Kidney Transplant Ureteroneocystostomy Techniques and ...

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1416 KAYLER, KANG, MOLMENTI ET AL Fig 4. Full-thickness technique. A cystostomy is made through all layers of the bladder. The spatulated ureter is continuously sutured to the full thickness of the bladder (mucosa, musculature, and serosa) using absorbable suture. There is no additional closure of the bladder muscle layer over the anastomosis. whether the high rate of leakage in the U-stitch group could have been prevented. One retrospective study by Lucas et al 28 reported an absence of leaks in 112 kidney transplant recipients who underwent a antireflux technique versus 52 recipients transplanted with a non-antireflux technique (n 52). In both methods, parallel incisions were made for intravesicular access to the bladder and the urothelial anastomosis incorporated bladder muscularis. In the antireflux group, the tunnel was performed in the submucosal layer by blunt dissection with a tonsil clamp, and for the other group there was no attempt to tunnel the ureter. Anastomotic urine leaks can be ureteral or vesical in origin. 13 Extravesical techniques decrease the risk of leaks by obviating the need for a separate cystostomy. Technical issues may arise with the LG technique when the bladder mucosa is extremely thin, allowing for urine filtration through 1 or more suture orifices or when the thin mucosa tears away from the suture lines. 13 Urine leakage with the U-stitch technique has been attributed to the lack of a mucosal-to-mucosal anastomosis. 11 The incorporation of muscularis in the anastomosis in both groups in the study by Lucas et al 28 may have strengthened the anastomosis against leakage. Nontechnical risk factors for the development of urine leakage include: recipient age, number of renal arteries, site of arterial anastomosis, the occurrence of acute rejection episodes, bladder problems, and immunosuppressive regimen. 31 Ureteral Obstruction In comparative studies, the incidence of ureteral obstruction ranges from 1% to 8.3% (Table 1). Four retrospective 1,3,5,7 plus 1 prospective 2 analyses did not demonstrate any significant difference in the proportion of ureteral obstructions between the LG and LP techniques; however, 2 studies 4,6 reported significant but conflicting findings comparing LP to LG. In a retrospective analysis, Thrasher et al 4 observed significantly higher proportions of ureteral obstruction overall in the LP (5.6%) compared to the LG (1.3%) group, specifically identifying obstruction at the ureterovesicle junction (UVJ) to be the main reason for the difference (1/160 LG vs. 6/160 LP, P .05). In this study, a single surgeon performed both types of implantation during 2 different eras under identical immunosuppression. The groups were well matched in terms of recipient age, renal allograft source, and diabetic status, but significantly more men underwent LP implantation. Gender, however, is not known to be a risk factor for UVJ obstruction. The authors believed that the difference in UVJ obstruction related to technique, citing several disadvantages of the LP technique including: (1) UVJ obstruction due to kinking of the ureter within the new muscular hiatus in the bladder, (2) damage to the adventitial blood supply while handling the terminal ureter during placement in the submucosal tunnel with subsequent ischemia and stenosis, and (3) increased risk of the distal ureter to ischemic injury in the LP due to the greater ureteral length needed to perform the technique. An advantage of extravesical techniques for prevention of ureteral stenosis is the ability to use a shorter segment of the ureter and possibly decreased handling of the ureter. In contrast, another study by Waltke et al, 6 in which 131 patients were prospectively randomized to 1 of 2 techniques, reported a 0% anastomotic obstruction rate with LP implantation performed by 1 of 2 surgeons who utilized stents in all cases compared to 6.3% with the LG technique performed by a third surgeon without stent usage (P .05). The groups were otherwise comparable in terms of age, sex,
KIDNEY TRANSPLANT LITERATURE REVIEW 1417 etiology of end-stage renal disease, and immunosuppression. The authors did not provide a definitive cause of obstruction and hypothesized that it was related to anastomotic scarring or placement of the ureteroneocystostomy on the dome of the bladder. 6 They did not discuss the potential selection bias introduced by various surgeons performing different techniques or the disparities in stent usage. Most comparative analyses have shown no differences in ureteral obstruction rates between the LG and U-stitch methods. 3,8,10–13 However, in one report the U-stitch group showed a higher proportion of ureteral obstructions compared to the LG group (3.1% vs. 0.3%, respectively, P .003). 9 In this retrospective study, patients were well matched for demographic factors; however, differences may have been due to surgeon inexperience since it involved surgeons who typically performed the LG implantation, with 2 surgeons performing the U-stitch instead of the LG technique during 19 of the 27-month study period. Also, a Table 1. Urologic Complications in Comparative Studies Ref. Year F/U Type DD (%) Stent (%) Leak (%) Obstruction a (%) Hematuria b (%) Reflux c (%) 1 2009 2 y LG NR 92 8/412 (1.9) 13/412 (3.2) NR NR LP NR 100 9/265 (3.4) 12/265 (4.5) NR NR 2 1995 d NR LG 50 5/150 (3.3) 5/150 (3.3) 2/150 (1.3) e LP 50 8/150 (5.3) 8/150 (5.3) 22/150 (14.7) 3 1994 4 m LG NR 0 4/295 (1.4) 3/295 (1.0) 1/295 (0.3) U NR 0 2/481 (0.004) 22/481 (4.6) 6/481 (1.3) LP NR 0 7/410 (1.7) 18/410 (4.0) 7/410 (1.7) 4 1990 LG 76 NR 2/160 (1.3) 2/160 (1.3) e NR NR LP 88 NR 2/160 (1.3) 9/160 (5.6) NR NR 5 1988 NR LG 0 NR 2/125 (1.6) 1/125 (0.8) NR NR LP 0 NR 5/125 (3.2) 0/125 (0) NR NR 6 1982 d NR LG 100 100 2/72 (2.8) 6/72 (8.3) e NR NR LP 100 0 2/59 (3.4) 0/59 (0) NR NR 7 1977 5 m LG NR NR 1/133 (0.8) e 5/133 (3.8) NR NR LP NR NR 10/108 (9.3) 1/108 (0.9) NR NR 8 2007 f LG 73 14 6/238 (2.5) 5/238 (2.1) 3/238 (1.3) e 2/238 (0.8) U 93 17 6/73 (8.2) 3/73 (4.1) 6/73 (8.2) 1/73 (1.4) 9 2007 3 y LG NR 20 8/360 (2.2) e 1/360 (0.3) e 5/360 (1.4) e U NR 24 20/353 (5.7) 11/353 (3.1) 21/353 (5.9) 10 2007 NR LG NR NR 6/217 (2.8) 3/217 (1.4) NR NR 0/217 (0) U NR NR 2/60 (3.3) 1/60 (1.7) NR NR 0/60 (0) 11 2005 d f LG 100 100 1/100 (1.0) 2/100 (2.0) 1/100 (1.0) U 100 100 0/44 (0.0) 1/44 (2.2) 3/44 (6.8) 12 2003 1 y LG 73 NR 5/148 (3.4) 11/148 (7.4) 5/148 (3.4) e U 83 NR 0/64 (0) 2/64 (3.1) 22/64 (34.0) 13 2002 f LG 36 0 22/416 (5.3) 23/416 (5.5) 6/416 (1.4) e 8/416 (1.9) U 72 e 0 11/159 (6.9) 7/159 (4.4) 5/159 (3.1) 0/159 (0) DD, deceased-donor; F/U, follow-up minimum; NR, not reported; LG, Lich-Gregoir; LP, Leadbetter-Politano; U, U-stitch; Ref, reference. a Includes ureteropelvic and ureterovesical obstruction. When data were available, we excluded cases of obstruction that were not related to technique, including stone, lymphocele, spermatic cord compression, hematoma, tumor, etc. Exclusion of cases did not change the significance of any of the findings, but reflects the incidence of complications that may be more attributable to technique for the purposes of this review. b Hematuria was defined as requirement for continuous bladder irrigation and bedside clot evacuation, cystoscopy for clot evacuation or fulguration, or reoperation for bleeding or complications of hematuria for reference 9. For references 11 and 3, hematuria was defined as the requirement of cystoscopy or surgery only. Definitions were not provided in the remaining studies. c Symptomatic reflux only. VCUG not routinely performed. d Prospective randomized trial. e Significant difference between the 2 groups of the same study (P .05). f Ref. 8, mean follow-up between the 2 groups was similar, 33.4 months for LG and 37 months for U-stitch. Ref. 11, mean follow-up was 12 and 8 months for LG and U-stitch. Ref 13, median follow-up was significantly longer in the LG group (76.6 months) than the U-stitch group (23.8 months). However, 90% of cases in the U-stitch group were followed up for more than 1 year. more meaningful comparison of various operative techniques is made when the incidence of ureterovesical junction obstruction is used; unfortunately, the sites of the ureteral obstructions were not provided in this study. Only 1 comparative study evaluated ureteral obstruction between antireflux and non- antireflux techniques, observing favorable experiences of zero leaks in both groups. 28 Although some causes of ureteral obstruction include fluid collections, adhesions, tumor, stones, blod clots, or compression by the round ligament or the spermatic cord, the majority are due to strictures, 4 which are believed to be related to ischemia or to rejection events. 32 The sole arterial supply of the transplant ureter is the descending branch of the main artery or of its lower polar branch. Damage to these vessels can easily be sustained during organ recovery, particularly if the hilum is dissected too enthusiastically or if there is skeletonizing or inadvertent stretching of the ureter. 33,34 Any trivial mishandling of the ureter may jeopardize the tiny periureteral arterial branches,
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