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The appendix as ureteral substitute: A report of 10 cases
Journal of Pediatric Urology (2008) 4, 14e19
The appendix as ureteral substitute: A report of 10 cases Haitham Dagash a,*, Sudipta Sen b, Jacob Chacko b, Sampath Karl b, Dhruv Ghosh b, Pulak Parag c, A.E. MacKinnon a a
Department of Paediatric Urology, Sheffield Children’s Hospital, Western Bank, Sheffield S10 2TH, UK Christian Medical College and Hospital, Vellore, India c Ekta Institute of Child Health, Raipur, Chhattisgarh, India b
Received 27 February 2007; accepted 13 August 2007 Available online 25 October 2007
KEYWORDS Appendix; Ureter; Ureteral substitution
Abstract Background: Ureteric replacement in part or in total is rarely needed in children. We present our experience in using the appendix to replace the ureter. Methods: A retrospective case note review was carried out at Sheffield Children’s Hospital (UK), Ekta Institute of Child Health (Raipur, Chhattisgarh, India) and Christian Medical College Hospital (Vellore, India) of all cases of ureteric substitution using the appendix. Results: Ten patients were identified, operated in 2002e2007: seven males and three females with a median age of 2.5 years (range 2.5 months to 12 years). The reasons for ureteric replacement were traumatic ureteric avulsion (n Z 1), congenital ureteric stenosis (n Z 5), non-drainage following previous pyeloplasty for pelvi-ureteric junction obstruction (n Z 3) and ureteric stricture following reimplantation for vesico-ureteric reflux (n Z 1). The appendix was used in an anti-peristaltic manner in all cases, and in one case a transureteroureterostomy was performed. At a median follow up of 16 months (1e72 months), all the patients were well except one whose kidney function had deteriorated. Conclusions: Total or partial replacement of the ureter using the appendix, even in the first year of life, preserved renal function in nine cases. Ureteric continuity can be successfully restored in children using the appendix. ª 2007 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Introduction The first reported case in which the appendix was used as a ureteral substitute was documented as early as 1912 by * Corresponding author. Tel.: þ44 1142717515; fax: þ44 1142260543. E-mail address: [email protected] (H. Dagash).
Melnikoff [1]. There are several options available to a surgeon faced with ureteral disruption/loss. Commonly used techniques include ileal interposition, psoas hitch, Boari flap, transureteroureterstomy, renal autotransplantation in the right iliac fossa and even nephrectomy. The use of the appendix to restore ureteral continuity has not been widely reported. We present here our experience, from three paediatric urological units, in using the appendix to replace the ureter.
1477-5131/$30 ª 2007 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jpurol.2007.08.004
The appendix as ureteral substitute
Methods A retrospective case note review was carried out at Sheffield Children’s Hospital (UK), Ekta Institute of Child Health (Raipur, Chhattisgarh, India) and Christian Medical College Hospital (Vellore, India) of all cases of ureteric substitution using the appendix. Demographic data, underlying diagnosis, type of appendicular substitution performed and follow-up data were all analysed. A total of 10 patients were identified (Table 1). They were operated in the period 2002e2007. There were seven males and three females with a median age of 2.5 years (range 2.5 months to 12 years).
Case series Case 1 A male infant underwent a right-sided dismembered pyeloplasty at 1 month of age for antenatally diagnosed hydronephrosis. Urine failed to drain except via the nephrostomy. Following referral, re-exploration revealed a tenuous ureter and re-do pyeloplasty failed to drain, yet there remained 30% of renal function in the operated kidney. A retrograde study revealed a ureter of less than 1 cm in length; therefore a ureteric replacement was performed using the appendix. Six years later renal function remained at 31%.
Case 2 A 12-year-old girl developed right-sided abdominal swelling following minor loin trauma. CT scan revealed rupture of her right kidney and a large perinephric haematoma, which was managed conservatively. Serial ultrasound scans revealed slow resolution of the haematoma, but with a persisting urinoma that was drained percutaneously. DMSA scan indicated non-perfusion of the lower pole. Cystoureteroscopy confirmed ureteric avulsion. At laparotomy, a lower pole partial nephrectomy was performed and ureteric continuity established with interposition of the appendix. Two years later she was well and DMSA confirmed 18% of renal function in a normal looking renal remnant as seen on ultrasound.
Case 3 A 2-year-old male child with bilateral hydronephrosis due to bilateral PUJ obstruction initially underwent a left pyeloplasty. He re-presented at 4 years of age with increasing hydronephrosis of the right side. A right pyeloplasty was performed, which failed. A nephrostogram showed no flow of dye. The nephrostomy was retained for 3 months. DTPA renogram showed a differential function of 56% on the left and 44% on the right. At re-do surgery the upper and part of the middle third of the right ureter were found to be fibrosed and strictured. The lower ureter was of normal calibre. The entire right ureter was replaced by the appendix with the caecal end anastomosed to the dilated pelvis and the appendicular tip re-implanted to the
15 bladder. The appendix was myotomised prior to its use by splitting the sero-muscular layer. The postoperative nephrostogram shows good flow of dye from the pelvis past the appendicular graft into the bladder. There had been a reduction of the right hydronephrosis on US and the DTPA renogram showed improvement in drainage. At follow up of 44.6 months, the differential renal function was L Z 62% and R Z 38%.
Case 4 A 6-year-old male child presented with abdominal pain and was diagnosed as having right-sided congenital midureteric stenosis with gross hydroureteronephrosis on the right side, and a normal left kidney. Preoperatively an intravenous pyelogram showed gross hydronephrosis of the right side with dilatation of the upper ureter that was confirmed on ultrasound (which also revealed an abrupt cut off after the middle third of the ureter). A preoperative retrograde pyelogram revealed a mid-ureteric stenosis with function of L Z 39% and R Z 61%. Operatively stenosis of the ureter from the mid-ureteric level proceeding distally was found. The stenosed portion of the ureter was replaced using the myotomised appendix, anastomosing the caecal end to the dilated upper ureter and implanting the appendicular tip into the bladder. Postoperatively an IVP revealed a reduction in the right-sided hydronephrosis with flow from the pelvis past the upper ureter, through the appendix and into the bladder. A postoperative ultrasound showed no increase in the hydronephrosis while the DTPA renogram showed slow but improved drainage on the right side. The differential function was L Z 41%, R Z 59% at 7.6 months postoperatively. The child’s pain had been relieved.
Case 5 A 3-year-old female child was admitted with a history of recurrent UTI since birth. The child had global developmental delay. A preoperative ultrasound revealed a contracted right kidney with left hydronephrosis and a gross dilatation of the left upper ureter. Micturating cystourethrogram (MCUG) showed right-sided grade 4 VUR. DTPA renogram showed a dilated left renal pelvis, upper and middle ureter with functions of L Z 81% and R Z 19%. An intraoperative retrograde pyelogram showed a dilated upper third of the left ureter with stenosed middle and lower thirds. The stenosed parts of the ureters were excised. The right ureter was disconnected from the right renal pelvis and anastomosed to the dilated left ureter in an end-to-end manner, thus utilizing the right dilated ureter to provide drainage for the left kidney. The gap between the disconnected right renal pelvis and the right ureter was bridged with the appendix. The caecal end of the myotomised appendix was anastomosed to the right pelvis while the distal end was anastomosed in an end-to-side fashion to the dilated right ureter. Postoperative left nephrostogram showed patency of all anastomoses and drainage into the bladder. DTPA renogram showed normal drainage on the right side and slow drainage on the left side (L Z 33%, R Z 67%) at 34 months after the operation.
16
Table 1
Data for 10 cases of ureteric substitution using the appendix
Case no.
Age
Etiology
Previous Surgery
Preoperative imaging
Postoperative imaging
Follow up (months)
Complications
1
4 months
Nil
5 years
44.6
Nil
4
6 years
Congenital right mid-ureteric stenosis
Nil
Right hydroureteronephrosis; mid-ureteric stenosis; function 61%
7.6
Nil
5
3 years
Congenital left mid-ureteric stenosis
Nil
6
2 years
Stricture right ureter
7
1 year
Failed right pyeloplasty
8
4 months
Right ureteric stricture
9
2.5 months
10
8 years
Congenital right ureteric stenosis (horse-shoe kidney) Congenital left mid-ureteric stenosis
B/L ureteric re-implantation, right Anderson Hynes pyeloplasty, right loop ureterostomy B/L Anderson Hynes pyeloplasty, right nephrostomy Right Anderson Hynes pyeloplasty Nil
Left hydroureteronephrosis; mid-ureteric stenosis function 11%; right grade 4 VUR Right hydronephrosis; no drainage from pelvis; function 36%; B/L grade 1 VUR
Adequate drainage; function 33% Normal residual right kidney Adequate drainage; decreased hydronephrosis; function 38% Adequate drainage; decreased hydronephrosis; function 59% Adequate drainage; function 33%
24
3
Ureter length <1 cm; function 33%; no drainage from pelvis Right persistent urinoma; non-perfusion right lower pole Right hydronephrosis; no drainage from pelvis; function 44%
Nil
12 years
Right Anderson Hynes pyeloplasty 2 Nil
72
2
?Stenosis/stricture right ureter Traumatic right ureteric avulsion Stricture right ureter
B/L Anderson Hynes pyeloplasty
Left ureteric reimplantation
34
UTI (1 episode)
Adequate drainage
8
Nil
Right hydronephrosis; no drainage from pelvis; no tracer activity
Adequate drainage; function 12%
4.9
Nil
Right hydronephrosis; no drainage from pelvis Hydronephrosis and poor visualization (right moiety) Left hydroureteronephrosis; creatinine 4.7 mg/dl
Adequate drainage
1
Nil
60
Nil
1
Nil
Adequate drainage; decreased hydronephrosis Normal Whitaker test; creatinine 1.2 mg/dl
B/L, bilateral.
H. Dagash et al.
The appendix as ureteral substitute
Case 6 A 2-year-old male child was diagnosed at another centre with bilateral primary VUR. The child underwent bilateral ureteric re-implantation, following which he continued to have significant right-sided hydronephrosis, and a diagnosis of a right PUJ obstruction was made. This was treated by a pyeloplasty in the same hospital, following which the hydronephrosis persisted with recurrent infections. A rightsided high loop ureterostomy was then performed. Subsequently, he was referred to our institution. Preoperative MCUG revealed bilateral grade 1 VUR. A dye study through the ureterostomy revealed obstructed drainage from the pelvis into the ureter. Ultrasound showed gross hydronephrosis of the right kidney. DTPA renogram showed poor parenchymal uptake on the right side with poor clearance of the tracer, with functions L Z 64% and R Z 36%. Operatively a stricture of the upper third of the ureter was revealed. As there had been surgery on both the upper and lower ends of the ureter it was not considered prudent to interfere with the ureter. The myotomised appendix was used to bypass the strictured segment, with the caecal end anastomosed to the pelvis and the tip anastomosed to the dilated lower ureter over a double J stent with a nephrostomy. The ureterostomy was not closed at this point. Postoperatively the child was well with no recurrence of the UTI. A postoperative nephrostogram showed good drainage from the pelvis via the appendix into the lower ureter and further into the bladder. The child’s double J stent was removed and ureterostomy closed. At recent re-evaluation the right kidney function had deteriorated from 36% preoperatively to non-functioning.
Case 7 A 1-year-old male child was antenatally diagnosed to have bilateral PUJ obstruction and underwent a right pyeloplasty at 1 month of age. He re-presented with abdominal distension and a palpable mass on the right side. IVP and DTPA scan showed non-function of right kidney and left PUJ obstruction. The child underwent a left pyeloplasty and right nephrostomy which drained pus from the right kidney. Subsequent right nephrostogram showed no flow of the dye from the pelvis into the ureter. The child was again taken up for surgery and the entire right ureter was replaced by anastomosing the caecal end of the myotomised appendix to the pelvis and implanting the distal end to the bladder. The DTPA scan 5 months later showed tracer activity in the right renal bed with the differential function being 12% on the right and 88% on the left.
Case 8 A 4-month-old female child was diagnosed antenatally to have right PUJ obstruction. The child underwent a pyeloplasty at 2 months of age. At operation the ureteric calibre was narrow and did not admit a 3-Fr ureteric catheter. Following surgery there was no drainage from the right pelvis into the ureter. Nephrostomy drainage was continued but the pyeloplasty did not function (Fig. 1A). The myotomised appendix was used to replace the ureter by anastomosing
17 the caecal end to the pelvis and re-implanting the tip into the bladder. Postoperative nephrostogram showed good drainage of the dye from the pelvis, through the appendix into the bladder (Fig. 1B). On follow up 6 months later the right kidney showed 46% differential function.
Case 9 A 2.5-month-old male infant presented with a painless mass in the right half of the abdomen. Ultrasound revealed a horse-shoe kidney with hydronephrosis of the right moiety. The right ureter was not visualized. An IVP showed poor visualization of the right moiety. The left system was visualized normally. The right system was approached by a right infraumbilical incision. A very large right renal pelvis was found. The right ureter was aperistaltic and stenosed in its entire length, and did not admit a 3-Fr catheter. The isthmus of the horse-shoe was located at the level of aortic bifurcation. A single renal artery arose anteriorly from the aorta, just above the isthmus, and supplied the entire kidney. It gave branches first to the right system and finally ended supplying the left system (Fig. 2A). The appendix was used to replace the entire right ureter, in an antiperistaltic manner. A psoas hitch was also done on the right side (Fig. 2B). A 12-Fr Malecot’s catheter was left through the lower calyx as a nephrostomy. A 5-Fr trans-anastomotic tube was left passing into the bladder. A supra-pubic catheter was also left for bladder drainage. On the 14th day, the trans-anastomotic tube was removed and a nephrostogram was done under fluoroscopy (Fig. 3A). One year post surgery an ultrasonogram showed a significant decrease in the pelvi-calyceal dilatation (Fig. 3B). The patient remained well 5 years later.
Case 10 An 8-year-old boy presented with a very large solitary left hydronephrotic kidney with renal failure. Serum creatinine at presentation was 2.0 mg/dl. Ultrasound and MCUG revealed left hydroureteronephrosis with no reflux. Ureteric reimplantation was done with a presumptive diagnosis of obstructive megaureter. This failed to relieve the obstruction and he re-presented with a rise of serum creatinine to 4.7 mg/dl. A nephrostomy was placed and there was partial resolution of creatinine to 2.1 mg/dl. At re-exploration the left ureter was found to have multiple zones of severe stenosis with intervening areas of dilatation from the mid-ureter downwards. This unhealthy ureter was resected, and the gap between the dilated mid-ureter and bladder was bridged with the myotomised appendix. Though the follow up was short the serum creatinine has remained stable at 1.2 mg/ dl. Prior to removal of nephrostomy, a Whitaker test showed that the pressure difference between the kidney and bladder did not exceed 2 cm of H2O, demonstrating no obstruction to flow through the appendicular substitution of ureter.
Discussion Ureteral replacement in children is rarely needed, but when the situation does arise, the perfect substitute has
18
H. Dagash et al.
Figure 1 (A) Preoperative nephrostogram showing no drainage from the right renal pelvis. (B) Postoperative nephrostogram shows flow of dye from pelvis through ureter into bladder.
not yet been determined. The ileum has been used, as have the Fallopian tubes [2e4]. The appendix has been used as a conduit in continence vesicostomies (Mitrofanoff) [5] and also in biliary atresia [6]. A review of the literature revealed isolated reports on the use of the appendix as a ureteral substitute in children. In 1981, Martin used the appendix as a conduit from the pelvis of the right kidney to the left ureter in an 8-year-old boy with PUV and a right ureteric stricture [7]. Renal function was satisfactory 3.5 years later. Mesrobian and Azizkhan used the appendix to bridge the gap between right renal pelvis and left ureter in a 7-year-old girl with
dermatomyositis and ureteral necrosis [8]. An IVP after 3 months showed good renal function and she was clinically well at 6 months. Estevao-Costa used the appendix to bridge a 7-cm-long ureteral defect following trauma [9]. Two years postoperatively the differential renal function was 41% on the side of the replacement. The largest series in children to date was by Richter et al. [10]. They reported their results with three paediatric cases followed up at 4, 7 and 15 years. All patients had good renal function, and the authors concluded that these results support the use of the appendix as a right ureteral substitute in select cases.
Figure 2 Diagrammatic representation of pathology and surgery. (A) Horseshoe kidney with (a) atretic and aperistaltic right ureter and (b) a single renal artery. (B) The vermiform appendix has been interposed: (a) pelvis anastomosed with the base of the appendix, (b) psoas hitch and (c) tip of the appendix implanted into the bladder making a submucosal channel. (Nephrostomy and stent are not shown in this picture.)
The appendix as ureteral substitute
19
Figure 3 Postoperative imaging. (A) Nephrostogram done on 14th postoperative day showing dye going into the bladder through the appendix (arrow). (B) Ultrasonography done after 1 year showing the decompressed right pelvis and the patent conduit.
The appendix can be used as a conduit in ureteral substitution for a number of reasons. The appendix and ureter are similar in calibre [10]. The peristaltic properties of the appendix have been cited as an advantage over the use of Fallopian tubes [11]. Most reports do not define the orientation of the appendix, and in our series all were placed in an anti-peristaltic manner. Also, because of the small mucosal surface area, there is no relevant absorption of sodium chloride and urea; hence no electrolyte disturbances are seen, which is a potential problem when ileum is used. Disproportion between the ureter and appendix (ureteral calibre being much larger) may be overcome by including a caecal cuff, allowing a more secure anastomosis [8]. We employed a caecal cuff for anastomosis to the renal pelvis in all cases. A longitudinal myotomy was done in all the cases from Vellore after placing the graft in an antiperistaltic fashion, to avoid the ill effects of reverse peristalsis. There are also reported disadvantages to using the appendix. Potential problems are stenosis, fistula formation and anastomotic breakdown. The latter complication was found to be higher in iso-peristaltic interposition, especially at the superior anastomosis [12,13]. A review of the literature failed to reveal any cases of anastomotic breakdown when the appendix was interposed in an antiperistaltic manner. We agree with Estevao-Costa that antiperistaltic interposition is probably of no real functional significance, but it does theoretically reduce torsion of the mesoappendix and thus prevents any further vascular compromise [9]. Some authors advocate the use of mucolytic agents such as acetylcysteine for preventing mucinous obstruction [14]. This agent has been shown both in vitro and in vivo to relieve mucinous obstruction when a bowel segment was used for ureteral interposition [15,16]. Benderev encountered mucinous obstruction in an ileal segment interposition and successfully cleared it by instillation of acetylcysteine via a nephrostomy [16]. We have not encountered any cases of mucinous obstruction when using the appendix. In conclusion, we report nine cases where the appendix was used as right ureteral substitute and one where the left ureter was substituted, with good results in all but one
case, and conclude that this technique is feasible and safe, even in infants.
References [1] Melnikoff AE. Sur le replacement de l’uretere par anse isolee de l’intestine grele. Rev Clin Urol 1912;1:601e3. [2] Boxer RJ, Johnson SF, Ehrlich RM. Ureteral substitution. Urology 1978;12:269e78. [3] Boxer RJ, Fritzsche P, Skinner DG, Kaufman JJ, Belt E, Smith RB, et al. Replacement of the ureter by small intestine: clinical application and results of the ileal ureter in 89 patients. J Urol 1979;121:728e31. [4] Duncan RE, Evans AT. Fallopian tube as ureteral substitute in a living donor renal allograft. Br J Urol 1975;47:300. [5] Mitrofanoff P. [Trans-appendicular continent cystostomy in the management of the neurogenic bladder]. Chir Pediatr 1980;21:297e305. [6] Valla JS. Hepaticoportoappendicostomy. J Pediatr Surg 1988; 23:1057e8. [7] Martin LW. Use of the appendix to replace a ureter. Case report. J Pediatr Surg 1981;16:799e800. [8] Mesrobian HG, Azizkhan RG. Pyeloureterostomy with appendiceal interposition. J Urol 1989;142:1288e9. [9] Estevao-Costa J. Autotransplantation of the vermiform appendix for ureteral substitution. J Pediatr Surg 1999;34:1521e3. [10] Richter F, Stock JA, Hanna MK. The appendix as right ureteral substitute in children. J Urol 2000;163:1908e12. [11] Komatz Y, Itoh H. A case of ureteral injury repaired with appendix. J Urol 1990;144:132e3. [12] Lloyd SN, Kennedy C. Autotransplantation of the vermiform appendix following ureteroscopic damage to the right ureter. Br J Urol 1989;63:216e7. [13] Fernandez Fernandez A, Soria Ruiz S, Gomez Martinez I, Gil Fabra J, Martinez Castellan ˜os F, Otero Mauricio G. Blunt traumatic rupture of the high right ureter repaired with appendix interposition. Urol Int 1994;53:97e8. [14] Jang TL, Matschke HM, Rubenstein JN, Gonzalez CM. Pyeloureterostomy with interposition of the appendix. J Urol 2002; 168:2106e7. [15] Gillon G, Mundy AR. The dissolution of urinary mucus after cystoplasty. Br J Urol 1989;63:372e4. [16] Benderev TV. Acetylcysteine for urinary tract mucolysis. J Urol 1988;139:353e4.
The appendix as ureteral substitute: A report of 10 cases Haitham Dagash a,*, Sudipta Sen b, Jacob Chacko b, Sampath Karl b, Dhruv Ghosh b, Pulak Parag c, A.E. MacKinnon a a
Department of Paediatric Urology, Sheffield Children’s Hospital, Western Bank, Sheffield S10 2TH, UK Christian Medical College and Hospital, Vellore, India c Ekta Institute of Child Health, Raipur, Chhattisgarh, India b
Received 27 February 2007; accepted 13 August 2007 Available online 25 October 2007
KEYWORDS Appendix; Ureter; Ureteral substitution
Abstract Background: Ureteric replacement in part or in total is rarely needed in children. We present our experience in using the appendix to replace the ureter. Methods: A retrospective case note review was carried out at Sheffield Children’s Hospital (UK), Ekta Institute of Child Health (Raipur, Chhattisgarh, India) and Christian Medical College Hospital (Vellore, India) of all cases of ureteric substitution using the appendix. Results: Ten patients were identified, operated in 2002e2007: seven males and three females with a median age of 2.5 years (range 2.5 months to 12 years). The reasons for ureteric replacement were traumatic ureteric avulsion (n Z 1), congenital ureteric stenosis (n Z 5), non-drainage following previous pyeloplasty for pelvi-ureteric junction obstruction (n Z 3) and ureteric stricture following reimplantation for vesico-ureteric reflux (n Z 1). The appendix was used in an anti-peristaltic manner in all cases, and in one case a transureteroureterostomy was performed. At a median follow up of 16 months (1e72 months), all the patients were well except one whose kidney function had deteriorated. Conclusions: Total or partial replacement of the ureter using the appendix, even in the first year of life, preserved renal function in nine cases. Ureteric continuity can be successfully restored in children using the appendix. ª 2007 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Introduction The first reported case in which the appendix was used as a ureteral substitute was documented as early as 1912 by * Corresponding author. Tel.: þ44 1142717515; fax: þ44 1142260543. E-mail address: [email protected] (H. Dagash).
Melnikoff [1]. There are several options available to a surgeon faced with ureteral disruption/loss. Commonly used techniques include ileal interposition, psoas hitch, Boari flap, transureteroureterstomy, renal autotransplantation in the right iliac fossa and even nephrectomy. The use of the appendix to restore ureteral continuity has not been widely reported. We present here our experience, from three paediatric urological units, in using the appendix to replace the ureter.
1477-5131/$30 ª 2007 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jpurol.2007.08.004
The appendix as ureteral substitute
Methods A retrospective case note review was carried out at Sheffield Children’s Hospital (UK), Ekta Institute of Child Health (Raipur, Chhattisgarh, India) and Christian Medical College Hospital (Vellore, India) of all cases of ureteric substitution using the appendix. Demographic data, underlying diagnosis, type of appendicular substitution performed and follow-up data were all analysed. A total of 10 patients were identified (Table 1). They were operated in the period 2002e2007. There were seven males and three females with a median age of 2.5 years (range 2.5 months to 12 years).
Case series Case 1 A male infant underwent a right-sided dismembered pyeloplasty at 1 month of age for antenatally diagnosed hydronephrosis. Urine failed to drain except via the nephrostomy. Following referral, re-exploration revealed a tenuous ureter and re-do pyeloplasty failed to drain, yet there remained 30% of renal function in the operated kidney. A retrograde study revealed a ureter of less than 1 cm in length; therefore a ureteric replacement was performed using the appendix. Six years later renal function remained at 31%.
Case 2 A 12-year-old girl developed right-sided abdominal swelling following minor loin trauma. CT scan revealed rupture of her right kidney and a large perinephric haematoma, which was managed conservatively. Serial ultrasound scans revealed slow resolution of the haematoma, but with a persisting urinoma that was drained percutaneously. DMSA scan indicated non-perfusion of the lower pole. Cystoureteroscopy confirmed ureteric avulsion. At laparotomy, a lower pole partial nephrectomy was performed and ureteric continuity established with interposition of the appendix. Two years later she was well and DMSA confirmed 18% of renal function in a normal looking renal remnant as seen on ultrasound.
Case 3 A 2-year-old male child with bilateral hydronephrosis due to bilateral PUJ obstruction initially underwent a left pyeloplasty. He re-presented at 4 years of age with increasing hydronephrosis of the right side. A right pyeloplasty was performed, which failed. A nephrostogram showed no flow of dye. The nephrostomy was retained for 3 months. DTPA renogram showed a differential function of 56% on the left and 44% on the right. At re-do surgery the upper and part of the middle third of the right ureter were found to be fibrosed and strictured. The lower ureter was of normal calibre. The entire right ureter was replaced by the appendix with the caecal end anastomosed to the dilated pelvis and the appendicular tip re-implanted to the
15 bladder. The appendix was myotomised prior to its use by splitting the sero-muscular layer. The postoperative nephrostogram shows good flow of dye from the pelvis past the appendicular graft into the bladder. There had been a reduction of the right hydronephrosis on US and the DTPA renogram showed improvement in drainage. At follow up of 44.6 months, the differential renal function was L Z 62% and R Z 38%.
Case 4 A 6-year-old male child presented with abdominal pain and was diagnosed as having right-sided congenital midureteric stenosis with gross hydroureteronephrosis on the right side, and a normal left kidney. Preoperatively an intravenous pyelogram showed gross hydronephrosis of the right side with dilatation of the upper ureter that was confirmed on ultrasound (which also revealed an abrupt cut off after the middle third of the ureter). A preoperative retrograde pyelogram revealed a mid-ureteric stenosis with function of L Z 39% and R Z 61%. Operatively stenosis of the ureter from the mid-ureteric level proceeding distally was found. The stenosed portion of the ureter was replaced using the myotomised appendix, anastomosing the caecal end to the dilated upper ureter and implanting the appendicular tip into the bladder. Postoperatively an IVP revealed a reduction in the right-sided hydronephrosis with flow from the pelvis past the upper ureter, through the appendix and into the bladder. A postoperative ultrasound showed no increase in the hydronephrosis while the DTPA renogram showed slow but improved drainage on the right side. The differential function was L Z 41%, R Z 59% at 7.6 months postoperatively. The child’s pain had been relieved.
Case 5 A 3-year-old female child was admitted with a history of recurrent UTI since birth. The child had global developmental delay. A preoperative ultrasound revealed a contracted right kidney with left hydronephrosis and a gross dilatation of the left upper ureter. Micturating cystourethrogram (MCUG) showed right-sided grade 4 VUR. DTPA renogram showed a dilated left renal pelvis, upper and middle ureter with functions of L Z 81% and R Z 19%. An intraoperative retrograde pyelogram showed a dilated upper third of the left ureter with stenosed middle and lower thirds. The stenosed parts of the ureters were excised. The right ureter was disconnected from the right renal pelvis and anastomosed to the dilated left ureter in an end-to-end manner, thus utilizing the right dilated ureter to provide drainage for the left kidney. The gap between the disconnected right renal pelvis and the right ureter was bridged with the appendix. The caecal end of the myotomised appendix was anastomosed to the right pelvis while the distal end was anastomosed in an end-to-side fashion to the dilated right ureter. Postoperative left nephrostogram showed patency of all anastomoses and drainage into the bladder. DTPA renogram showed normal drainage on the right side and slow drainage on the left side (L Z 33%, R Z 67%) at 34 months after the operation.
16
Table 1
Data for 10 cases of ureteric substitution using the appendix
Case no.
Age
Etiology
Previous Surgery
Preoperative imaging
Postoperative imaging
Follow up (months)
Complications
1
4 months
Nil
5 years
44.6
Nil
4
6 years
Congenital right mid-ureteric stenosis
Nil
Right hydroureteronephrosis; mid-ureteric stenosis; function 61%
7.6
Nil
5
3 years
Congenital left mid-ureteric stenosis
Nil
6
2 years
Stricture right ureter
7
1 year
Failed right pyeloplasty
8
4 months
Right ureteric stricture
9
2.5 months
10
8 years
Congenital right ureteric stenosis (horse-shoe kidney) Congenital left mid-ureteric stenosis
B/L ureteric re-implantation, right Anderson Hynes pyeloplasty, right loop ureterostomy B/L Anderson Hynes pyeloplasty, right nephrostomy Right Anderson Hynes pyeloplasty Nil
Left hydroureteronephrosis; mid-ureteric stenosis function 11%; right grade 4 VUR Right hydronephrosis; no drainage from pelvis; function 36%; B/L grade 1 VUR
Adequate drainage; function 33% Normal residual right kidney Adequate drainage; decreased hydronephrosis; function 38% Adequate drainage; decreased hydronephrosis; function 59% Adequate drainage; function 33%
24
3
Ureter length <1 cm; function 33%; no drainage from pelvis Right persistent urinoma; non-perfusion right lower pole Right hydronephrosis; no drainage from pelvis; function 44%
Nil
12 years
Right Anderson Hynes pyeloplasty 2 Nil
72
2
?Stenosis/stricture right ureter Traumatic right ureteric avulsion Stricture right ureter
B/L Anderson Hynes pyeloplasty
Left ureteric reimplantation
34
UTI (1 episode)
Adequate drainage
8
Nil
Right hydronephrosis; no drainage from pelvis; no tracer activity
Adequate drainage; function 12%
4.9
Nil
Right hydronephrosis; no drainage from pelvis Hydronephrosis and poor visualization (right moiety) Left hydroureteronephrosis; creatinine 4.7 mg/dl
Adequate drainage
1
Nil
60
Nil
1
Nil
Adequate drainage; decreased hydronephrosis Normal Whitaker test; creatinine 1.2 mg/dl
B/L, bilateral.
H. Dagash et al.
The appendix as ureteral substitute
Case 6 A 2-year-old male child was diagnosed at another centre with bilateral primary VUR. The child underwent bilateral ureteric re-implantation, following which he continued to have significant right-sided hydronephrosis, and a diagnosis of a right PUJ obstruction was made. This was treated by a pyeloplasty in the same hospital, following which the hydronephrosis persisted with recurrent infections. A rightsided high loop ureterostomy was then performed. Subsequently, he was referred to our institution. Preoperative MCUG revealed bilateral grade 1 VUR. A dye study through the ureterostomy revealed obstructed drainage from the pelvis into the ureter. Ultrasound showed gross hydronephrosis of the right kidney. DTPA renogram showed poor parenchymal uptake on the right side with poor clearance of the tracer, with functions L Z 64% and R Z 36%. Operatively a stricture of the upper third of the ureter was revealed. As there had been surgery on both the upper and lower ends of the ureter it was not considered prudent to interfere with the ureter. The myotomised appendix was used to bypass the strictured segment, with the caecal end anastomosed to the pelvis and the tip anastomosed to the dilated lower ureter over a double J stent with a nephrostomy. The ureterostomy was not closed at this point. Postoperatively the child was well with no recurrence of the UTI. A postoperative nephrostogram showed good drainage from the pelvis via the appendix into the lower ureter and further into the bladder. The child’s double J stent was removed and ureterostomy closed. At recent re-evaluation the right kidney function had deteriorated from 36% preoperatively to non-functioning.
Case 7 A 1-year-old male child was antenatally diagnosed to have bilateral PUJ obstruction and underwent a right pyeloplasty at 1 month of age. He re-presented with abdominal distension and a palpable mass on the right side. IVP and DTPA scan showed non-function of right kidney and left PUJ obstruction. The child underwent a left pyeloplasty and right nephrostomy which drained pus from the right kidney. Subsequent right nephrostogram showed no flow of the dye from the pelvis into the ureter. The child was again taken up for surgery and the entire right ureter was replaced by anastomosing the caecal end of the myotomised appendix to the pelvis and implanting the distal end to the bladder. The DTPA scan 5 months later showed tracer activity in the right renal bed with the differential function being 12% on the right and 88% on the left.
Case 8 A 4-month-old female child was diagnosed antenatally to have right PUJ obstruction. The child underwent a pyeloplasty at 2 months of age. At operation the ureteric calibre was narrow and did not admit a 3-Fr ureteric catheter. Following surgery there was no drainage from the right pelvis into the ureter. Nephrostomy drainage was continued but the pyeloplasty did not function (Fig. 1A). The myotomised appendix was used to replace the ureter by anastomosing
17 the caecal end to the pelvis and re-implanting the tip into the bladder. Postoperative nephrostogram showed good drainage of the dye from the pelvis, through the appendix into the bladder (Fig. 1B). On follow up 6 months later the right kidney showed 46% differential function.
Case 9 A 2.5-month-old male infant presented with a painless mass in the right half of the abdomen. Ultrasound revealed a horse-shoe kidney with hydronephrosis of the right moiety. The right ureter was not visualized. An IVP showed poor visualization of the right moiety. The left system was visualized normally. The right system was approached by a right infraumbilical incision. A very large right renal pelvis was found. The right ureter was aperistaltic and stenosed in its entire length, and did not admit a 3-Fr catheter. The isthmus of the horse-shoe was located at the level of aortic bifurcation. A single renal artery arose anteriorly from the aorta, just above the isthmus, and supplied the entire kidney. It gave branches first to the right system and finally ended supplying the left system (Fig. 2A). The appendix was used to replace the entire right ureter, in an antiperistaltic manner. A psoas hitch was also done on the right side (Fig. 2B). A 12-Fr Malecot’s catheter was left through the lower calyx as a nephrostomy. A 5-Fr trans-anastomotic tube was left passing into the bladder. A supra-pubic catheter was also left for bladder drainage. On the 14th day, the trans-anastomotic tube was removed and a nephrostogram was done under fluoroscopy (Fig. 3A). One year post surgery an ultrasonogram showed a significant decrease in the pelvi-calyceal dilatation (Fig. 3B). The patient remained well 5 years later.
Case 10 An 8-year-old boy presented with a very large solitary left hydronephrotic kidney with renal failure. Serum creatinine at presentation was 2.0 mg/dl. Ultrasound and MCUG revealed left hydroureteronephrosis with no reflux. Ureteric reimplantation was done with a presumptive diagnosis of obstructive megaureter. This failed to relieve the obstruction and he re-presented with a rise of serum creatinine to 4.7 mg/dl. A nephrostomy was placed and there was partial resolution of creatinine to 2.1 mg/dl. At re-exploration the left ureter was found to have multiple zones of severe stenosis with intervening areas of dilatation from the mid-ureter downwards. This unhealthy ureter was resected, and the gap between the dilated mid-ureter and bladder was bridged with the myotomised appendix. Though the follow up was short the serum creatinine has remained stable at 1.2 mg/ dl. Prior to removal of nephrostomy, a Whitaker test showed that the pressure difference between the kidney and bladder did not exceed 2 cm of H2O, demonstrating no obstruction to flow through the appendicular substitution of ureter.
Discussion Ureteral replacement in children is rarely needed, but when the situation does arise, the perfect substitute has
18
H. Dagash et al.
Figure 1 (A) Preoperative nephrostogram showing no drainage from the right renal pelvis. (B) Postoperative nephrostogram shows flow of dye from pelvis through ureter into bladder.
not yet been determined. The ileum has been used, as have the Fallopian tubes [2e4]. The appendix has been used as a conduit in continence vesicostomies (Mitrofanoff) [5] and also in biliary atresia [6]. A review of the literature revealed isolated reports on the use of the appendix as a ureteral substitute in children. In 1981, Martin used the appendix as a conduit from the pelvis of the right kidney to the left ureter in an 8-year-old boy with PUV and a right ureteric stricture [7]. Renal function was satisfactory 3.5 years later. Mesrobian and Azizkhan used the appendix to bridge the gap between right renal pelvis and left ureter in a 7-year-old girl with
dermatomyositis and ureteral necrosis [8]. An IVP after 3 months showed good renal function and she was clinically well at 6 months. Estevao-Costa used the appendix to bridge a 7-cm-long ureteral defect following trauma [9]. Two years postoperatively the differential renal function was 41% on the side of the replacement. The largest series in children to date was by Richter et al. [10]. They reported their results with three paediatric cases followed up at 4, 7 and 15 years. All patients had good renal function, and the authors concluded that these results support the use of the appendix as a right ureteral substitute in select cases.
Figure 2 Diagrammatic representation of pathology and surgery. (A) Horseshoe kidney with (a) atretic and aperistaltic right ureter and (b) a single renal artery. (B) The vermiform appendix has been interposed: (a) pelvis anastomosed with the base of the appendix, (b) psoas hitch and (c) tip of the appendix implanted into the bladder making a submucosal channel. (Nephrostomy and stent are not shown in this picture.)
The appendix as ureteral substitute
19
Figure 3 Postoperative imaging. (A) Nephrostogram done on 14th postoperative day showing dye going into the bladder through the appendix (arrow). (B) Ultrasonography done after 1 year showing the decompressed right pelvis and the patent conduit.
The appendix can be used as a conduit in ureteral substitution for a number of reasons. The appendix and ureter are similar in calibre [10]. The peristaltic properties of the appendix have been cited as an advantage over the use of Fallopian tubes [11]. Most reports do not define the orientation of the appendix, and in our series all were placed in an anti-peristaltic manner. Also, because of the small mucosal surface area, there is no relevant absorption of sodium chloride and urea; hence no electrolyte disturbances are seen, which is a potential problem when ileum is used. Disproportion between the ureter and appendix (ureteral calibre being much larger) may be overcome by including a caecal cuff, allowing a more secure anastomosis [8]. We employed a caecal cuff for anastomosis to the renal pelvis in all cases. A longitudinal myotomy was done in all the cases from Vellore after placing the graft in an antiperistaltic fashion, to avoid the ill effects of reverse peristalsis. There are also reported disadvantages to using the appendix. Potential problems are stenosis, fistula formation and anastomotic breakdown. The latter complication was found to be higher in iso-peristaltic interposition, especially at the superior anastomosis [12,13]. A review of the literature failed to reveal any cases of anastomotic breakdown when the appendix was interposed in an antiperistaltic manner. We agree with Estevao-Costa that antiperistaltic interposition is probably of no real functional significance, but it does theoretically reduce torsion of the mesoappendix and thus prevents any further vascular compromise [9]. Some authors advocate the use of mucolytic agents such as acetylcysteine for preventing mucinous obstruction [14]. This agent has been shown both in vitro and in vivo to relieve mucinous obstruction when a bowel segment was used for ureteral interposition [15,16]. Benderev encountered mucinous obstruction in an ileal segment interposition and successfully cleared it by instillation of acetylcysteine via a nephrostomy [16]. We have not encountered any cases of mucinous obstruction when using the appendix. In conclusion, we report nine cases where the appendix was used as right ureteral substitute and one where the left ureter was substituted, with good results in all but one
case, and conclude that this technique is feasible and safe, even in infants.
References [1] Melnikoff AE. Sur le replacement de l’uretere par anse isolee de l’intestine grele. Rev Clin Urol 1912;1:601e3. [2] Boxer RJ, Johnson SF, Ehrlich RM. Ureteral substitution. Urology 1978;12:269e78. [3] Boxer RJ, Fritzsche P, Skinner DG, Kaufman JJ, Belt E, Smith RB, et al. Replacement of the ureter by small intestine: clinical application and results of the ileal ureter in 89 patients. J Urol 1979;121:728e31. [4] Duncan RE, Evans AT. Fallopian tube as ureteral substitute in a living donor renal allograft. Br J Urol 1975;47:300. [5] Mitrofanoff P. [Trans-appendicular continent cystostomy in the management of the neurogenic bladder]. Chir Pediatr 1980;21:297e305. [6] Valla JS. Hepaticoportoappendicostomy. J Pediatr Surg 1988; 23:1057e8. [7] Martin LW. Use of the appendix to replace a ureter. Case report. J Pediatr Surg 1981;16:799e800. [8] Mesrobian HG, Azizkhan RG. Pyeloureterostomy with appendiceal interposition. J Urol 1989;142:1288e9. [9] Estevao-Costa J. Autotransplantation of the vermiform appendix for ureteral substitution. J Pediatr Surg 1999;34:1521e3. [10] Richter F, Stock JA, Hanna MK. The appendix as right ureteral substitute in children. J Urol 2000;163:1908e12. [11] Komatz Y, Itoh H. A case of ureteral injury repaired with appendix. J Urol 1990;144:132e3. [12] Lloyd SN, Kennedy C. Autotransplantation of the vermiform appendix following ureteroscopic damage to the right ureter. Br J Urol 1989;63:216e7. [13] Fernandez Fernandez A, Soria Ruiz S, Gomez Martinez I, Gil Fabra J, Martinez Castellan ˜os F, Otero Mauricio G. Blunt traumatic rupture of the high right ureter repaired with appendix interposition. Urol Int 1994;53:97e8. [14] Jang TL, Matschke HM, Rubenstein JN, Gonzalez CM. Pyeloureterostomy with interposition of the appendix. J Urol 2002; 168:2106e7. [15] Gillon G, Mundy AR. The dissolution of urinary mucus after cystoplasty. Br J Urol 1989;63:372e4. [16] Benderev TV. Acetylcysteine for urinary tract mucolysis. J Urol 1988;139:353e4.