Giant hydronephrosis is a rare condition described for the first time by Sterling in 1939. It is defined as a collection of urine beyond 1.5 liter in the kidney excretory cavities. We hereby report the frequency, the etiologises and the therapeutic attitude about 4 cases in the urology department of the national university healthcare, CNHU HKM of Cotonou.
1) First case: Madam H.N., aged 26 years, with no medical history, is admitted as a result of painful left flank mass. The history reveals a beginning dating back to eight years of abdominal and lower left back pain and hyperthermia of 38.5˚C - 39˚C, suggesting acute pyelonephritis. A treatment using Ceftriaxone 2 g/d, pyroxicam 1capsule/d, ketoprofen 1 tablet/d was administered for three weeks on the basis of cytobacteriological urine exam, which was tested positive to E. coli. The fever and lower left back pain disappeared with the development of the condition. The physical examination revealed a large left flank mass, mobile by bimanual palpation, renal ballottement and divided at the front by left colic tone. The renal function was evaluated only by clotting test and hematologic profile because of lack of radionucleide scan (DTPA, MAG3). The percentage of remaining kidney function should be evaluated to assess separated kidney function. The patient was only able to assess renal ultrasound which showed in the left kidney an echogenic mass with large dilatation of the pelvicalyceal system and thinning of the corticomedullary boundary to 8 mm. The IVU after iodine allergy test reveals grade IV giant bilobed hydronephrosis. The surgery consisted in uncrossing the left lower pole pedicle with the ipsilateral ureter. The furosemide test enabled to identify the stenosis at the ureteropelvic junction. We were able to draw up 1500 cc of clear urine through pyelotomy. Following modeling resection of the pelvis, pyeloplasty was carried out according to KÜSS-HEYNES-ANDERSON technique without pyelostomy intubation. Drainage of the renal cortex was conducted with a silicone drain for 4 days. There were no complaints from the patient after consultation two and four months later. The ultrasound made six months after patient discharge, reveals a normal kidney and cortico-medullary index of 1 centimeter. This return of the kidney to normal status can be surprising because it is not the general rule. We explain it by the ureter liberation from the vascular bridge and its calibration by surgery.
2) Second case: Madam G.C., aged 55 years, overweight, is admitted for left flank febrile seizures extending to the root of the thighs, external genitals, without antalgic posture, along with vomiting and hyperthermia of 38.5˚C. The condition evolved intermittently for the past five years. Herpast history comprised type 2 diabetes and hypertension well taken care for.
The physical examination reveals left flank ovoid mass, bimanual palpation and renal ballottement. We conducted urine sampling for cytobacteriological exam, urine culture and sensitivity test and then a probabilistic antibiotic therapy was carried out. The renal ultrasound imaging reveals a giant hydronephrosis, fully laminated cortico-medullary at 3 mm without ureteral visualization. The Intravenous Urography (IVU) on the abdominal x-ray showed five calyx and pyelic nephrolithiasis. The x-ray after injection shows nonfunctioning kidney from the 10th rib to the left iliac fossa. The blood test reveals no particularity (hemoglobin level was 13.5 g/dL, prothrombinemia 100%, creatinine 11 mg/L, blood glucose 1.70 g/L, and C-reactive protein negative). A nephrectomy through left lumbotomy revealed a huge distended left kidney from which 500 cc of urine was drained to have a good view of the pedicle for easy removal. The ureterectomy was carried out deep down to the pelvis. The ureteropelvic junction was impermeable. The surgical specimen contained 1200 cc with 2 big nephrolithiasis of 50 mm and 30 mm diameter. The other three were 5 mm in diameter. The renal cortex was drained by externalized silicone drain sloping on the left flank. Post-operative course was characterized by parietal suppuration recovered through wicking.
3) Third case: Miss T.A., aged 19, admitted for a large abdominal mass predominant in the left flank, pain and hyperthermia of 39˚C. The history revealed a beginning of such condition dating back to childhood, characterized by paroxysmal pain, vomiting and sometimes uncontrolled hyperthermia. Her medical history indicated a white laparotomy suspected to be left ovary cyst. The clinical examination revealed altered general condition, a temperature of 39˚C and laparotomy wound. The left lumbar fossa was filled, bimanual palpation and renal ballottement. There was an intractable adductus-flexum and a left femoral reducible tumefaction. The vaginal examination showed painful rounded Douglas pouch. The ultrasound revealed a giant left hydronephrosis. The IVU confirms grade IV ectopic kidney hydronephrosis. The treatment of different complications enabled to carry out a left nephrectomy and Hartmann procedure. Post-operative course was simple.
4) Fourth case: S.T. aged 14 years underwent medical consultation for abdominal pains and increasing volume of the abdomen evolving for 2 years associated with disorders of the transit causing nausea, vomiting and constipation. A year ago, a terminal hematuria, spontaneously resolved was documented.
The physical examination enabled to locate an important abdominal curvature extending from the left hypochondrium to the left iliac fossa, with stony dull percussion, painless and with no collateral venous circulation.
The blood count showed isolated normocytic normochromic anemia of 8 g/dl; the urine was sterile. The abdominal ultrasound showed a mass fluid structure extending from the left hypochondrium to the pelvis and exceeding the median line. The abdomino-pelvic CT scan showed a voluminous left compartmentalized hydronephrosis occupying the whole left abdomino-pelvic cavity causing reflux of the digestive structures to the right. That kidney provoked mass effect on adjacent digestive loops and ureteropelvic junction syndrome was strongly suspected. We observed a mild renal compensatory hypertrophy. A nephrectomy was carried out through midline laparotomy. The content was 4.5 liters of urine. Post-operative course was simple.
Giant hydronephrosis is a rare urological condition. Despite some controversies, hydronephrosisis is termed giant when its content reaches or exceeds 1.5 liters. The volume described is variable. It ranged from 1.5 L to 4.5 L in the cases we report. In 1749, Glass et al.  reported the first case. It was a giant hydronephrosis of 15 liters discovered post-mortem. Tombari et al.  reported a historic case of 52 liters and Tulp et al.  another case of 32 liters.
Giant hydronephroses are the result of poor knowledge of the ureteropelvic junction anomaly either prenatally (case 3) or due to delay in consultation (case 4). This pathology affects both genders and is more recurrent among men with a sex ratio 3/1. Viville et al.  reported 2/1 and Mouneer et al.  3/1. Our 4 cases relate to women. The mean age was 28.5 years (ex: 14 years and 55 years) vs 21 years (ex: 0 and 56 years), 15 years (1 I - 79 years) for Viville et al.  , and 22 years (30 I - 75 years) for Noda et al.  . The left flank was dominant among women 4/4 cases vs against a 3/2 in a previous study  , whereas it is right flank among men (ratio 2/1). These results corroborate the ratio of 34 right flanks and 14 left flanks recorded by Viville et al.  whereas Bernheim et al.  in Tel Aviv found no dominant flank.
The most frequent reason for consultation was variable flank pain, ranging from dreadful   to paroxysmal. In other cases, the painful syndrome was accompanied by hyperthermia which first suggested acute pyelonephritis (cases 3 and 4)  . The triggering factors were often correlated with a long trip in a sitting position, excessive intake of beverages and stasis infection   suggesting a lithiasis of the ureteropelvic junction. The clinical examination was poor and often revealed the large kidney through bimanual palpation and renal ballottement. The colonic tone obstructing the renal mass was irregular.
Renal function may be maintained, reduced, or even deteriorated  . The obliteration of the parenchyma is often done slowly and discovered at a late age; it could also evolve rapidly without any symptoms  . At a more advanced stage, the damaged kidney forms a pouch compartmentalized by walls with dilated calyces containing non concentrated urine. The renal ultrasound reveals severe pyelectasis, measures the fluid volume sequestered, calculates the cortico-medullary index, indicates the status of the pyeloureteral junction and explores the calcifications in the renal projection region. In the absence of contra-indication, the IVU shows delayed secretion and opacification; values the importance of dilation which could extend from the 10th rib to the ipsilateral iliac fossa (cases 2, 3, and 4) late time  . The CT urography suggests pyelectasis with no downstream ureteral dilation. The gold standard of the renal function screening is radionucleide scan which assess separated kidney function whether by DTPA or by MAG3. Evaluation of the percentage of remaining kidney function is useful to give accurate surgical decision. But we have none of these tools in our units. The assessment of complications revealed presence of competitive morbidity factors in the case of the second patient namely: old age, high blood pressure and diabetes. In some cases, this co-morbidity can associate variable kidney failure, physical status score and Karnofsky performance scale index meeting the Anglo-Saxon “coexistent disease index”. The disease assessment revealed a long period of development and late consultation.
Based on the ultrasound, the cortico medullary index was compatible with good renal function in one case, whereas it wasn’t the case in the other three. In the first observation, the intravenous urography showed an Hourglass sign of the kidney and pelvic cavity. This aspect is suggestive of either a lower pole pedicle or fibrous band  . The Doppler echocardiography confirmed the association of a lower pole pedicle with the pyeloureteral junction syndrome. In the second observation, in addition to diabetes known for its metabolic lithogeticrole and infectious risk, the junction syndrome was complicated by lithiasis caused by stasis. Stasis is favorable for infection and lithiasis  . This pathophysiology explains the incidence of pyelonephritis observed in this case. Without prejudice to the etiology of urolithiasis or nephrolithiasis, it is obvious that these two etiologies are intertwined. In the third observation, the urography suggests left pelvic ectopic kidney on the basis of pyeloureteral junction syndrome. Once, the surgical indication was the lower pole pedicle uncrossing with the ureter associated with a pyeloplasty. Pre-operative drainage can be done either by nephrotomy or into bated pyelotomy. Such measure was not necessary in this indication. Urography remains a preferred choice in so far as this pathology is concerned, because it helps not only to reveal a dilated kidney exceeding the median line, but also to consider the urine volume and assess the impact of renal functionat the injection phase where there is no access to radionucleide scan. Sometimes, as etiology, it reveals the vascular crossing in arterial phase. Urography also detects the associated kidney malformations, complications (nephrolithiasis, urinoma, infection, parenchymal damage) and contributes to pre-operative assessment  .
Therapeutically, nephrectomy is a common practice, especially when the contralateral kidney is normal by the evaluation of the percentage of remaining kidney function  . In this report, three nephrectomies were carried out. However, according to Oka et al.  , when the kidney maintains a parenchymal thickness above 1 cm and a glomerular filtration exceeds 20 ml/min, anetiological and conservative treatment may be carried out especially if the hydronephrosis occurs bilaterally, or on anatomically solitary kidney or when the contralateral kidney alone cannot sustains a normal kidney function  .
Minki et al.  suggest a conservative surgery through pyeloplasty or nephroplication. The associated antibiotic therapy prevents the infectious risk and protects the indication of a percutaneous nephrostomy, pending discussion of a possible nephrectomy or a conservative surgery dependingon the renal function recovery. Out of four observations, three nephrectomies were required. In all four cases, the drainage of the renal cortex was systematic and successfully carried out with alaterally perforated silicone drain.
Post-operative course was simple and patients were discharged without any incident. There were no complaints reported by surgical patients during consultation. The first patient ultrasound carried out in the 6th month shows normal renal recovery. The renal function of these four patients is normal and they enjoy good health.
Giant hydronephrosis is rare and the most frequent etiology is the pyeloureteral junction syndrome. Enclosed lithiasis of the junction, ureteral tumor, lower pole pedicle and fibrous band are also documented. Sonography prevailed over IVU in the diagnosis. When the contra kidney function is normal, nephrectomy is the gold-standard.
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