Renal Transplantation in Recipients With Modified Lower Urinary Tract: A Systematic Review and Implications for Adult Transplant Practice

Abstract

Background:

Adults with a modified lower urinary tract (MLUT) represent a growing but understudied population in renal transplantation. Concerns regarding long-term graft survival, infection, and urological morbidity persist, yet adult-specific outcome synthesis and clinically useful guidance are lacking.

Methods:

We performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of studies reporting posttransplant outcomes in adults with abnormal or surgically MLUT anatomy. Primary outcomes were 1- and 5-y graft and patient survival. Secondary outcomes included urological complications. Given substantial heterogeneity, data were synthesized narratively.

Results:

Twenty-four studies, including 511 MLUT recipients, were identified. Most were retrospective single-center series, and only a minority included comparator cohorts. Several studies included mixed adult-pediatric cohorts where adult-only outcomes could not be separated. Across comparative studies, 1-y graft survival appeared broadly similar between MLUT and control recipients, whereas 5-y graft survival was more often lower in MLUT cohorts. Patient survival was comparable, although long-term comparative data were limited. Urological morbidity was consistently greater in MLUT recipients, particularly recurrent urinary tract infection and the need for further urological intervention.

Conclusions:

Renal transplantation in selected adults with MLUT is achievable with acceptable early outcomes, but the burden of urological morbidity is substantial, and longer-term graft outcomes are less favorable. These findings support careful pretransplant lower urinary tract assessment and highlight the need for pragmatic optimization pathways, although higher-quality prospective data remain necessary.

INTRODUCTION

Successful renal transplantation (RT) depends not only on immunological and surgical factors but also on the presence of a “safe” urinary tract, which can store urine at a low pressure and empty reliably.¹ The presence of an unsafe reservoir exposes the graft to recurrent infections, upper tract deterioration, and vesicoureteral reflux, possibly culminating in impaired long-term function.² Historically, patients with abnormal or surgically modified bladders were therefore deemed poor candidates for transplantation, owing to technical complexities, urological morbidity, and graft loss.^3-5

This has changed in the pediatric population because of a better understanding of these abnormalities, their management, and how that impacts transplantation.⁵ This issue is increasingly relevant in adult transplant practice. With advances in pediatric urology and reconstructive practices, more patients with congenital lower urinary tract pathology now survive into adulthood and reach RT after previous surgeries on the bladder (augmentation, ileal conduits, continent catheterizable channels, etc.).^6,7 In addition, adults with acquired lower urinary tract dysfunction and detrusor dysfunction may also require reconstructive management before transplantation. Consequently, transplant teams are encountering a growing but highly heterogeneous population of recipients with an abnormal or surgically modified lower urinary tract (MLUT), encompassing diverse pathologies, previous reconstructive procedures, and functional impairment. Despite increasing clinical exposure to these patients, the evidence base guiding transplant decision-making remains fragmented.

RT in the setting of a MLUT poses a unique set of challenges and requires careful consideration. Reconstructed bladders differ substantially from native bladders in anatomy, compliance, emptying capability, bacteriological profile, and long-term complication burden.^4,8 In addition, practice remains inconsistent with respect to pretransplant evaluation, timing and choice of reconstruction, and postoperative surveillance. The majority of current practice relies heavily on anecdotes and institutional experiences rather than a coherent synthesis of available literature.^9,10 This creates uncertainty for clinicians and patients alike regarding feasibility and outcomes, as well as optimization of the urinary tract before undertaking RT.

Despite the growing clinical relevance of this problem, adult-focused evidence synthesis remains limited. Most published data consist of small retrospective single-center series, often spanning experience across several decades, with significant heterogeneity. Previous reviews have largely focused on the pediatric population or have not inculcated an integrated outcome synthesis with a practical framework for pretransplant optimization.

This systematic review therefore aimed to synthesize contemporary evidence on graft survival (GS), patient survival, and urological complications following RT in adults with MLUT. Because several eligible studies reported mixed adult-pediatric cohorts without separable adult data, the synthesis includes mixed-cohort evidence where relevant to adult transplant practice. In addition, we sought to develop a pragmatic clinical optimization framework, informed by the available literature and established principles of reconstructive surgery, to support pre-RT assessment, perioperative planning, and shared decision-making in this complex cohort.

METHODOLOGY

Protocol and Registration

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. The study protocol was registered on International Prospective Register of Systematic Reviews (CRD420251232353).

Search Strategy

A comprehensive search was undertaken of electronic databases including Medical Literature Analysis and Retrieval System Online via PubMed and OVID), Excerpta Medica dataBASE, SCOPUS, Web of Science, and the Cochrane Central Register of Controlled Trials until April 30, 2026.

No limits on dates or language were applied. Bibliographies of the included studies were hand-searched to identify further potentially relevant literature. The search results were exported to Rayyan software for screening and evaluation.¹¹ The detailed search strategy has been provided in Supplementary Appendix 1 (SDC, https://links.lww.com/TXD/A917).

Eligibility Criteria

Studies were eligible for inclusion if they met all the criteria outlined in Table 1.

TABLE 1.

Inclusion and exclusion criteria

Domain	Inclusion criteria	Exclusion criteria
Population	Kidney or kidney-pancreas transplant recipients, adults (≥18years) with MLUT	Pediatric-only cohorts
Mixed cohorts	Mixed adult-pediatric cohorts where adult outcomes were part of reported series and were not separable This group was included as it provided the dominant form of evidence owing to most adults undergoing reconstruction as children	Studies in which the cohort was entirely pediatric or did not relate to transplant recipients with lower urinary tract abnormalities
Exposure	Abnormal or surgically MLUT anatomy. This included augmentation cystoplasty, continent catheterizable channels (Mitrofanoff, etc.), urinary diversion (ileal conduit, etc.), high-pressure/small-capacity bladders corrected surgically, neuropathic bladders with surgical modification, etc	Studies not involving abnormal or MLUT anatomy
Outcomes	At least 1 post-transplant outcome of interest, including graft survival, patient survival, urinary tract infection, urosepsis, need for further urological intervention, or continence-related outcomes	Studies without relevant post-transplant outcome reporting
Study design	Comparative and noncomparative observational studies	Reviews, editorials, letters, book chapters, conference abstracts, case reports, and case series with <6 patients
Follow-up	Minimum post-RT follow-up of 1 y	Follow-up duration <1 y

MLUT, modified lower urinary tract; RT, renal transplantation.

This review focused on post-transplant outcomes in adults with MLUT. Mixed adult-pediatric cohorts were retained only when excluding them would have removed a substantial portion of the available evidence and where the study remained relevant to adult transplant practice.

Study Selection

Two investigators (D.S.S. and E.A.) independently screened titles and abstracts for potential eligibility. Full texts of potentially eligible studies were then assessed against the prespecified inclusion and exclusion criteria. Disagreements were resolved via consensus, and a planned third review was not necessary. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram for study selection is shown in Figure 1.

FIGURE 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram. EMBASE, Excerpta Medica dataBASE; MEDLINE, Medical Literature Analysis and Retrieval System Online.

Data Extraction

Data were extracted using a predesigned spreadsheet. Extracted variables included study characteristics such as author, year, country, recruitment period, sex, mean age, live donor transplant (%), immunosuppression used, primary bladder abnormality, and details of reconstructive procedure(s), which are reported in Tables 2 and 3. Outcome data extracted included GS, patient survival, urinary tract infections (UTIs), urosepsis or pyelonephritis, ureteric complications, need for posttransplant urological intervention, and continence outcomes in patients with continent reservoirs. Where studies included mixed adult-pediatric cohorts but presented only pooled results, data were extracted at the study level and interpreted as mixed-cohort evidence.

TABLE 2.

Characteristics of included studies

Study (country)	Study design/comparator	Sample size (MLUT)	Sample size (comparator)	Recipient age (MLUT)	Recipient sex (male%)	Living donor (MLUT %)	Follow-up, mo
Sagalowsky 198912 (United States)	Retrospective case series; no comparator	8 (10 RT)	NA	25 (13–41), mean (range)	5 (62.5)	50	24 (13–42)
Gruessner 199013 (United States)	Retrospective case series; no comparator	16 (19 RT)	NA	24.8 (9–47), mean (range)	7 (44)	50	NR
Cairns 1991 14United Kingdom)	Retrospective cohort: control group reported	62 (69 RT)	157a	NR	34 (54.8)	NR	60
Griffin 199415 (United Kingdom)	Retrospective case series; no comparator	23 (28 RT)	NA	25 (4–60), mean (range)	18 (78.3)	NR	60
Ross 199416 (United States)	Retrospective case series; no comparator	16 (21 RT)	NA	20 (10–33), mean (range)	16 (100)	71.4	120
Dawahra17 1997 (France)	Retrospective case series; no comparator	9b (1 had reconstruction post-RT)	NA	32.5 (20–48), mean (range)	6 (67)	NR	67 (2–108)
Martin 200118 (Spain)	Retrospective case series; no comparator	7	NA	38.4 (19–57), mean (range)	5 (71.4)	0	48 (8–97)
Nahas 200219 (Brazil)	Retrospective case series; no comparator	24 (25 RT)	NA	27.6 (12–53), mean (range)	15 (62.5)	68	53.2 (6–118)
Surange 200320 (United Kingdom)	Retrospective comparative cohort; conduit vs control	54 (59 RT)	2579	28 (1–63), mean (range)	33 (61)	20.3	55.2 (1–240)
Nahas 200421 (Brazil)	Retrospective case series; no comparator	8	NA	18 (3–30), median (range)	7 (87.5)	NR	50 (4–93)
Rigamonti et al22 2005 (Italy)	Retrospective case series; no comparator	24 (1 lost to follow-up)	255c	14 (1–39), median (range)	13 (58)	4.3	d367.2 (1–193)
Chaykovsaka 200823 (Germany)	Retrospective case series; no comparator	6	NA	40.6 (16–64), mean (range)	5 (83)	33	63.6
Blanco 200924 (Spain)	Retrospective case series; no comparator	6	NA	52 (22–72), mean (range)	2 (33)	NR	56 (20–100)
Kocot 2009 25(Germany)	Retrospective case series; no comparator	18	NA	29.8 (8–63), mean (range)	9 (53)	11.1	89.2 (2–108)
Mahdavi Zafarghandi et al26 2010 (Iran)—EC	Retrospective comparative cohort; EC vs control	16	30	17.93 (7.35), mean (SD)	11 (69)	100	120
Mahdavi Zafarghandi et al26 2010 (Iran)—UC	Retrospective comparative cohort; UC vs control	8	30	11.5 (4.34), mean (SD)	6 (75)	100	120
Slagt et al27 2013 (the Netherlands)	Retrospective comparative cohort; conduit vs control	13 (16 RT)	52	23 (20–45), median (range)	8 (61.5)	77	53 (20–94)
Srinivasan et al9 2016 (United States)	Retrospective cohort: control group reported	21	1652	48.6 (12.8), mean (SD)	12 (57.1)	52.4	48
Fournier 2017 28(France)	Retrospective case series; no comparator	16	NA	37 (21–63), median (range)	8 (50)	12.5	171 (30–328)d
Desai 201829 (India)	Retrospective case series; no comparator	14	NA	22.5 (9.70), mean (SD)	12 (85.7)	100	36
Jayanth et al2 2019 (India)	Retrospective cohort; control group reported	31 (32 RT)	32	24 (12–45), median (range)	25 (78.1)	93.8	36
Zahran 2021 30(Egypt)—EC	Retrospective comparative cohort; EC vs control	23	122	21 (12–25), median (IQR)	17 (73.9)	100	37 (12–100)
Zahran 202130 (Egypt)—UC	Retrospective comparative cohort; UC vs control	11	122	13 (9–20), median (IQR)	10 (90.9)	100	33 (13–187)
Flegar 202431 (Germany)	Retrospective case series; no comparator (multicenter)	37 (30 had pre-RT reconstruction)	NA	43 (10–68), mean (range)	21 (56.8)	16.2	120 (0–444)
Ekin 202632 (Turkey)	Retrospective case series; no comparator	15	NA	25.07 (6.82), mean (SD)	6 (40)	93.3	98.9 (57.4)

^aOnly conduit recipients relevant to the review were extracted.

^bDenominator differs from total MLUT cohort because not all variables were reported for all recipients.

^cCompared with the center’s overall renal transplant population rather than a matched control cohort.

^dThe article text and abstract differ in values; main article outcomes have been used.

EC, enterocystoplasty; IQR, interquartile range; MLUT, modified lower urinary tract; NA, not applicable; NR, not reported; RT, renal transplantation; UC, ureterocystoplasty.

TABLE 3.

Underlying lower urinary tract abnormalities and reconstructive strategies in included studies

Study (country)	Underlying bladder abnormality/indication	Reconstructive strategy	Timing of reconstruction	Ureteric anastomotic technique
Sagalowsky12 1989 (United States)	Neurogenic bladder, PUVs, dysfunctional voiding, congenital atresia, acquired bladder contracture	Augmentation cystoplasty; ileal conduit	Mixed/not clearly reported	Extravesical (4), intravesical (1)
Gruessner13 1990	Neurogenic bladder, VUR, urinary tract abnormalities	Ileal and colonic conduits	2 wk before transplant in 13/16 patients	Interrupted full thickness 4/0 absorbable suture, 2 layers for colonic, and 1 layer for ileal conduits
Cairns14 1991 (United Kingdom)	Neuropathic bladder, tuberculosis, cyclophosphamide toxicity, rhabdomyosarcoma, prune belly syndrome, bladder neck obstruction	Ileal conduit; isolated rectal bladder with colostomy	Pretransplant	NR
Griffin15 1994 (United Kingdom)	Neurogenic bladder, tuberculosis, PUV, prune belly syndrome, ectopia vesicae	Mixed reconstructive cohort, including cecocystoplasty, clam cystoplasty, ileal conduit, ileocystoplasty, modified Mitrofanoff, and bladder neck incision with ISC	Mixed/not clearly reported	NR
Ross16 1994 (United States)	PUV/valve bladder	Urinary diversion; ureteric reimplantation	Mixed/not clearly reported	NR
Dawahra17 1997 (France)	Neurogenic bladder, sacral agenesis, bladder exstrophy	Supravesical diversion (Kock pouch or Mainz pouch)	Pretransplant	Anastomosis in anterior tenia coli and not in cecum with submucosal tunnel
Martin18 2001 (Spain)	Tuberculosis, neurogenic bladder, cyclophosphamide toxicity, hyperreflexic bladder	Ileal cystoplasty; ileocecal cystoplasty	Pretransplant	Ureters reimplanted into bowel segment of AC using submucosal tunnel as antireflux extravesical approach
Nahas19 2002 (Brazil)	Neurogenic bladder/detrusor hyperreflexia, tuberculosis, VUR, PUV, interstitial cystitis	Augmentation cystoplasty	Mainly pretransplant; some posttransplant	Lich-Gregoir (15), no antireflux technique (1)
Surange20 2003 (United Kingdom)	Spina bifida, neurogenic/neuropathic bladder, bladder exstrophy, PUV, VUR, prune belly syndrome, cloacal abnormality, tuberculosis, miscellaneous complex abnormalities	Ileal conduit	Pretransplant	Continuous tension-free anastomosis using 4/0 absorbable suture
Nahas21 2004 (Brazil)	Neurogenic bladder, PUV, VUR	UC	Pretransplant	NR
Rigamonti et al22 2005 (Italy)	PUV, neurogenic bladder, urethral hypoplasia, bladder exstrophy	Augmentation cystoplasty, urinary diversion	Pretransplant	Lich-Gregoir (13), Politano (2), refluxing (1)
Chaykovsaka23 2008 (Germany)	Neurogenic bladder, VUR.	Urinary conduits using ileum/colon	Pretransplant	Ureteroureterostomy between RT and native ureter. Native ureter anastomosed to ileum with Bricker technique
Blanco24 2009 (Spain)	Tuberculosis, spina bifida, bladder exstrophy	Augmentation cystoplasty	Pretransplant	Ureteroureterostomy with native ureter (5), ureteroenteric anastomosis (1)
Kocot25 2009 (Germany)	Myelomeningocele, PUV, bladder TCC, upper tract TCC, tuberculosis, interstitial cystitis	Ileocecal pouch; sigmoid neobladder; left colonic pouch	Pretransplant	Mathisena or Goodwinb et al techniques (antireflux)
Mahdavi Zafarghandi et al26 2010 (Iran)—EC	Neurogenic bladder, tuberculosis, PUV	EC	Pretransplant	NR
Mahdavi Zafarghandi et al26 2010 (Iran)—UC		UC
Slagt et al27 2013 (the Netherlands)	Reflux nephropathy, neurogenic bladder, recurrent infections, tuberculosis	Mixed reconstructive cohort, including augmentation cystoplasty, Mitrofanoff, isolated sigmoid reservoir, Bricker conduit, Indiana pouch, and native ureter implantation	Pretransplant/mixed	Bricker/Indiana pouch: End to side to terminal ileum/taeniae of cecum Mitrofanoff: Intravesical/extravesical (surgeon preference)
Srinivasan et al9 2016 (United States)	Not specified in detail	Orthotopic neobladder; EC; bladder reconstruction unspecified; cutaneous ureterostomy; Mitrofanoff	Mixed/not clearly reported	Lich-Gregoir
Fournier28 2017 (France)	TCC, bladder exstrophy, neurogenic bladder dysfunction	Continent urinary diversion (Mainz pouch, Kock pouch, neobladder)	Pretransplant	NR
Desai29 2018 (India)	Small-capacity/poor-compliance bladder, high PVR, rectal cancer	Gastrocystoplasty with Mitrofanoff; UC; ileocystoplasty with Mitrofanoff; ileal conduit; ISC	Mixed/tailored pretransplant optimization	Lich-Gregoir
Jayanth et al2 2019 (India)	Neurogenic bladder, PUV, urethral stricture, dysfunctional voiding, prior cystectomy, BOO, VUR	Augmentation cystoplasty; ileal conduit; bladder neck incision; substitution urethroplasty; nephrectomy for VUR	Mixed/tailored pretransplant optimization	Roy Calne’s extravesical (7), Goodwin et alb (2), Politano (1), ureteroureterostomy (1)
Zahran30 2021 (Egypt)—EC	PUV, neuropathic bladder, bilharzial contracted bladder, VUR	EC	Pretransplant	Antireflux (12), refluxing (22)
Zahran30 2021 (Egypt)—UC		UC
Flegar31 2024 (Germany)	VUR, spina bifida, and other complex lower urinary tract abnormalities	Ileal conduit; augmented bladder; appendicovesicostomy; ureterocutaneostomy	Mixed	NR
Ekin32 2026 (Turkey)	Neurogenic bladder, PUV, bladder exstrophy	Augmentation cystoplasty	Pretransplant	NR

^aMathisen W. A new method for ureterointestinal anastomosis. Surg Gynecol Obstet. 1953;96:255.

^bGoodwin WE, Harris AP, Kaufmann JJ, et al. Open, transcolonic ureterointestinal anastomosis; a new approach. Surg Gynecol Obstet. 1953;97:295.

AC, augmentation cystoplasty; BOO, bladder outlet obstruction; EC, enterocystoplasty; ISC, intermittent self-catheterization; NR, not reported; PUV, posterior urethral valve; PVR, postvoid residual; RT, renal transplantation; TCC, transitional cell carcinoma; UC, ureterocystoplasty; VUR, vesicoureteral reflux.

Outcomes

The primary outcomes were as follows:

• GS at 1 and 5 y.

• Patient survival at 1 and 5 y.

The secondary outcomes were as follows:

• UTIs and recurrent UTIs (rUTIs).

• Urosepsis/pyelonephritis.

• Ureteric complications (ureteric leak/strictures).

• Posttransplant radiological/urological intervention.

• Continence outcomes in continent reservoirs.

Assessment of Methodological Quality

Given the heterogeneity of study designs, we used the Methodological Index for Non-Randomized Studies instrument to assess methodological quality and risk of bias. Noncomparative studies were scored using the 8-item scale (maximum score 16), whereas for comparative series we used the full 12-item scale (maximum score 24). Each item was scored 0 (not reported), 1 (reported but inadequate), or 2 (reported and adequate).³³ Two investigators (D.S.S. and E.A.) performed this assessment independently. There were no discrepancies between the 2 reviewers.

Data Synthesis

Because of anticipated clinical and methodological heterogeneity, a narrative synthesis was planned as the primary analytical method. Heterogeneity was expected in underlying pathology, type and timing of reconstruction, comparator group selection, follow-up duration, and outcome definitions. For graft and patient survival data, findings were summarized descriptively and visually compared across studies. We did not numerically aggregate scores, consistent with methodological recommendations. No attempt was made to input missing data or create survival curves.

RESULTS

Study Selection and Characteristics

The search revealed 3021 articles. After removing duplicates (n = 1352), 1669 articles were screened. Following full-text screening of 96 articles, 24 studies were included. The study selection process is summarized in Figure 1.

The included studies spanned >4 decades, from 1970 to 2026, and comprised 486 RT recipients with MLUT. All studies except 1 were single-center case series, and only a minority included a comparator cohort of recipients with unmodified or apparently normal lower urinary tract anatomy performed over the same period. Follow-up duration was variable, ranging from 36 to 444 mo.

The sex of the recipients for the MLUT group revealed a male preponderance. Only 15 studies provided information on donor characteristics, with the proportion of live donor transplants ranging from 12.5% to 100% in the series reported. Immunosuppression regimens were heterogeneous and era-specific, ranging from cyclosporine/azathioprine in the early studies to tacrolimus/mycophenolate mofetil in the contemporary series.

The underlying pathology and type of reconstruction were highly heterogeneous. The most reported underlying diagnoses were neurogenic bladder and posterior urethral valves, followed by bladder exstrophy, prune belly syndrome, tuberculosis, and other inflammatory or malignant conditions. Reconstructive strategies included augmentation cystoplasty (AC), continent catheterizable channels, ileal conduits, continent reservoirs, and orthotopic neobladders (Table 3). Reporting of pretransplant bladder assessment, including bladder capacity, compliance, and formal urodynamics (UDS), was inconsistent across the literature.

Most reconstructions were performed pretransplant, although several series reported mixed timings, and a small minority of patients underwent reconstruction posttransplant. Reporting of ureteric implantation techniques was inconsistent. Where described, both refluxing and antireflux techniques were used, precluding conclusions regarding any association with graft or urological outcomes (Table 3).

Survival Outcomes

Graft Survival

Survival outcomes were reported inconsistently across studies, with incomplete reporting at fixed timepoints and variable availability of comparator data. Moreover, although most studies used transplants conducted in patients with normal anatomy at the same time as a comparator, the population was not matched. Reported 1-y GS in MLUT cohorts ranged from 85.1% to 100% in comparative series, while 5-y GS ranged from 63% to 85.2% (Table 4). By comparison, reported 1-y GS in control cohorts ranged from 77.1% to 100%, and 5-y GS from 69.6% to 94.1%.

TABLE 4.

Reported graft and patient survival outcomes in included studies

Study	1-y GS, MLUT (%)	1-y GS, control (%)	5-y GS, MLUT (%)	5-y GS, control (%)	1-y PS, MLUT (%)	1-y PS, control (%)	5-y PS, MLUT (%)	5-y PS, control (%)	Notes
Sagalowsky12 1989	NR	NA	NR	NA	NR	NA	NR	NA	Cumulative GS 70% at mean follow-up 24 mo (range, 13–42 mo)
Gruessner13 1990	100	NA	56	NA	NR	NA	NR	NA	Mean GS 110.5 mo (13–291 mo)
Cairns14 1991a	90	85	71	73	NR	NR	NR	NR	Data extracted for urinary conduit subgroup only
Griffin15 1994	NR	NR	70	70	NR	NR	82	90	–
Ross16 1994b	NR	NR	59	NR	NR	NR	NR	NR	GS at 2 y: 70%
Dawahra17 1997c	NR	NA	77.8	NA	NR	NA	100	NA	Data are reported at mean follow-up 67 mo (range, 2–108 mo)
Martin17 2001d	NR	NA	100	NA	NR	NA	NR	NA	Data are reported at mean follow-up 48 mo (range, 8–97 mo)
Nahas19 2002	96	NA	78	NA	96	NA	86	NA	–
Surange20 2003	89.7	83.9	63	69.6	94.9	95	83.2	87.6	–
Nahas21 2004e	NR	NA	100	NA	NR	NA	NR	NA	Data are reported at mean follow-up 50 mo (range, 4–93 mo)
Rigamonti et al22 2005—AC	94.1	87.4	80.7	77.1	NR	NA	NR	NA	Comparator shared with AC/UD subgroups
Rigamonti et al22 2005—UD	100		83.3
Chaykovsaka23 2008 (Germany)	100	NA	83.3	NA	100	NA	100	NA
Blanco24 2009f	NR	NA	NR	NA	NR	NA	NR	NA	50% GS at mean follow-up 56 mo (range, 20–100 mo)
Mahdavi Zafarghandi et al26 2010—EC	94	100	82	92	94	100	94	96	Comparator shared with UC/EC subgroups
Mahdavi Zafarghandi et al26 2010—UC	100		80		100		80
Slagt et al27 2013	100	100	69	79	100	100	92	90	Death and retransplantation censored statistics
Srinivasan et al9 2016	85.7	92.5	66.6	77.3	91.2	96.2	75.2	84.3	–
Fournier28 2017	100	NA	87.5	NA	100	NA	100	NA	–
Desai29 2018g	100	NA	NR	NA	NR	NA	NR	NA	GS 100% at 3 y
Zahran30 2021	NR	NR	85.2	94.1	NR	NR	NR	NR	5-y GS for MLUT overall; EC 95.7%, UC 90.9% reported separately
Flegar31 2024	88.7	NA	79.3	NA	96.7	NA	89	NA	–
Ekin32 2026 (Turkey)	100	NA	90.9	NA	NR	NA	NR	NA

^aData extracted for ileal conduit recipients only.

^bReported GS at 2 y only (MLUT 70%, control 59%).

^cReported at mean follow-up of 67 mo (range, 2–108 mo).

^dReported at mean follow-up of 48 mo (range, 8–97 mo).

^eReported at mean follow-up of 50 mo (range, 4–93 mo).

^fReported at mean follow-up of 56 mo (range, 20–100 mo).

^gGS reported at 3 y only.

AC, augmentation cystoplasty; EC, enterocystoplasty; GS, graft survival; MLUT, modified lower urinary tract; NA, Not applicable; NR, not reported; PS, patient survival; UC, ureterocystoplasty; UD, urinary diversion.

Across comparative series, 1-y GS appeared broadly similar between MLUT and control cohorts. In contrast, although 5-y GS tended to be lower in several MLUT cohorts, this finding was not consistent across studies and should be interpreted cautiously given the small comparative datasets (Figure 2). This pattern has been depicted in Figure 2, which presents reported comparative 1- and 5-y GS at the study level. This trend was not observed in the study by Rigamonti et al,²² where 1- and 5-y GS were lower in the control group.

FIGURE 2.

Comparative study-level graft survival at 1 and 5 y in recipients with MLUTs and comparator cohorts. Only studies reporting comparative data at the relevant time point are shown. Comparator cohorts were not matched in most studies. Furthermore, comparator cohorts frequently represented the center’s overall transplant population rather than disease-specific matched controls. AC, augmentation cystoplasty; EC, enterocystoplasty; MLUT, modified lower urinary tract; NR, not reported; UD, urinary diversion.

Several noncomparative series also reported acceptable medium-term GS in selected reconstructed cohorts, including 5-y GS of 77.8% to 100%. However, these findings should be interpreted with caution given the absence of a comparator group and substantial variation in pathology and reconstructive approach.

Adjusted comparative time-to-event analyses were reported by a small number of studies. Mahdavi Zafarghandi et al²⁶ observed no statistical difference in patients with enterocystoplasty (hazard ratio [HR], 1.036; P = 0.963) and ureterocystoplasty (HR, 3.131; P = 0.357) versus normal bladders, whereas Srinivasan et al⁹ noted increased graft failure in patients with previous bladder surgery (HR, 3.57; 95% confidence interval, 1.06-12.1; P = 0.04)]. Jayanth et al² also found median GS in AC (81 mo [interquartile range, 56-106 mo]) to be shorter than in patients with normal bladders (116 mo [interquartile range, 105-127 mo]).

Limited comparisons between reconstructive techniques produced inconsistent findings and do not permit conclusions regarding the superiority of 1 reconstructive approach.

Patient Survival

Patient survival was less frequently reported than GS. Where comparative data were available, 1-y patient survival was generally high in both MLUT and control cohorts, whereas reported 5-y patient survival ranged from 75.2% to 94% in MLUT cohorts and from 84.3% to 100% in control cohorts (Table 4). Overall, comparative patient survival appeared broadly similar, although several studies suggested numerically lower longer-term survival in MLUT cohorts.

Only 2 studies reported adjusted comparative analyses for patient survival, and neither demonstrated a statistically significant difference between cohorts (Figure 3). As with GS, the limited number of studies and inconsistent reporting precluded quantitative synthesis.^9,26

FIGURE 3.

Comparative study-level patient survival at 1 and 5 y in recipients with MLUTs and comparator cohorts. Only studies reporting comparative data at the relevant time point are shown. Comparator cohorts were not matched in most studies. Furthermore, comparator cohorts frequently represented the center’s overall transplant population rather than disease-specific matched controls. EC, enterocystoplasty; MLUT, modified lower urinary tract; NR, not reported; UC, ureterocystoplasty.

Urological Complications

The reporting of urological complications was heterogeneous and often incomplete. Nevertheless, rUTIs emerged as the most consistently reported complication and appeared common in MLUT recipients (Table 5). Only Srinivasan et al⁹ reported a comparison with control (55% versus 10.8%). Across the broader literature, episodes of urosepsis, pyelonephritis, and ureteric complications were variably described. Generally, they were noted to be more frequent in reconstructed lower urinary tracts than in standard RT recipients.

TABLE 5.

Reported urological complications and continence outcomes in included studies

Study	UTI	Urosepsis/pyelonephritis	Structural urological complications	Urological reintervention	Continence outcome	Notes
Sagalowsky12 1989	NR	6 patients (8 episodes)	NR	2 interventions	3/5 continent	↑Bladder capacity ↓Residual urine ↓Bladder pressures
Gruessner13 1990	12 had rUTI	4 deaths because of urosepsis	1 urinary fistula	Ureteric reimplantation (1)	NR	Calculi (2)
Cairns14 1991l	NR	NR	3 urine leaks	Ureteric reimplantation (2)	NR	Loop calculus (1)
Griffin15 1994	NR	NR	NR	5 interventionsa	16/17 continenta	–
Ross16 1994	19% had overall urological complications	NR	NR	NR	NR	Overall complication burden reported rather than specific complication categories
Dawahra17 1997	3 UTI episodes in 1 patient	NR	NR	1 interventionb	8/8 continent	–
Martin18 2001	4 patients had recurrent UTI	2 patients (<1 episode/year)	1 urinary fistula	Ureteric reimplantation (1)	6/7 continent	Infectious burden described indirectly
Nahas19 2002	8 patients with UTI	8 patients (14 episodes)	VUR (3) who had refluxing anastomoses	2 interventionsc	14/24 continentd	↑Bladder capacity ↑Bladder compliance
Surange20 2003	Single UTI (65%); >1 episode (50%)	NR	Urine leak (7); stricture (4); recurrent stomal stenosis (1)	Ureteric reimplantation (7), PCN (1)	NA	Loss of graft in 1 patient (distal ureteric stenosis leading to staghorn calculus); stent migration (1) needing nephroscopic retrieval
Nahas21 2004	3 patients with recurrent UTI	1 episode	VUR (1)	1 interventione	7/8 continent	↑Bladder capacity ↓Bladder pressures
Rigamonti et al22 2005	rUTI: 2/16 (AC), 3/8 (UD)	2/16 in AC group	1 urinary fistula, 1 ureteric obstruction	2 patients needed a stent	NA	Stones: AC (3), UD (1)
Chaykovsaka23 2008 (Germany)	NR	3 had recurrent admissions	1 fistula causing obstruction	0	NA	–
Blanco24 2009	2 patients with recurrent UTI (mean: 7 UTIs)	1 patient	NR	1 interventionf	4/6 continent	Stent migration (2) needing antegrade removal
Kocot25 2009	NR	5 patients with recurring pyelonephritis	No strictures	15 interventions	17/17 continent	–
Mahdavi Zafarghandi et al26 2010—EC	EC had higher UTI and urosepsis than UC	29 episodesg	NR	NR	NR	Control group reported 2 episodes
Mahdavi Zafarghandi et al26 2010—UC		6 episodesg
Slagt et al27 2013	9 patients with UTI	NR	NR	8/13 interventionsh	NR	Comparator reintervention data reported: 14/52 Similar rates of PCN as intervention
Srinivasan et al9 2016	rUTI: MLUT 52.3% vs control 10.7%	0/20 vs 2/1652	0/20 vs 32/1652i	NR	NR	Overall urological complications 52.3% vs 12.8%j
Fournier28 2017	NR	8 patients	1 complication	14 interventionsk	NR
Desai29 2018	8 patients with UTI	6 patients	0 urinary leak or stones	NR	3/10 continent	–
Zahran30 2021—EC	NR	17 patients (33 episodes)	0	NR	6/23 continent	Control group: 53 episodes; 2 ureteric complications
Zahran30 2021—UC	NR	5 patients (14 episodes)	0	NR	4/11 continent
Flegar31 2024	NR	NR	NR	NR	NR	–
Ekin32 2026 (Turkey)	NR	8 patients (15 episodes)	0	NR	NA	10/15 had Mitrofanoff

^aConversion of clam cystoplasty to cecocystoplasty (n = 1), artificial urinary sphincter insertion (n = 3), and conversion of cecocystoplasty to conduit (n = 1).

^bPCN (n = 2) and ureteric reimplantation (n = 1).

^cPercutaneous Acucise catheter (n = 1) and ureteric reimplantation (n = 1).

^dIncludes patients voiding spontaneously or with Valsalva without the need for ISC.

^eReintervention for reflux.

^f PCN for fistula.

^gNumber of episodes rather than number of affected patients.

^hPCN (n = 5): all these patients later underwent surgical reintervention (ureteric reimplantation; 3), new anastomosis (1), graft pyelum connected to conduit (1), ureteric surgery (n = 3), percutaneous nephrolithotomy (1), and revision of anastomosis (1).

ⁱIncludes ureteric strictures and/or leaks as reported.

^jReported as overall urological complications in the source study.

^kIncludes stomal dilation, anastomotic dilation, valve revision, stone treatment, and nephrectomy.

^lConduit-specific data only.

AC, augmentation cystoplasty; EC, enterocystoplasty; ISC, intermittent self-catheterization; MLUT, modified lower urinary tract; NA, not applicable; NR, not reported; PCN, percutaneous nephrostomy; rUTI, recurrent urinary tract infection; UC, ureterocystoplasty; UD, urinary diversion; UTI, urinary tract infection; VUR, vesicoureteral reflux.

Posttransplant surgical interventions were variably reported. Procedures primarily included insertion of percutaneous nephrostomy, ureteric reimplantation followed by insertion of artificial urinary sphincter, and revision of augmented reservoirs (Table 5).

Reported comparative data between modified bladder and controls included:

• Slagt et al²⁷—MLUT 61.53% versus controls 26.9%.

• Srinivasan et al⁹ observed an almost 4 times higher risk of urological complications in the bladder surgery cohort (52.3%) than in patients with normal bladder (12.3%).

Continence

Approximately two-thirds of recipients across all studies with continent reservoirs remained continent posttransplant either spontaneously or with Valsalva-assisted voiding, while the remainder were managed with intermittent self-catheterization.

Methodological Quality and Risk of Bias Assessment

Overall methodological quality was modest. Using the Methodological Index for Non-Randomized Studies instrument, most studies scored ≥2 for a clearly stated aim and adequate follow-up, but scored poorly for prospective data collection, a priori calculation of sample size, and blinded assessment of outcomes. Among comparative studies, baseline equivalence and the nature of contemporary controls were variably reported, limiting interpretability of between-group comparisons. The heat map of risk of bias assessment is detailed in Figure 4.

FIGURE 4.

Risk of bias assessment, methodological quality assessment of included studies using the MINORS. Green indicates adequate reporting (score 2), yellow indicates inadequate or unclear reporting (score 1), and red indicates absence of reporting (score 0). A, Noncomparative studies were assessed using the 8-item MINORS instrument, whereas (B) comparative studies were assessed using the 12 MINORS domains. MINORS, Methodological Index for Non-Randomized Studies. LOF, Loss of follow-up.

DISCUSSION

This systematic review synthesizes the contemporary adult-focused evidence on kidney transplantation recipients with MLUT. Overall, literature is sparse, heterogeneous, and predominantly retrospective, with most studies limited to single centers and only a minority including a comparator cohort. Within these limitations, 3 principal observations were made. Firstly, reported 1-y GS in recipients with MLUT appeared broadly similar to that of comparator recipients in comparative studies. Secondly, 5-y GS was often lower in MLUT cohorts; however, this was not uniform across the literature, and the comparative datasets were small to draw definite conclusions. Finally, urological morbidity, especially rUTIs and the need for posttransplant urological intervention, was higher in recipients with MLUT than those with normal bladders.

Survival Outcomes: Early Equivalence, Late Divergence

The most consistent signal from the comparative data was a difference between early and longer-term graft outcomes. Across studies reporting fixed timepoint survival, 1-y GS was similar across groups; however, 5-y GS was lower in MLUT compared with comparator groups. Although these findings should not be overinterpreted, they may suggest that transplantation into reconstructed lower urinary tracts is not inferior in terms of early graft outcomes in appropriately selected recipients, but longer-term outcomes may be lower than in patients with normal anatomy.

These conclusions are in part supported by limited comparative data from a small number of studies. Jayanth et al² reported lower median GS in patients with augmented bladders (81 versus 116 mo). Similar directional trends were observed by Mahdavi Zafarghandi et al²⁶ and Srinivasan et al⁹; however, their results did not reach statistical significance. Taken together from these studies, the defensible interpretation is that early graft outcomes may be acceptable in carefully selected MLUT recipients, whereas longer-term outcomes may be less favorable.

Reporting of patient survival was less consistent, and the comparative evidence base was weaker. However, when available, it mirrored the findings of GS, with 1-y PS comparable in patients with MLUT and normal lower urinary tracts, while long-term PS was lower in the MLUT cohorts. The small number of studies, wide confidence intervals, and inconsistent reporting prevent drawing robust conclusions. These findings concur with a recent review by Haberal et al⁵ in which similar PS between children with lower urinary tract abnormalities and those with normal lower urinary tracts was demonstrated.³⁴

Urological Morbidity: The Dominant Burden

Examining the studies revealed that urological morbidity was higher in the cohort of recipients who were transplanted onto a modified bladder. Across the included studies, rUTI was the most frequently reported complication, with several series reporting higher rates after transplantation onto reconstructed lower urinary tracts. Although direct comparative evidence was limited, the available studies suggested that MLUT recipients experience a greater burden of postoperative UTI and require more urological interventions.³⁵

This matters for 2 reasons. Firstly, recurrent infection, pyelonephritis, outlet dysfunction, reservoir-related complications, and the need for repeated procedures may impair quality of life even where GS is preserved. Secondly, although the current evidence does not allow a direct causal chain to be demonstrated, repeated urological morbidity provides a plausible mechanism by which longer-term graft outcomes may be adversely affected.

The literature on repeat intervention was heterogeneous, but where reported, procedures such as percutaneous nephrostomy, ureteric reimplantation, revision of augmentation, and management of reservoir or stoma complications were not uncommon. Continence outcomes were infrequently reported, but the limited available data suggest that a proportion of patients continue to require intermittent self-catheterization or Valsalva-assisted emptying after transplantation.

Physiological Considerations

The observed pattern of preserved early graft outcomes despite greater longer-term morbidity is biologically plausible, as reconstructed reservoirs are not equivalent to a native compliant bladder. AC may improve capacity and reduce storage pressures but is well known to be a risk factor for long-term sequelae such as bacteriuria, mucus production, stone formation, and metabolic consequences.³⁴ Similarly, urinary diversion (continent and incontinent) achieves drainage and protects upper tracts, but is often associated with stomal, anastomotic, and reservoir-related complications.^1,35

Most studies did not report on urodynamic findings; hence, the present review cannot determine which pretransplant parameters best correlated with posttransplant success, nor can it establish superiority of 1 reconstructive procedure over the other.^36–39

Clinical Implications and Optimization Framework

Patients with lower urinary tract malformations, particularly the pediatric cohort, have historically faced difficulty in receiving transplantation owing to fears of increased graft loss and long-term complications.⁴ Our study reveals that patients with modified bladders can be safely implanted owing to acceptable graft and patient survival outcomes (Figure 5). However, it does raise concerns regarding the substantial urological morbidity and possibly less favorable longer-term graft outcomes in some cohorts. This aligns with the well-established physiological concerns of decline in function, reflux, hydronephrosis, metabolic disturbances, etc.^35,40 It is interesting to note that despite the changes in immunosuppression regimes and better pretransplant assessment, the morbidity profile has remained rather consistent >4 decades, underlining the possible role of anatomical alteration dominating over other factors in determining long-term outcomes.

FIGURE 5.

Proposed pretransplant optimization framework; proposed pragmatic framework for evaluation and optimization of the modified lower urinary tract before renal transplantation. The algorithm summarizes key considerations including lower urinary tract assessment, identification of high-pressure or poorly compliant reservoirs, bladder emptying strategies, continence status, reconstruction options, and peritransplant planning. The framework is based on the findings of the current review together with contemporary reconstructive and transplant urological principles. It is intended to support multidisciplinary decision-making rather than serve as a formal guideline. AC, augmentation cystoplasty; CCCs, continent catheterizable channels; CISC, clean intermittent self-catheterization; CT, computed tomography; UDS, urodynamics; VCUG, video cystourethrography; VUDS, video urodynamics.

These findings reinforce the following lessons, which can possibly guide transplant teams:

• Role of pretransplant evaluation

A comprehensive workup, including invasive/video UDS, where clinically indicated, should be strongly considered in this patient cohort to identify structural malformations and make shared decision-making regarding pretransplant optimization.

An individualized approach is essential to identify the right procedure for the right patient depending on UDS results, ability and willingness to perform clean intermittent self-catheterization, and previous surgical history.

• Patient counseling

These recipients need to be counseled about possible increased long-term risk of graft dysfunction and greater urological morbidity in dedicated appointments with specialist teams.

• Surgical planning

It is essential that a well-formulated surgical plan is agreed upon in advance after discussion with a multidisciplinary team to deliver optimal outcomes, especially if the operation is conducted with the donor organ from deceased recipients. It makes a case for centralizing these cases to higher-volume centers with access to transplant, reconstructive, and functional urology expertise.

• Long-term follow-up

This cohort of patients may benefit from structured long-term surveillance given the higher burden of urological complications. Early recognition and management may attenuate graft injury.

Based on the available literature and established reconstructive principles, we propose an expert-informed pragmatic framework for pretransplant assessment and optimization (Figure 5). Key components include structured clinical evaluation, targeted imaging, urodynamic assessment where indicated, identification of unsafe reservoirs, optimization of bladder emptying, and consideration of augmentation or diversion in selected patients. Given the heterogeneity of the available evidence, this framework should be regarded as a practical decision-support tool rather than a formal guideline. The detailed rationale underpinning the framework is provided in Supplementary Appendix 2 (SDC, https://links.lww.com/TXD/A917).

Limitations

There are several limitations to this review. Primarily, the included evidence base is composed of mostly single-center, retrospective studies with small sample sizes, inconsistent outcome definitions, incomplete reporting of comparator selection, and variable duration of follow-up. The included cohorts were clinically heterogeneous, encompassing different pathologies, reconstructive strategies, and eras of transplantation. Moreover, several studies also included data from pediatric patients without stratification. These limitations precluded us from pooling data across studies and drawing causal inferences. Importantly, the included studies likely represent several distinct clinical populations encompassing congenital anomalies, neurogenic dysfunction, inflammatory disease, and previous reconstructive procedures. Consequently, pooled interpretation should not be taken to imply that outcomes are equivalent across all MLUT subgroups.

Despite these limitations, it is essential to understand the observations noted in this study. To our knowledge, this is the first systematic review specifically synthesizing transplant outcomes in recipients with MLUTs while proposing a pragmatic optimization framework for adult transplant practice. It may assist clinicians in understanding the unique challenges faced by patients and surgeons alike in this cohort of patients, prompting improved care through timely shared decision-making.

Implications for Research

The main research problem is one of scale and standardization. Individual centers are unlikely to accumulate enough cases to produce robust prospective evidence on their own. Progress will therefore require multicenter collaboration with agreed minimum datasets, clearer comparator definitions, and standardized reporting of bladder physiology, reconstructive history, postoperative infection, and reintervention.

At the same time, given the practical difficulty of conducting large comparative studies in this population, a formal Delphi or consensus exercise among transplant and reconstructive urologists may be the most realistic next step toward defining an evidence-informed optimization pathway for adult MLUT candidates.

CONCLUSIONS

RT in carefully selected adults with MLUTs appears feasible, with early graft and patient survival generally comparable to standard recipients. However, urological morbidity remains considerable, and longer-term GS may be less favorable in some populations. Given the small and heterogeneous evidence base, these findings should primarily support careful patient selection, structured lower urinary tract assessment, and development of prospective multicenter studies.