Robotic approach to vesicourethral anastomotic stenosis and resection of remaining prostate after radical prostatectomy

ABSTRACT Objective: To show a total transabdominal robotic approach to an extensive recalcitrant vesicourethral anastomotic stenosis (VUAS) after open radical prostatectomy (ORP) with end-to-end anastomosis. While there is very little literature on the matter and even fewer videos showing the actual surgical view with a step-by-step explanation in complex cases, VUAS robotic transabdominal surgery provides better view and reach, with potentially better continence results, without the need for pubectomy. Methods: A 72-year-old male was submitted to a failed ORP for Gleason 3+4 localized cancer 2 years before, where the wrong plane of dissection left behind prostate remnants and the seminal vesicles, which evolved with a complex stenosis and recurrent episodes of acute urinary retention (AUR) that started two weeks after the first catheter removal. Five endoscopic procedures in total were unsuccessful and AUR reoccurred. A vesico-urethral cystography (VUC) and multiparametric prostate and urethral MRI found the seminal vesicles with prostate remnants, two centimeters urethral stenosis from bladder neck to bulbar urethra and periurethral fibrosis with no evidence of residual tumor. PSA was 1.2 and prostate biopsy showed no tumor on prostate remnant. A transabdominal robotic approach was chosen. Results: Prostate residue, bladder neck and periurethral fibrosis were excised, with healthy mucosa found on both ends. End-to-end anastomosis was successful. Drain and catheter were removed on the 1st and 14th post-operative day, respectively, with good urinary stream. A VUC at 30 days showed a patent bladder neck. Incontinence was 3 pads/day after catheter removal and decreased to 1 pad/day after 180 days. Conclusions: VUAS may reach 15% (1, 2) and endourologic therapies are first-line choices, however, recalcitrant cases require reconstruction (3-6). The most common approach is perineal, with high incontinence rates, reaching >90% (7, 8). The retropubic alternative has better but also discouraging numbers of up to 58% incontinence rates (9). Though with 100% social continence results, the 2021 European guidelines still could not recommend the robotic procedure as standard of care due to evidence limited to anecdotal reports (10-12).

Homemade laparoscopic simulator

Abstract Purpose: To describe a guide for the construction of a laparoscopic training simulator. Methods: Step-by-step description of an inexpensive and easy to assemble homemade laparoscopic training box, capable of simulating the laparoscopic environment in its peculiarities to enable technical skills training. Results: The total cost of the materials for the construction of the simulator was US$ 75.00 (about R$ 250.00 "reais") and it can be reduced to US$ 60.00 if the builder judges that there is no need for internal lighting. The use of real trocars imposes the same challenges as real surgeries regarding positioning, visibility and limitation of movements. Conclusion: The proposed economical and efficient alternative can contribute to the teaching and practice of laparoscopic surgical technique worldwide, benefiting surgeons and patients.

Comparative analysis of late results of cervical esophagogastric anastomosis by manual and mechanical suture in patients submitted to esophageal mucosectomy through advanced megaesophagus / Análise comparativa dos resultados em longo prazo da anastomose esofagogástrica cervical pela sutura manual e mecânica em pacientes submetidos à mucosectomia esofágica por megaesôfago avançado

ABSTRACT Background: Among the anastomoses of the gastrointestinal tract, those of the esophagus are of special interest due to several anatomical or even general peculiarities. Aim: Evaluate retrospectively the results comparing mechanical vs. manual suture at cervical esophagogastric anastomosis in megaesophagus treatment. Methods: Were included 92 patients diagnosed with advanced megaesophagus with clinical conditions to undergo the surgery. All underwent esophageal mucosectomy, performing anastomosis of the esophagus stump with the gastric tube at the cervical level. In order to make this anastomosis, the patients were divided into two groups: group A (n=53) with circular mechanical suture, lateral end; group B (n=39) with manual suture in two sides, lateral end. In the postoperative period, an early evaluation was performed, analyzing local and systemic complications and late (average 5.6 y) analyzing deglutition. Results: Early evaluation: a) dehiscence of esophagogastric anastomosis n=5 (9.4%) in group A vs. n=9 (23.0%) in group B (p=0.0418); b) stenosis of esophagogastric anastomosis n=8 (15.1%) in group A vs. n=15 (38.4%) in group B (p=0.0105.); c) pulmonary infection n=5 (9.4%) in group A vs. n=3 (7.6%) in group B (p=1.0000.); d) pleural effusion n=5 (9.4%) in group A vs. n=6 (15.4%) in group B (p<0.518). Late evaluation showed that 86.4-96% of the patients presented the criteria 4 and 5 from SAEED, expressing effective swallowing mechanisms without showing significant differences among the groups. Conclusion: Cervical esophagogastric anastomosis by means of mechanical suture is more proper than the manual with lower incidence of local complications and, in the long-term evaluation, regular deglutition was acquired in both suture techniques in equal quality.

RESUMO Racional: Das anastomoses do trato gastrointestinal, as do esôfago têm especial interesse devido às varias peculiaridades anatômicas e mesmo sistêmicas. Objetivo: Avaliar retrospectivamente os resultados comparando a sutura mecânica e manual na anastomose esofagogástrica cervical no tratamento do megaesôfago. Métodos: Foram estudados 92 pacientes com diagnóstico de megaesôfago avançado com condições clínicas de serem submetidos à operação. Todos foram submetidos à mucosectomia esofágica, sendo realizada anastomose do coto esofágico com o tubo gástrico no nível cervical. Para a realização desta anastomose, foram divididos em dois grupos: grupo A (n=53) com sutura mecânica circular terminolateral; grupo B (n=39) com sutura manual em dois planos terminolateral. No período pós-operatório foi realizada avaliação precoce, com análise das complicações locais e sistêmicas, e tardia (média 5,6 anos) com análise da deglutição. Resultados: Avaliação precoce: a) deiscência da anastomose esofagogástrica, n=5 (9,4%) no grupo A vs. n=9 (23,0%) no grupo B (p=0.0418); b) estenose da anastomose esofagogástrica n=8 (15,1%) no grupo A vs. n=15 (38,4%) no grupo B (p=0.0105); c) infecção pulmonar n=5 (9,4%) no grupo A vs. n=3 (7,6%) no grupo B (p=1.000); d) derrame pleural n=5 (9,4%) no grupo A vs. n=6 (15,4%) no grupo B (p<0.518). A avaliação tardia demonstrou que 86,4 a 96,0% dos pacientes apresentaram critérios 4 e 5 de SAEED, demonstrando deglutição efetiva e sem diferença significante entre os grupos. Conclusão: A anastomose esofagogástrica pela sutura mecânica é mais adequada que a manual com pequena incidência de complicações locais e, na avaliação em longo prazo, a deglutição demonstrou ser adequada em ambos os grupos e com qualidade semelhante.

Chorioallantoic urothelial tumor avatar. A clinical tool for phenotype-based therapy

Abstract In the muscle invasive bladder cancer (MIBC) standard of care treatment only patients presenting a major pathological tumor response are more likely to show the established modest 5% absolute survival benefit at 5 years after cisplatin-based neoadjuvant chemotherapy (NAC). To overcome the drawbacks of a blind NAC (i.e. late cystectomy with unnecessary NAC adverse events) with potential to survival improvements, preclinical models of urothelial carcinoma have arisen in this generation as a way to pre-determine drug resistance even before therapy is targeted. The implantation of tumor specimens in the chorioallantoic membrane (MCA) of the chicken embryo results in a high-efficiency graft, thus allowing large-scale studies of patient-derived "tumor avatar". This article discusses a novel approach that exploits cancer multidrug resistance to provide personalized phenotype-based therapy utilizing the MIBC NAC dilemma.

Safety and feasibility of radiofrequency ablation for treatment of Bosniak IV renal cysts

ABSTRACT Purpose To describe our initial experience with radiofrequency ablation (RFA) of Bosniak IV renal cysts. Materials and Methods From 2010 to 2014, 154 renal tumor cases were treated with percutaneous thermal ablation, of which 10 cases (6.4%) from nine patients were complex renal cysts and were treated with radiofrequency ablation. Results All complex cysts were classified as Bosniak IV (four women and five men; mean age: 63.6 yrs, range: 33–83 years). One patient had a single kidney. Lesion size ranged from 1.5 to 4.1cm (mean: 2.5cm) and biopsy was performed on four cysts immediately before the procedure, all of which were malignant (two clear cell and two papillary carcinoma). Mean volume reduction of complex cysts was 25% (range: 10–40%). No patients required retreatment with RFA and no immediate or late complications were observed. The follow-up of Bosniak IV cysts had a median of 27 months (interquartile range [IQR], 23 to 38) and no recurrence or significant loss of renal function were observed. Conclusions Mid-term follow-up of the cases in our database suggests that image-guided percutaneous RFA can treat Bosniak IV cysts with very low complication rates and satisfactorily maintain renal function.

Are we following the guidelines on non-muscle invasive bladder cancer?

ABSTRACT Objectives To evaluate the clinical practice of non-muscle invasive bladder cancer (NMIBC) treatment in Brazil in relation to international guidelines: Sociedade Brasileira de Urologia (SBU), European Association of Urology (EAU) and American Urological Association (AUA). Materials and Methods Cross-sectional study using questionnaires about urological practice on treatment of NMIBC during the 32nd Brazilian Congress of Urology. A total of 650 question forms were answered. Results There were 73% of complete answers (total of 476 question forms). In total, 246 urologists (51.68%) lived in the southeast region and 310 (65.13%) treat 1 to 3 cases of NMIBC per month. Low risk cancer: Only 35 urologists (7.5%) apply the single intravesical dose of immediate chemotherapy with Mitomicin C recommended by the above guidelines. Adjuvant therapy with BCG 2 to 4 weeks after TUR is used by 167 participants (35.1%) and 271 urologists (56.9%) use only TUR. High risk tumors: 397 urologists (83.4%) use adjuvant therapy, 375 (78.8%) use BCG 2 to 4 weeks after TUR, of which 306 (64.3%) referred the use for at least one year. Intravesical chemotherapy with Mitomicin C (a controversial recommendation) was used by 22 urologists (4.6%). BCG dose raised a lot of discrepancies. Induction doses of 40, 80 and 120mg were referred by 105 (22%), 193 (40.4%) and 54 (11.3%) respectively. Maintenance doses of 40, 80 and 120mg were referred by 190 (48.7%), 144 (37.0%) and 32 (8.2%) urologists, respectively. Schemes of administration were also varied and the one cited by SWOG protocol was the most used: 142 (29.8%). Conclusion SBU, EAU and AUA guidelines are partially respected by Brazilian urologists, particularly in low risk tumors. In high risk tumors, concordance rates are comparable to international data. Further studies are necessary to fully understand the reasons of such disagreement.

Transanal Minimally Invasive Surgery (TAMIS) to Treat Vesicorectal Fistula: A New Approach

ABSTRACT Purpose: Vesicorectal fistula is one of the most devastating postoperative complications after radical prostatectomy. Definitive treatment is difficult due to morbidity and recurrence. Despite many options, there is not an unanimous accepted approach. This article aimed to report a new minimally invasive approach as an option to reconstructive surgery. Materials and Methods: We report on Transanal Minimally Invasive Surgery (TAMIS) with miniLap devices for instrumentation in a 65 year old patient presenting with vesicorectal fistula after radical prostatectomy. We used Alexis® device for transanal access and 3, 5 and 11 mm triangulated ports for the procedure. The surgical steps were as follows: cystoscopy and implant of guide wire through fistula; patient at jack-knife position; transanal access; Identification of the fistula; dissection; vesical wall closure; injection of fibrin glue in defect; rectal wall closure. Results: The operative time was 240 minutes, with 120 minutes for reconstruction. No perioperative complications or conversion were observed. Hospital stay was two days and catheters were removed at four weeks. No recurrence was observed. Conclusions: This approach has low morbidity and is feasible. The main difficulties consisted in maintaining luminal dilation, instrumental manipulation and suturing.

Validation of Portuguese version of Quality of Erection Questionnaire (QEQ) and comparison to International Index of Erectile Function (IIEF) and RAND 36-Item Health Survey

Purpose To validate the Quality of Erection Questionnaire (QEQ) considering Brazilian social-cultural aspects. Materials and Methods To determine equivalence between the Portuguese and the English QEQ versions, the Portuguese version was back-translated by two professors who are native English speakers. After language equivalence had been determined, urologists considered the QEQ Portuguese version suitable. Men with self-reported erectile dysfunction (ED) and infertile men who had a stable sexual relationship for at least 6 months were invited to answer the QEQ, the International Index of Erectile Function (IIEF) and the RAND 36-Item Health Survey (RAND-36). The questionnaires were presented together and answered without help in a private room. Internal consistency (Cronbach’s α), test-retest reliability (Spearman), convergent validity (Spearman correlation) coefficients and known-groups validity (the ability of the QEQ Portuguese version to differentiate erectile dysfunction severity groups) were assessed. Results We recruited 197 men (167 ED patients and 30 non-ED patients), mean age of 53.3 and median of 55.5 years (23-82 years). The Portuguese version of the QEQ had high internal consistency (Cronbach α=0.93), high stability between test and retest (ICC 0.83, with IC 95%: 0.76-0.88, p<0.001) and Spearman correlation coefficient r=0.82 (p<0.001), which demonstrated the high correlation between the QEQ and IIEF results. The correlations between the QEQ and RAND-36 were significantly low in ED (r=0.20, p=0.01) and non-ED patients (r=0.37, p=0.04). Conclusion The QEQ Portuguese version presented good psychometric properties and high convergent validity in relation to IIEF. The low correlations between the QEQ and the RAND-36, as well as between the IIEF and the RAND-36 indicated IIEF and QEQ specificity, which may have resulted from the patients’ psychological adaptations that minimized the impact of ED on ...

Analysis of the effect of renal excretory system cooling during thermal radiofrequency ablation in an animal model

Objective: Analysis of renal excretory system integrity and efficacy of radiofrequency ablation with and without irrigation with saline at 2 o C (SF2). Materials and Methods: The median third of sixteen kidneys were submitted to radiofrequency (exposition of 1 cm) controlled by intra-surgical ultrasound, with eight minutes cycles and median temperature of 90 o C in eight female pigs. One excretory renal system was cooled with SF2, at a 30ml/min rate, and the other kidney was not. After 14 days of post-operatory, the biggest diameters of the lesions and the radiological aspects of the excretory system were compared by bilateral ascending pyelogram and the animals were sacrificed in order to perform histological analysis. Results: There were no significant differences between the diameters of the kidney lesions whether or not exposed to cooling of the excretory system. Median diameter of the cooled kidneys and not cooled kidneys were respectively (in mm): anteroposterior: 11.46 vs. 12.5 (p = 0.23); longitudinal: 17.94 vs. 18.84 (p = 0.62); depth: 11.38 vs. 12.25 (p = 0.47). There was no lesion of the excretory system or signs of leakage of contrast media or hydronephrosis at ascending pyelogram. Conclusion: Cooling of excretory system during radiofrequency ablation does not significantly alter generated coagulation necrosis or affect the integrity of the excretory system in the studied model. .

Atualização da classificação e tratamento das lesões renais complexas / Update in the classification and treatment of complex renal injuries

A reunião de revista "Telemedicina Baseada em Evidência - Cirurgia do Trauma e Emergência" (TBE-CiTE) realizou uma revisão crítica da literatura e selecionou três artigos atuais sobre o tratamento do trauma renaldefinido como graus III a V pela classificação da Associação Americana de Cirurgia do Trauma (AAST). O primeiro trabalho propõe subestratificação da lesão renal AAST grau IV em 4a (baixo risco) e 4b (alto risco). O segundo trabalho revisa o atual sistema de classificação de lesão renal AASTpara incluir lesões vasculares segmentares e estabelecer uma definição mais detalhada dos graus IV e V. O último artigo analisa a angiografia diagnóstica e angioembolização na fase aguda do trauma renal utilizando dados americanos. A reunião de revista TBE-CiTE elaborou as conclusões e recomendações para o tratamento do trauma renal de alto grau.

The "Evidence-Based Telemedicine - Trauma and Acute Care Surgery" (EBT-TACS) Journal Club performed a critical review of the literature and selected three up-to-date articles on the management of renal trauma defined as American Association for the Surgery of Trauma (AAST) injury grade III-V. The first paper was the proposal for the AAST grade 4renal injury substratification into grades 4a (Low Risk) and 4b (High Risk). The second paper was a revision of the current AAST renal injury grading system, expanding to include segmental vascular injuries and to establish a more rigorous definition of severe grade IV and V renal injuries.The last article analyses the diagnostic angiography and angioembolization in the acute management of renal trauma using a nationaldata set in the USA. The EBT-TACS Journal Club elaborated conclusions and recommendations for the management of high-grade renal trauma.

Lack of association between the ICIQ-SF questionnaire and the urodynamic diagnosis in men with post radical prostatectomy incontinence / Falta de associação entre o questionário ICIQ-SF e o diagnóstico nos homens portadores de incontinência urinária pós-prostatectomia radical

PURPOSE: To analyze the correlation between the "International Consultation on Incontinence Questionnaire-Short Form" (ICIQ-UISF) survey and the urodynamic findings in men with urinary incontinence (UI) following radical prostatectomy (RP). METHODS: 88 men who presented post-RP UI for a minimum of 1 year were enrolled prospectively. All answered the ICIQ-UISF survey and underwent urodynamic testing. Patients were divided in 3 Groups according to their urodynamic diagnosis: Group 1, patients with sphincteric incontinence (SI) alone; Group 2, patients with mixed UI (SI + Bladder Dysfunction (BD)); and Group 3, patients with BD alone. Data were analyzed using SPSS v16.0 software. RESULTS: There were 51 men in Group 1 (57.9%); 30 in Group 2 (34%); and 7 (7.9%) in Group 3. BD was found in 37/88 patients (42%), but it was the main cause of UI in only 14 patients (15.9%). There was no statistically significant difference among the mean ICIQ-UISFs values from groups 1, 2, or 3 (p>0.05). The symptoms of stress incontinence correlated with the urodynamic finding of SI (r = 0.59), and complaints of urinary urgency correlated with the presence of detrusor overactivity (DO) (r = 0.37), but these complaints did not predict the main cause of UI. CONCLUSION: The etiology of UI following RP cannot be predicted by the ICIQ-UISF survey. Symptoms of stress and urge incontinence predict the findings of SI and DO on urodynamic tests, but they cannot ascertain the main cause of UI. Urodynamic testing remains the gold standard to assess the etiology of post-RP UI.

OBJETIVO: Analisar a relação entre as queixas clínicas mensuradas pelo "International Consultation on Incontinence Questionnaire-Short Form" (ICIQ-UISF) e os achados urodinâmicos em homens com incontinência urinária (IU) após a prostatectomia radical (PR). MÉTODOS: 88 homens que apresentavam IU por um período mínimo de 1 ano após a PR foram incluídos prospectivamente. Todos responderam o questinário "ICIQ-UISF" e foram submetidos a avaliação urodinâmica. Os pacientes foram categorizados em 3 grupos de acordo com o diagnóstico urodinâmico: Grupo 1, pacientes com incontinência esfincteriana isolada (IE); Grupo 2, pacientes com IU mista (IE + disfunção vesical (DV)); e Grupo 3, pacientes com DV isolada. Os dados foram analisados utilizando o software SPSS v16.0. RESULTADOS: Dos 88 pacientes avaliados, após a avaliação urodinâmica, 51 homens (57,9%) apresentaram IE isolada (Grupo 1); 30 homens (34%) apresentaram IE associada a DV (Grupo 2) e 7 homens (7,9%) tinham somente DV (Grupo 3). A DV foi encontrada em 37/88 pacientes (42%), mas foi a principal causa de IU em apenas 14 pacientes (15,9%). Não houve diferença estatisticamente significativa entre os valores das médias do "ICIQ-UISFs" entre os grupos 1, 2 ou 3 (p> 0,05). Os sintomas de incontinência de esforço se correlacionaram com o diagnóstico urodinâmico de IE (r = 0,59), e as queixas de urgência miccional se correlacionaram com a presença de hiperactividade do detrusor na avaliação urodinâmica (r = 0,37), entretanto apesar da correlação encontrada, os sintomas não foram capazes de identificar a principal causa da UI . CONCLUSÃO: A etiologia da UI após a PR não pode ser previsto pelo escore de sintomas obtidos através do "ICIQ-UISF". Os sintomas de perda urinária as manobras de estresse e de urgência miccional estão relacionados a presença de IE e hiperatividade detrusora na avaliação urodinâmica, entretanto estes sintomas não conseguem identificar com segurança qual é o principal fator da IU após a PR.O teste urodinâmico continua sendo o padrão ouro para avaliar a etiologia da IU após a PR.

Cutaneous ureterostomy with definitive ureteral stent as urinary diversion option in unfit patients after radical cystectomy / Ureterostomia cutânea como opção de derivação urinária em pacientes em condições clínicas após cistectomia radical

PURPOSE: Simple diversions are underutilized, mostly for unfit, bedridden, and very self-limited patients requiring palliative surgical management due to life-threatening conditions. Experience with cutaneous ureterostomy (CU) as palliative urinary diversion option for unfit bladder cancer patients is reported. METHODS: We retrospectively reviewed clinical and operative parameters of 41 patients who underwent CU following RC in three specialized Cancer Centers from July/2005 to July/2010. Muscle-invasive disease (clinical Stage T2/worse), multifocal high-grade tumor, and carcinoma in situ refractory to intravesical immunotherapy were the main indications for RC. Double-J ureteral stents were used in all patients and replaced every 6 months indefinitly. Peri-operative morbidity and mortality were evaluated. RESULTS: Median age was 69 years (interquartile range - IQR 62, 76); 30 (73%) patients were men. Surgery in urgency setting was performed in 25 (61%) of patients, most due to severe bleeding associated with hemodynamic instability; 14 patients (34%) showed an American Society of Anesthesiologists score 4. Median operative time was 180 minutes (IQR 120, 180). Peri-operative complications occurred in 30 (73%) patients, most Clavien grade I and II (66.6 %). There was no per-operative death. Re-intervention was necessary in 7 (17%) patients. Overall survival was 24% after 9.4 months follow-up. CONCLUSIONS: CU with definitive ureteral stenting represents a simplified alternative for urinary diversion after palliative cystectomy in unfit patients. It can be performed quickly, with few early and late postoperative complications allowing RC in a group of patients otherwise limited to suboptimal alternatives. Future studies regarding the quality of life are warranted.

OBJETIVO: Relatar a experiência do emprego da ureterostomia cutânea (UC) como forma de derivação urinária definitiva em pacientes portadores de neoplasia vesical avançada, em más condições clínicas e que necessitam de tratamento paliativo. MÉTODOS: Foram analisados retrospectivamente os parâmetros clínicos e operatórios de 41 pacientes submetidos a cistectomia radical e UC em três centros oncológicos especializados. A UC foi a derivação urinária escolhida quando os pacientes não apresentavam condições clínicas de serem submetidos a outro tipo de derivação . Foram avaliados a morbidade peri-operatória e a sobrevida global. RESULTADOS: A idade média dos pacientes foi de 69 anos (intervalo interquartil - IQR 62, 76); 30 (73%) pacientes eram do sexo masculino. Vinte e cinco pacientes (61%) foram submetidos a cirurgia de urgência sendo a maioria devido a hemorragia grave associada a instabilidade hemodinâmica. O tempo cirúrgico médio foi de 180 minutos (IQR 120, 180). As complicações peri-operatórias ocorreram em 30 (73%) pacientes sendo a maioria classificadas como "Clavien" graus I e II (66,6%). Não houve óbito per-operatório. A reabordagem cirúrgica foi necessária em 7 (17%) dos pacientes e a sobrevida global foi de 24% após 9,4 meses de seguimento. CONCLUSÕES: A UC com implante de "stent" ureteral é uma alternativa simples de derivação urinária, após cistectomia paliativa, em pacientes sem condições clínicas de serem submetidos a procedimentos cirúrgicos mais complexos. A UC é um procedimento rápido e apresenta taxas de complicações aceitáveis. Essa alternativa cirúrgica permite melhorar a qualidade de vida dos pacientes portadores de tumores vesicais localmente avançados.

Antegrade pressure measurement of urinary tract in children with persistent hydronephrosis

INTRODUCTION: Dilation of urinary tract occurs without the presence of obstruction. Diagnostic methods that depend on renal function may elicit mistaken diagnosis. Whitaker (1973) proposed the evaluation of urinary tract pressure submitted to constant flow. Other investigators proposed perfusion of renal pelvis under controlled pressure, making the method more physiological and reproducible. The objective of the present study was to evaluate the results of the anterograde pressure measurement (APM) of the urinary tract of children with persistent hydronephrosis after surgery suspected to present persistent obstruction. MATERIALS AND METHODS: Along 12 years, 26 renal units with persistent hydronephrosis after surgery (12 PUJ and 14 VUJ) were submitted to evaluation of the renal tract pressure in order to decide the form of treatment. Previous radionuclide scans with DTPA, intravenous pyelographies and ultrasounds were considered undetermined in relation to obstruction in 10 occasions and obstructive in 16. APM was performed under radioscopy through renal pelvis puncture or previous stoma. Saline with methylene blue + iodine contrast was infused under constant pressure of 40 cm H2O to fill the urinary system. The ureteral opening pressure was measured following the opening of the system and stabilization of the water column. RESULTS: Among the 10 cases with undetermined previous diagnosis, APM was considered non-obstructive in two and those were treated clinically and eight were considered obstructive and were submitted to surgery. Among the 16 cases previously classified as obstructive, nine confirmed obstruction and were submitted to surgery. Seven cases were considered non-obstructive, and were treated clinically, with stable DMSA and hydronephrosis. CONCLUSIONS: APM avoided unnecessary surgery in one third of the cases and was important to treatment decision in 100%. We believe that this simple test is an excellent diagnostic tool when selectively applied mainly in the presence of functional deficit.