Open pyeloplasty remained the standard treatment until the mid-1980s. The advantages of the open pyeloplasty include mucosa-to-mucosa anastomosis and excision of redundant renal pelvis and diseased ureter. Over the past decade, antegrade endopyelotomy has evolved as the treatment of choice for obstructions of the UPJ. Further experience has shown that primary UPJ obstruction responded equally well, with long-term success rates for both groups of patients approaching 85%. Endopyelotomy results in significantly less morbidity, and should this technique fail, subsequent open pyeloplasty is no more difficult than had it been performed initially. A 20% incidence of stones associated with UPJ obstruction has been reported. Antegrade endopyelotomy can treat these patients simultaneously. Our series of more than 400 endopyelotomies showed that success was based on the degree of preoperative hydronephrosis and renal function. The presence of massive hydronephrosis had a pejorative influence on endopyelotomy, lowering the success rate from 96% to 50%. Similarly poor renal function (less than 25% of total function) reduced the success rate from 92% to 54%. Although not as extensively reported in the urologic literature, indeed fewer patients with fewer follow-ups have undergone a ureteroscopic endopyelotomy compared with an antegrade endopyelotomy, success rates have ranged between 79% and 94%. Nephrectomy was required in 2.5% for bleeding and 5% for poor renal function. In patients with primary UPJ obstruction, Acucise has a success rate that is 15% lower than antegrade endopyelotomy. Acucise endopyelotomy is a blind procedure, with 1.5% of bleeding reported requiring transfusion and 3% has undergone postoperative embolization. Laparoscopic pyeloplasty is also a relatively new technique which has only been reported with some extensive experience in two institutions, although the success rate has been extremely high, despite a short follow-up. Overall, the incidence of crossing vessels at the UPJ is approximately 50%. The greatest problem lies in determining whether a crossing vessel is etiologically or clinically significant. Thus, the presence of a crossing vessel was potentially causally related to endopyelotomy failure in 4% of the patients. Our overall success rate of 78% for endopyelotomy is comparable and sometimes higher than the reported success rate for open pyeloplasty for horseshoe kidneys, which ranged from 55 to 80%. However, endopyelotomy has become an established treatment modality in the adult, with a decreased morbidity in comparison with open pyeloplasty. The benefits of endourologic management of pediatric UPJ obstruction are less well established.
Conclusions: Endopyelotomy is a safe and effective treatment for primary and secondary UPJ obstruction for most patients. The biggest experience with better results has been reported with antegrade endopyelotomy, which permits the treatment of associated stones. Laparoscopic pyeloplasty, which is technically demanding, may be considered the best treatment in patients with severe hydronephrosis and poor renal function, which resulted in a success rate of only 38% and 57%, respectively, with endopyelotomy. If we are going to minimize morbidity for our patients, open pyeloplasty is only the first choice for neonates and younger children, and should be considered in patients after failed endopyelotomy.