Pediatric Nephrology
Pediatr Nephrol(1992) 6:399-402 9 IPNA 1992
Literature review - Urology
Ureteropelvic junction obstruction in childhood R. Wammack, M. Fiseh, and R. Hohenfellner Department of Urology, University of Mainz School of Medicine, Mainz, Federal Republic of Germany Received March 10, 1992 and accepted March 13, 1992
Due to routine obstetric ultrasound screening, clinicians have been confronted with an increasing number of neonates presenting with antenatally detected upper urinary tract dilatation. The underlying pathology and significance are sometimes difficult to assess. Ureteropelvic junction (UPJ) obstruction is the most frequently diagnosed form of fetal uropathy. Its management and indications for surgery are highly controversial, since the natural history of the disease is unknown. The most popular plastic procbdure for correction of UPJ obstruction is the AndersonHynes dismembered pyeloplasty. However, currently endoscopic procedures are being implemented with increasing frequency.
The authors report on the treatment of four patients, 6.5 weeks to 5.5 years old, who underwent percutaneous endopyelotomy following failed open dismembered pyeloplasty. Two patients had become symptomatic following open pyeloplasty after the drainage tubes had been removed. In the other two children UPJ obstruction persisted for 6 and 10 weeks respectively after open surgery. For endopyelotomy a guide-wire was passed from the bladder into the renal pelvis. The nephrostomy tract was dilated until an endoscope could be inserted into the collecting system. Subsequently, the guide-wire was retrieved which created through-and-through access to the kidney. The patients were prepared for open surgery if the wire could not be passed across the UPJ. Endopyelotomy was performed using a 3-F or 5-F electrocautery probe. The postolateral surface of the UPJ was incised until periureteral fat was clearly seen. Contrast media applied through the endoscope demonstrated marked extravasation at the UPJ. A balloon was then inflated to 1 atrn in order to
separate the cut edges and identify insufficiently incised areas. A ureteral stent and a nephrostomy tube were inserted. The ureteral stent was left in place for 6 weeks. Average procedure time was 3.5 h. The obstruction was relieved in all four patients directly after the operation, however two of the four patients required secondary endoscopic procedures thereafter. T h e follow-up period ranged from 18 to 36 months post-operatively (mean 25.5 months). The authors mention that persistent obstruction after open surgery necessitates leaving the nephrostomy tube in place for an undetermined and possibly long period, putting the patient at risk of tube dislodgement and recurrent infection. Moreover, advocates of endopyelotomy argue that this procedure could reduce these risks and solve the problem quickly with minimal invasiveness. It must be borne in mind that UPJ obstruction may persist in some patients following open pyeloplasty. This is frequently due to an oedema at the anastomosis site. The interval between open pyeloplasty and endopyelotomy was 5.5, 6 and 10 weeks in three of the four patients. This is too short, as such oedema can take months to subside. The differential diagnosis between genuine re-stricturing due to fibrous tissue formation and obstruction due to oedema is most difficult. We believe that neither a nephrostogram nor a diuretic renogram is able to establish.the correct diagnosis. A walt-and-see approach is the beast solution in our opinion. As the authors state, there is a risk of tube dislodgement during long-term nephrostomy, especially in children. The same holds true for recurrent infections. However, the authors leave the ureteral stent and the nephrostomy tube in place for 6 weeks. After dismembered pyeloplasty the stent is usually removed around the 8th post-operative day. Hence the authors' invasive approach to post-pyeloplasty obstruction entails the same if not a greater risk of infection and tube dislodgement. Moreover, the 3.5-h surgery and anaesthesia should not be overlooked.
400
s The paper presents a review of eight series of endopyelotomy described in the literature. Apart from one author, who reports on his experience using this technique on two children, the papers deal mostly with adult patients. Success rates of 7 2 % - 9 8 % have been reported for open pyelopasty. Several alternatives to classical open pyelotomy are described. Davis is credited with the development of the technique of intubated ureterotomy. A ureteral stent was considered as a mould around which regenerating tissue would proliferate after incision to form a ureteral channel of normal size and shape. The stent was to be left in place until the ureteral musculature had completely healed. Another alternative described is balloon dilatation. The authors mention that they have performed early retrograde balloon dilatation successfully for pyeloplasty failure in three children, the youngest of whom was a 2-month-old girl. It is emphasised that prolonged stenting, usually via an internalised double-J catheter, is a key factor in maintaining patency of the dilated area. The authors conclude that endopyelotomy has several distinct advantages o v e r open surgery, including the decreased morbidityand associated expense of an open operation and minimal interference with the blood supply of the ureter. It is further suggested that the techniques developed in adults should be progressively applied to younger and smaller children. Open infant pyeloplasty is a highly successful procedure, accompanied by minimal morbidity and accomplished during a hospital stay of a few days. The socio economic factors are obviated in the infant, who already requires constant maternal care. It is suggested that endopyelotomy deserves consideration in the older child, especially if the obstruction is secondary in nature after a previous open procedure. The authors have succeeded in nicely summarising the historical and surgical aspects of UPJ obstruction. Beginning with the percutaneous nephrostomy, endourological techniques are meticulously described and depicted. Although the title suggests that the focus is on the treatment of UPJ obstruction in children, the series reviewed and the success rates cited mostly concern adults. Moreover, the authors' preference for endoscopic procedures is very clear. Balloon dilatation of ureteral strictures has been reported by many authors with much less favourable results. A large series was published by Lang and Glorioso (1988) (AJR 150: 131). They reported a success rate of only 50% during their 15-month follow-up after balloon dilatation o f 127 benign strictures. As discussed by the authors of the previous paper, it must be stressed that long-term followup is essential to adequately assess the outcome of treatment after UPJ obstruction. In 1988 Sabha et al. (J Endourol 2: 23) reported a 60% success rate at 6 months when using balloon dilatation for bilharzial ureteral strictures, but only a 10% patency in patients at I-year follow-up.
Kramolowsky et al. (1987) (J Urol 137: 390) reported 100% recurrence of strictures in patients with ureteroenteral anastomotic strictures treated by dilatation. This demonstrates a profound inconsistency of balloon dilatation in treating ureteral strictures. Endopyelotomy seems to be a modification of the Davis intubated ureterotomy procedure, the difference being that the incision is not made from the "outside" during open surgery but from the "inside" by means of endoscopy. Experience with the Davis ureterotomy procedure, first described in 1943, was unfavourable and this technique was subsequently abandoned. Nowadays, in the era of endoscopic surgery, ureterotomy has become again popular despite this experience. Its advocates emphasise the minimal invasiveness of the procedure. However, in view of the small size of the infant' s ureter and the small boy' s urethra, and the well-known risks of endoscopic manipulation, it is hard to accept this therapy as being minimally invasive. Permanent UPJ obstruction after open pyeloplasty in the infant or child is very rare. As discussed, mechanical obstruction due to oedema as well as functional obstruction due to abnormalities of ureteral peristalsis occur in some cases and may take months to subside. A wait-and-see approach under the protection of a percutaneous nephrostomy tube is associated with less risk than surgery, be it endoscopic or open. Widespread pre- and post-natal ultrasonography screening has had an immense impact on paediatric urology. Treatment can be implemented earlier. However, a dilemma has resulted. When should intervention take place? When should, if at all, a nephrostomy tube be inserted? When should upper urinary tract obstruction be treated? What is the natural course of fetal hydronephrosis?
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Pediatr Nephrol(1992) 6:399-402 9 IPNA 1992
Literature review - Urology
Ureteropelvic junction obstruction in childhood R. Wammack, M. Fiseh, and R. Hohenfellner Department of Urology, University of Mainz School of Medicine, Mainz, Federal Republic of Germany Received March 10, 1992 and accepted March 13, 1992
Due to routine obstetric ultrasound screening, clinicians have been confronted with an increasing number of neonates presenting with antenatally detected upper urinary tract dilatation. The underlying pathology and significance are sometimes difficult to assess. Ureteropelvic junction (UPJ) obstruction is the most frequently diagnosed form of fetal uropathy. Its management and indications for surgery are highly controversial, since the natural history of the disease is unknown. The most popular plastic procbdure for correction of UPJ obstruction is the AndersonHynes dismembered pyeloplasty. However, currently endoscopic procedures are being implemented with increasing frequency.
The authors report on the treatment of four patients, 6.5 weeks to 5.5 years old, who underwent percutaneous endopyelotomy following failed open dismembered pyeloplasty. Two patients had become symptomatic following open pyeloplasty after the drainage tubes had been removed. In the other two children UPJ obstruction persisted for 6 and 10 weeks respectively after open surgery. For endopyelotomy a guide-wire was passed from the bladder into the renal pelvis. The nephrostomy tract was dilated until an endoscope could be inserted into the collecting system. Subsequently, the guide-wire was retrieved which created through-and-through access to the kidney. The patients were prepared for open surgery if the wire could not be passed across the UPJ. Endopyelotomy was performed using a 3-F or 5-F electrocautery probe. The postolateral surface of the UPJ was incised until periureteral fat was clearly seen. Contrast media applied through the endoscope demonstrated marked extravasation at the UPJ. A balloon was then inflated to 1 atrn in order to
separate the cut edges and identify insufficiently incised areas. A ureteral stent and a nephrostomy tube were inserted. The ureteral stent was left in place for 6 weeks. Average procedure time was 3.5 h. The obstruction was relieved in all four patients directly after the operation, however two of the four patients required secondary endoscopic procedures thereafter. T h e follow-up period ranged from 18 to 36 months post-operatively (mean 25.5 months). The authors mention that persistent obstruction after open surgery necessitates leaving the nephrostomy tube in place for an undetermined and possibly long period, putting the patient at risk of tube dislodgement and recurrent infection. Moreover, advocates of endopyelotomy argue that this procedure could reduce these risks and solve the problem quickly with minimal invasiveness. It must be borne in mind that UPJ obstruction may persist in some patients following open pyeloplasty. This is frequently due to an oedema at the anastomosis site. The interval between open pyeloplasty and endopyelotomy was 5.5, 6 and 10 weeks in three of the four patients. This is too short, as such oedema can take months to subside. The differential diagnosis between genuine re-stricturing due to fibrous tissue formation and obstruction due to oedema is most difficult. We believe that neither a nephrostogram nor a diuretic renogram is able to establish.the correct diagnosis. A walt-and-see approach is the beast solution in our opinion. As the authors state, there is a risk of tube dislodgement during long-term nephrostomy, especially in children. The same holds true for recurrent infections. However, the authors leave the ureteral stent and the nephrostomy tube in place for 6 weeks. After dismembered pyeloplasty the stent is usually removed around the 8th post-operative day. Hence the authors' invasive approach to post-pyeloplasty obstruction entails the same if not a greater risk of infection and tube dislodgement. Moreover, the 3.5-h surgery and anaesthesia should not be overlooked.
400
s The paper presents a review of eight series of endopyelotomy described in the literature. Apart from one author, who reports on his experience using this technique on two children, the papers deal mostly with adult patients. Success rates of 7 2 % - 9 8 % have been reported for open pyelopasty. Several alternatives to classical open pyelotomy are described. Davis is credited with the development of the technique of intubated ureterotomy. A ureteral stent was considered as a mould around which regenerating tissue would proliferate after incision to form a ureteral channel of normal size and shape. The stent was to be left in place until the ureteral musculature had completely healed. Another alternative described is balloon dilatation. The authors mention that they have performed early retrograde balloon dilatation successfully for pyeloplasty failure in three children, the youngest of whom was a 2-month-old girl. It is emphasised that prolonged stenting, usually via an internalised double-J catheter, is a key factor in maintaining patency of the dilated area. The authors conclude that endopyelotomy has several distinct advantages o v e r open surgery, including the decreased morbidityand associated expense of an open operation and minimal interference with the blood supply of the ureter. It is further suggested that the techniques developed in adults should be progressively applied to younger and smaller children. Open infant pyeloplasty is a highly successful procedure, accompanied by minimal morbidity and accomplished during a hospital stay of a few days. The socio economic factors are obviated in the infant, who already requires constant maternal care. It is suggested that endopyelotomy deserves consideration in the older child, especially if the obstruction is secondary in nature after a previous open procedure. The authors have succeeded in nicely summarising the historical and surgical aspects of UPJ obstruction. Beginning with the percutaneous nephrostomy, endourological techniques are meticulously described and depicted. Although the title suggests that the focus is on the treatment of UPJ obstruction in children, the series reviewed and the success rates cited mostly concern adults. Moreover, the authors' preference for endoscopic procedures is very clear. Balloon dilatation of ureteral strictures has been reported by many authors with much less favourable results. A large series was published by Lang and Glorioso (1988) (AJR 150: 131). They reported a success rate of only 50% during their 15-month follow-up after balloon dilatation o f 127 benign strictures. As discussed by the authors of the previous paper, it must be stressed that long-term followup is essential to adequately assess the outcome of treatment after UPJ obstruction. In 1988 Sabha et al. (J Endourol 2: 23) reported a 60% success rate at 6 months when using balloon dilatation for bilharzial ureteral strictures, but only a 10% patency in patients at I-year follow-up.
Kramolowsky et al. (1987) (J Urol 137: 390) reported 100% recurrence of strictures in patients with ureteroenteral anastomotic strictures treated by dilatation. This demonstrates a profound inconsistency of balloon dilatation in treating ureteral strictures. Endopyelotomy seems to be a modification of the Davis intubated ureterotomy procedure, the difference being that the incision is not made from the "outside" during open surgery but from the "inside" by means of endoscopy. Experience with the Davis ureterotomy procedure, first described in 1943, was unfavourable and this technique was subsequently abandoned. Nowadays, in the era of endoscopic surgery, ureterotomy has become again popular despite this experience. Its advocates emphasise the minimal invasiveness of the procedure. However, in view of the small size of the infant' s ureter and the small boy' s urethra, and the well-known risks of endoscopic manipulation, it is hard to accept this therapy as being minimally invasive. Permanent UPJ obstruction after open pyeloplasty in the infant or child is very rare. As discussed, mechanical obstruction due to oedema as well as functional obstruction due to abnormalities of ureteral peristalsis occur in some cases and may take months to subside. A wait-and-see approach under the protection of a percutaneous nephrostomy tube is associated with less risk than surgery, be it endoscopic or open. Widespread pre- and post-natal ultrasonography screening has had an immense impact on paediatric urology. Treatment can be implemented earlier. However, a dilemma has resulted. When should intervention take place? When should, if at all, a nephrostomy tube be inserted? When should upper urinary tract obstruction be treated? What is the natural course of fetal hydronephrosis?
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