of a patient we describe the Germany) have been successfully used in the treatment of use of a long-term new-generation ureteric metal stent to treat transplant ureteric stenosis, with a long-term patency of 75% a transplant ureter where a mesh wire stent had been placed after 4 years (16 patients) [20]. Another nitinol ureteric stent, 5 years previously. The mesh wire stent was heavily encrusted the Memokath 051, is a thermo-expandable, nickel-titanium throughout, overgrown by urothelium and impossible to re- alloy ureteric stent. With its spiral structure, the stent can move. Because the patient had undergone several previous sur- adapt to the curve of the ureter, avoiding outward pressure, gical procedures we first considered endourological solutions. thus preventing ischaemic lesions and preserving peristalsis. After re-canalising the ureter and mesh wire stent by a mini- The tight coils prevent urothelial ingrowth, which facilitates mally invasive procedure we inserted a Memokath 051 easy removal if needed, and its titanium component makes it (PNN Medical, Kvistgaard, Denmark) through the embedded resistant to encrustation and corrosion. Several studies have mesh wire stent. This illustrates a novel method of dealing with shown that the Memokath 051 not only has a successful the currently rare but existing problem of ureteric mesh wire long-term clinical outcome, but also is a cost-effective mini- stents becoming dysfunctional over time, and not only in mally invasive management option for both benign and malig- transplanted ureters. nant ureteric strictures [21]. A small series of its use in transplanted kidneys was pub- Minimally invasive endourological treatment options lished in 2005 [22]. Of four stents, two remained patent during a follow-up of 21 months, one was infected and replaced after The least invasive endourological therapy for ureteric stric- 14 months, and one migrated after only 10 days in situ. tures after kidney transplantation is balloon dilatation. This In cases where patency of the transplanted ureter cannot can be done by the antegrade or retrograde route and is often be achieved but major reconstructive surgery (i.e., ileum accompanied by placing a temporary stent. The short-term interposition) is not an option, an extra-anatomical subcutane- success rates are 50–65%, but the long-term results are rather ous stent (Detour, Coloplast, Minneapolis, USA) can be a disappointing [6–8]. Treatment in the first 10 weeks after trans- minimally invasive option. This subcutaneous bypass graft is plantation can be successful, whereas it is not recommended based on a PTFE-silicone tube. The proximal end is placed thereafter [9]. into the transplant kidney like a nephrostomy, and the tube it- Slightly more invasive are incisive approaches such as self is tunnelled under the skin and sutured into the bladder, endoureterotomy which can be done with electrocautery, laser acting as an artificial ureter. In a small series of eight patients, or the Acucise cutting balloon catheter (Applied Medical Re- seven showed good graft function with no evidence of obstruc- sources Corp., Laguna Hills, CA, USA). All have been used tion or infection. Recurrent infection occurred in two recipi- successfully, but to date the evidence is not convincing as ents, leading to one graft loss [23]. However, the Detour too few cases are reported [10–14]. stent remains a salvage procedure whenever other surgical or If such surgical treatment has failed or is impossible, for endourological approaches are not indicated or have failed example because the stricture is too long, long-term ureteric [24,25]. stenting remains as an option. JJ stents are perhaps the least invasive and most time-tested stents [15]. However, JJ stents The use of a metal stent in an unusual case are associated with complications such as irritative symptoms, encrustation, and, more importantly, infections, which occur A 27-year-old white man with a transplanted kidney and significantly more frequently in these immune-suppressed pa- prune-belly syndrome presented with acute onset of left loin tients if the stent is indwelling for >30 days [16,17]. Also, JJ pain, nausea, vomiting and fever of 38 C. His medical history stents need to be exchanged at least every 3–6 months, which showed a complex urological background, with renal failure is most inconvenient for the patients and can be technically and subsequently a live-related kidney transplant at the age Endourological management of ureteric strictures after kidney transplantation: Stenting the stent 167 of 21 years. Six months later he developed a uretero-vesical anastomotic stricture of the transplanted ureter. To avoid fur- ther open surgery the stricture was treated by anterograde radiological insertion of a self-expanding mesh-stent. A year after that, an atonic bladder necessitated a vesicostomy (Boari flap). Because of ischaemic necrosis and retraction this needed to be replaced shortly thereafter with a modified ileal conduit vesicostomy (bowel to bladder). During this intervention, the previously placed Wallstent was found to have migrated about 2.5 cm into the urinary bladder, and heavy urothelial over- growth made its repositioning or removal impossible. After trimming this overhanging part, the mesh-stent then remained patent for another 5.5 years, but recurrent UTIs necessitated several hospital admissions, with administration of intrave- nous antibiotics. On admission, physical examination revealed a tender left iliac fossa. Blood analysis results showed raised infection 9 1 parameters, with a white cell count of 17.2 · 10 L and a C-reactive protein level of 214 mg/L. Kidney function was impaired, with a GFR of 23 mL/min, a serum creatinine le- vel of 291 lmol/L and blood urea of 18.1 mmol/L. Two weeks earlier, on a routine check, the patient’s kidney func- tion had still been normal, with a GFR of 77 mL/min, a ser- um creatinine level of 104 lmol/L and blood urea of 8.6 mmol/L, respectively. Ultrasonography showed severe hydronephrosis of the transplanted kidney and a plain abdominal film showed pro- nounced calcifications adherent to the proximal end and lu- Figure 1 Encrusted mesh wire stent with a stone at the bladder men of the stent, as well as a stone of 15 · 10 mm at the end and encrustations in the lumen and the renal end in a distal end of the mesh stent that protruded into the bladder transplant ureter. (Fig. 1). As an initial emergency treatment the transplanted kidney was drained with a percutaneous nephrostomy, and under blood urea to 7.2 mmol/L. A follow-up abdominal plain film antibiotic treatment the patient’s kidney function and inflam- showed the position of the Memokath 051 inside the mesh wire matory values quickly returned to normal, indicating good stent, with no signs of re-encrustation (Fig. 3). kidney function and recovery potential. When the situation had stabilized, the patient was taken to theatre for a combined antegrade percutaneous and retrograde transurethral proce- dure, while supine. Percutaneous access to the transplant kid- ney was gained through the previously placed nephrostomy tube. After dilatation of the tract and insertion of the nephro- scope, the stone on the upper end of the mesh stent, and the heavily encrusted lumen, were cleared by electrohydraulic intracorporeal lithotripsy. The stone attached to the bladder side of the mesh stent was removed transurethrally in the same fashion. The now freed stent (Fig. 2) was completely over- grown by urothelium, making its removal impossible. Therefore a 100-mm long single-expansion Memokath 051 ureteric stent was inserted, using a technique described previ- ously [26], and positioned across the stricture through the 60 mm long mesh stent. Its expandable upper end was placed in the renal pelvis with its distal end protruding 20 mm into the bladder. Recovery after surgery was unremarkable, with a good uri- nary output from the conduit. Ultrasonography showed persis- tent resolution of the hydronephrosis. The renal function remained normal, so that the patient could be discharged 2 days later after removing the nephrostomy tube. At the most recent follow-up consultation 27 months after this intervention, the patient was clinically well with no UTIs, and had normal re- nal function. The GFR had improved to 81 mL/min, the serum Figure 2 ‘‘Through and trough wire’’ in the now encrustations- creatinine level to 99 lmol/L (normal range <110 lmol/L) and free mesh wire stent following percutaneous nephroscopy. 168 Bach et al. complications like encrustation or epithelial in-growth, and is cost-effective in the long run compared with JJ stents, with their need for frequent exchange [21]. As mentioned above, mesh wire stents when used previ- ously became overgrown by ureteric tissue and were often impossible to remove when encrusted and blocked [4,5]. This particular problem in the patient’s transplanted and mesh- stented ureter was overcome by ‘stenting the stented ureter’. Of course, such an unusual approach without comparable published evidence demands a thorough follow-up. However, should re-encrustation of the Memokath occur, it can be rela- tively easily exchanged, in contrast to a mesh wire stent. There was initial concern about possible electrostatic interaction be- tween the two metal stents. We had extensive discussions with the engineering department of the manufacturer, and con- cluded that complications arising from such interactions would be extremely unlikely. References [1] Dinckan A, Tekin A, Turkyilmaz S, Kocak H, Gurkan A, Erdogan O, et al. Early and late urological complications corrected surgically following renal transplantation. Transpl Int 2007;20:702–7 [Epub 2007 May 19]. ´ ´ [2] Hetet JF, Rigaud J, Leveau E, Le Normand L, Glemain P, Bouchot O, et al. Therapeutic management of ureteric strictures in renal transplantation. Prog Urol 2005;15:472–9 [discussion 479-80]. [3] Buchholz N, El Howairis M, Bach C, Moraitis K, Masood J. Figure 3 Follow-up X-ray after 27 months showing the position From stone cutting to Hi-technology methods: the changing face of the Memokath 051 inside the mesh wire stent without any of stone surgery. Arab J Urol 2011;9(1):25–7. signs of re-encrustation. [4] Hekimoglu B, Men S, Pinar A, Ozmen E, Soylu SO, Conkbayir I, et al. Urothelial hyperplasia complicating use of metal stents in malignant ureteral obstruction. Eur Radiol 1996;6:675–6781. [5] Pollak JS, Rosenblatt MM, Egglin TK, Dickey KW, Glickman Discussion M. Treatment of ureteral obstructions with the Wallstent endo- prosthesis: preliminary results. J Vasc Interv Radiol 1995;6: Endourology offers minimally invasive treatment options with 417–25. fewer side-effects and less patient morbidity than with open [6] Bachar GN, Mor E, Bartal G, Atar E, Goldberg N, Belenky A. surgery [3]. This is particularly interesting in unfit patients at Percutaneous balloon dilatation for the treatment of early and high surgical risk, or where open revision is considered techni- late ureteral strictures after renal transplantation: long-term cally difficult or has previously failed. follow-up. Cardiovasc Intervent Radiol 2004;27:335–8. Ureteric balloon dilatation [9,13] and the Acucise cutting [7] Bromwich E, Coles S, Atchley J, Fairley I, Brown JL, Keoghane SR. A 4-year review of balloon dilation of ureteral strictures in balloon catheter [14] can be regarded as truly minimally inva- renal allografts. J Endourol 2000;20:1060–1. sive treatment options, but could not be used in the present [8] Juaneda B, Alcaraz A, Bujons A, Guirado L, Dı´az JM, Martı´ J, case as an overgrown mesh stent was in place within the et al. Endourological management is better in early-onset ureteric wall. The same is true for the slightly more invasive ureteral stenosis in kidney transplantation. Transplant Proc semi-rigid or flexible ureteroscopy for electro- or laser- 2005;37:3825–7. ureterotomy [10,11]. In general, these procedures can become [9] Rabenalt R, Winter C, Potthoff SA, Eisenberger CF, Grabitz K, very challenging through the extra-anatomical access to and Albers P, et al. Retrograde balloon dilatation > 10 weeks after the passage through the transplanted ureter. New develop- renal transplantation for transplant ureter stenosis – our experi- ments in flexible ureteroscopy have helped to make these ence and review of the literature. Arab J Urol 2011. [Epub ahead procedures more feasible [27]. of print]. Available from: http://www.ajuweb.com/article/ PIIS2090598X11000349/fulltext. Long-term ureteric stenting with conventional JJ stents can [10] Gdor Y, Gabr AH, Faerber GJ, Wolf Jr JS. Holmium:yttrium- be considered as the least invasive option [15]. However, apart aluminium-garnet laser endoureterotomy for the treatment of trans- from necessitating frequent stent changes with their own asso- plant kidney ureteral strictures. Transplantation 2008;85:1318–13121. ciated morbidity, it would have exposed our immune- [11] Bhayani SB, Landman J, Slotoroff C, Figenshau RS. Transplant suppressed patient to the risk of recurrent UTI, which could ureter stricture: Acucise endoureterotomy and balloon dilation potentially affect graft survival [16,17]. are effective. J Endourol 2003;17:19–22. In our department we are familiar with the thermo- [12] Seseke F, Heuser M, Zo¨ ller G, Plothe KD, Ringert RH. expandable, nickel-titanium alloy Memokath 051 stent. Its first Treatment of iatrogenic postoperative ureteral strictures with use was reported in 1996 [28], and its first use in transplanted Acucise endoureterotomy. Eur Urol 2002;42:370–5. kidneys was reported in 2005 [22]. This stent does not need to [13] Giessing M. Transplant ureter stricture following renal trans- plantation: surgical options. Transplant Proc 2011;43:383–6. be changed, has shown a good long-term success rate, with no Endourological management of ureteric strictures after kidney transplantation: Stenting the stent 169 [14] He Z, Li X, Chen L, Zeng G, Yuan J, Chen W, et al. Endoscopic [21] Staios D, Shergill I, Thwaini A, Junaid I, Buchholz NP. The incision for obstruction of vesico-ureteric anastomosis in trans- Memokath stent. Expert Rev Med Dev 2007;4:99–101. planted kidneys. BJU Int 2008;102:102–6. [22] Boyvat F, Aytekin C, Colak T, Firat A, Karakayali H, Haberal [15] Figueiredo AJ, Parada BA, Cunha MF, Mota AJ, Furtado AJ. M. Memokath metallic stent in the treatment of transplant kidney Ureteral complications: analysis of risk factors in 1000 renal ureter stenosis or occlusion. Cardiovasc Intervent Radiol transplants. Transplant Proc 2003;35:1087–8. 2005;28:326–30. [16] Tavakoli A, Surange RS, Pearson RC, Parrott NR, Augustine T, [23] Azhar RA, Hassanain M, Aljiffry M, Aldousari S, Cabrera T, Riad HN. Impact of stents on urological complications and Andonian S, et al. Successful salvage of kidney allografts health care expenditure in renal transplant recipients: results of a threatened by ureteral stricture using pyelovesical bypass. Am J prospective, randomized clinical trial. J Urol 2007;177:2260–4. Transplant 2010;10:1414–9. [17] Wilson CH, Bhatti AA, Rix DA, Manas DM. Routine intraop- [24] Andonian S, Zorn KC, Paraskevas S, Anidjar M. Artificial erative ureteric stenting for kidney transplant recipients. Cochrane ureters in renal transplantation. Urology 2005;66:1109. Database Syst Rev 2005;19(4):CD004925. [25] Giessing M, Schnorr D, Loening SA. Artificial ureteral replace- [18] Cantasdemir M, Kantarci F, Numan F, Mihmanli I, Kalender B. ment following kidney transplantation. Clin Transpl 2006;578–9. Renal transplant ureteral stenosis: treatment by self-expanding [26] Papatsoris AG, Buchholz N. A novel thermo-expandable ureteral metallic stent. Cardiovasc Intervent Radiol 2003;26:85–7 [Epub metal stent for the minimally invasive management of ureteral 2002 Dec 20]. strictures. J Endourol 2010;24:48791. [19] Liatsikos E, Kallidonis P, Kyriazis I, Constantinidis C, Hendlin [27] Papatsoris A, Kachrilas S, El Howairis M, Masood J, Buchholz JU, Stolzenburg JU, Karnabatidis D, Siablis D. Ureteral N. Novel technologies in flexible ureterorenoscopy. Arab J Urol obstruction: is the full metallic double-pigtail stent the way to 2011;9(1):41–6. go? Eur Urol 2010;57:480–6 [Epub 2009 Feb 10]. [28] Kulkarni RP, Bellamy EA. A new thermo-expandable shape- [20] Burgos FJ, Bueno G, Gonzalez R, Vazquez JJ, Diez-Nicola´ sV, memory nickel-titanium alloy stent for the management of Marcen R, et al. Endourologic implants to treat complex ureteral ureteric strictures. BJU Int 1999;83:755–9. stenosis after kidney transplantation. Transplant Proc 2009;41:2427–9.
Early and late urological complications corrected surgically following renal transplantation
Therapeutic management of ureteric strictures in renal transplantation
From stone cutting to Hi-technology methods: the changing face of stone surgery
Urothelial hyperplasia complicating use of metal stents in malignant ureteral obstruction
Treatment of ureteral obstructions with the Wallstent endoprosthesis: preliminary results
Percutaneous balloon dilatation for the treatment of early and late ureteral strictures after renal transplantation: long-term follow-up
A 4-year review of balloon dilation of ureteral strictures in renal allografts
Endourological management is better in early-onset ureteral stenosis in kidney transplantation
Retrograde balloon dilatation > 10 weeks after renal transplantation for transplant ureter stenosis – our experience and review of the literature
Holmium:yttrium-aluminium-garnet laser endoureterotomy for the treatment of transplant kidney ureteral strictures
Transplant ureter stricture: Acucise endoureterotomy and balloon dilation are effective
Treatment of iatrogenic postoperative ureteral strictures with Acucise endoureterotomy
Transplant ureter stricture following renal transplantation: surgical options
Endoscopic incision for obstruction of vesico-ureteric anastomosis in transplanted kidneys
Ureteral complications: analysis of risk factors in 1000 renal transplants
Impact of stents on urological complications and health care expenditure in renal transplant recipients: results of a prospective, randomized clinical trial
Routine intraoperative ureteric stenting for kidney transplant recipients
Renal transplant ureteral stenosis: treatment by self-expanding metallic stent
Ureteral obstruction: is the full metallic double-pigtail stent the way to go?
Endourologic implants to treat complex ureteral stenosis after kidney transplantation
The Memokath stent
Memokath metallic stent in the treatment of transplant kidney ureter stenosis or occlusion
Successful salvage of kidney allografts threatened by ureteral stricture using pyelovesical bypass
Artificial ureters in renal transplantation
Artificial ureteral replacement following kidney transplantation
A novel thermo-expandable ureteral metal stent for the minimally invasive management of ureteral strictures
Novel technologies in flexible ureterorenoscopy
A new thermo-expandable shape-memory nickel-titanium alloy stent for the management of ureteric strictures
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