Acute Urinary Tract Obstruction Research Articles

Does the kidney actually swell during an acute urinary tract obstruction?

The appearance of renal swelling during an acute obstruction of the urinary tract could be caused by hydronephrosis or an increase of the parenchymal volume. To the best of our knowledge no studies have been performed regarding renal parenchymal volume change during an acute urinary tract obstruction. To investigate the change in renal parenchymal volume during an acute urinary tract obstruction and to correlate any such volume change to the degree of secondary signs of obstruction. In total, 20 patients with obstructive ureterolithiasis were retrospectively and randomly included. Two observers measured the parenchymal volume of the obstructed and the contralateral kidney in CT examinations before, during, and after obstruction. Hydronephrosis, hydroureter, perirenal stranding, and thickening of the renal fascia were graded and correlated to volume change. A decreased volume was noted after obstruction in the obstructed kidneys (-24%) (P < 0.0001) and in the contralateral kidneys (-5%) (P = 0.0110) with a positive correlation of change in volume (P = 0.011). The volume of the obstructed kidneys was larger than the contralateral kidneys during obstruction (P < 0.0001) but not after obstruction (P = 0.559). No significant difference in volume was found before compared to after obstruction. Secondary signs of obstruction did not correlate to volume change. The parenchymal volume increases in the obstructed kidneys as well as in the contralateral kidneys during obstruction. The increase in volume was larger in the obstructed kidneys compared to the contralateral kidneys. After obstruction the kidneys regained their original volume. Secondary signs did not correlate to volume change.

Unilateral "white pyramid" sign in acute urinary tract obstruction.

Unilateral "white pyramid" sign in acute urinary tract obstruction.

Symptom of renal pelvic “pseudodissection” with computed tomography as a sign of pyelosinus reflux and urine extravasation

The purpose of the study . To find typical computed tomographic signs of pyelosinus reflux with a small amount of extravasation of urine. Material and methods . Eight observations were analyzed in which there was extravasation of urine into the renal sinus detected by CT. Results . In six cases, the changes were on the right, in two – on the left side. The cause of acute urinary tract obstruction in four cases were ureteral stones, in two cases there was compression of the ureter from the outside by a pelvic tumor. In two cases, a day after the relief of renal obstruction, the contrasted urine outside the pelvic was not determined. Additional findings were: flection of the ureter in two cases, renal sinus cysts – in four observations. In four observations an unusual “pseudodissection” of the renal pelvis in the excretory phase was revealed, which consisted in the presence of a thin non-contrasting layer "dividing" the contrasted contents of the pelvis into two parts. Conclusions . 1. Identification of the pattern of “pseudodissection” of the pelvis is practically a pathognomonic computed tomographic symptom of extravasation of urine as a result of pyelosinus reflux and rupture of renal calices. 2. Resolution of ureteral obstruction can lead to complete normalization of the computed tomographic picture during the day. 3. Inflection of the ureter, cysts of the sinus of the kidney, may be provoking factors of extravasation of urine in acute ureteral obstruction, but this requires further study.

Complete inguinal bladder hernia causing acute right upper urinary tract obstruction

Case Summary: An 86-year-old male nursing home resident presented with increasing confusion and was initially treated for catheter-associated urinary tract infection. Computed tomography (CT) scan demonstrated complete inguinal bladder hernia with compression of the right vesico-ureteric junction leading to acute obstructive renal failure. Percutaneous nephrostomy was attempted but was not possible due to patient non-compliance. Patient improved with conservative management. Discussion: Bladder involvement in inguinal hernia is rare with most cases being identified at the time of hernia repair and there is a 17% risk of intra-operative bladder injury. Key risk factors include increasing age, male gender, lower urinary tract symptoms and previous hernia repair. Percutaneous nephrostomy followed by inguinal hernia repair is the treatment of choice for most patients. This case highlights that inguinal bladder hernia can lead to acute upper urinary tract obstruction even when the bladder is catheterised. Level of evidence: IV

Prospective determination of the incidence and severity of hyponatraemia in older hospitalised patients with acute urinary tract obstruction.

acute urinary tract obstruction (aUTO) is a common finding in older hospitalised patients. Anecdotal reports described hyponatraemia in patients with aUTO, which subsides rapidly with relief of the obstruction.The aim of this study was to determine the incidence, severity and subsequent correction of hyponatraemia in patients with aUTO. this is a prospective, single-centre, observational study including inpatients in the internal medicine and geriatric wards. A total of 204 patients were investigated, 104 with aUTO and 100 controls. The prevalence, severity and associations of hyponatraemia between aUTO and control patients were compared. the incidence of hyponatraemia was similar in aUTO and control groups 28% versus 22%, respectively (P = 0.42). However, the incidence of severe hyponatraemia was significantly higher in the study group 7% versus 1% (P = 0.04). Mean sodium level was lower in hyponatremic patients with aUTO 127.7 ± 5.9mEq/l versus 130.8 ± 3mEq/l (P = 0.013). Serum sodium remained largely unchanged in the control group (∆Na 1.5 ± 2.3mEq/l) but increased significantly within 48hours following catheter insertion in patients with urinary retention (∆Na 5.3 ± 4.2mEq/l overall in the aUTO group and 9.6 ± 3mEq/l in those with urinary retention and severe hyponatraemia (P = 0.002)).

Restricted diffusion MRI as a functional biomarker for the assessment of acute calcular upper urinary tract obstruction: initial experience

BackgroundAcute renal obstruction due to stone is a prevalent scenario. The diffusion-weighted magnetic resonance imaging (DWI) of the kidneys provides a noninvasive information on renal function. Our objective is to prospectively assess the potential role of DWI to predict the signal changes of a kidney with acute calcular obstruction.ResultsChi-square and Fissure exact tests were used to assess the association of diffusion signal changes among patients and control groups. Cohen's Kappa test was run to determine the degree of agreement between the two radiologists. An independent sample t-test was performed to assess the significant difference among ADC values between the two groups. Restricted signals of the obstructed kidneys showed a statistically significant difference when compared with contralateral unobstructed kidney and control group with p value (0.001) and (0.01), respectively. Furthermore, there is a moderate agreement between the two radiologists K = 0.7, p = 0. 001. There is no statistically significant difference in ADC values when comparing the obstructed kidney and the contralateral unobstructed kidney of the patient group or with the control group p value (0.06) and (0.05), respectively.ConclusionRestricted signals of the obstructed kidney by DWI may be a helpful tool in diagnosing acute unilateral renal obstruction and can affect its management; however, it needs further validation by more studies.

297 Risks of Delaying De-Obstruction of an Acutely Infected Obstructed Urinary Tract

Abstract Introduction We investigated patients with acute urinary tract obstruction in a DGH to ascertain which factors predispose to CKD and mortality. Method Over five months there were 37 nephrostomy/stent cases, 18 female, 3 mortalities. Median age was 55.5 (18-93). Retrospective data was used in a multiple regression analysis. Input variables included the intervention indication, admission Creatinine, Charlson Co-morbidity Index, and intervention delay. Output variables were length of hospital stay, renal function and 90-day mortality. Results Positive urine cultures (p = 0.035) and co-morbidity (p = 0.018) were associated with CKD. Nephrostomy patients (p = 0.031) were associated with AKI post-procedure. Delay in disobstruction (p &amp;lt; 0.01) and delay-length (p = 0.026) were significantly associated with longer hospital stays. AKI severity on admission (p = 0.047) and intervention delay (p = 0.045) increased risk of 90-day mortality, with positive blood cultures (p = 0.071) trending towards significance. Malignant obstruction neared a significant association with CKD (p = 0.08) and 90-day mortality (p = 0.075). Conclusions The severity of presentation and delay in intervention all contribute to poorer outcomes and a longer admission. Co-morbid patients with malignant obstruction had a higher risk of 90-day mortality. Therefore, in those with poor baseline, are we intervening inappropriately?

Percutaneous nephrostomy versus retrograde ureteral stent for acute upper urinary tract obstruction with urosepsis

PurposeWe aimed to compare the efficacy of percutaneous nephrostomy (PCN) versus retrograde ureteric stent (RUS) for acute upper urinary tract obstruction with urosepsis. Materials and methodsWe performed a random study, comparing PCN to RUS, for the treatment of patients requiring emergency drainage due to acute upper urinary tract obstruction with urosepsis between January 2019 to March 2020. Data collected included patient characteristics, stone material, microbiological characteristics, and laboratory data. Statistical analysis was performed by the student's t-test or Mann-Whitney U test or chi-squared test and Fisher exact test. ResultsAt first, a total of 75 patients were eligibly assessed for enrollment. Among them, 3 cases were excluded for declining to participate and 7 cases were failed treated with RUS. At last, 35 PCN (53.85%) and 30 RUS (46.15%) patients were analyzed. There were 24 (36.92%) men and 41 (63.08%) women. The median age was 65 years. Emergency decompression was achieved by PCN in 35 (53.85%) patients and by RUS in 30 (46.15%). Urine culture was positive in 32 (49.23%) patients, of which 17 (53.13%) had E. coli. Postoperative C-reactive protein value and normal temperature recovery time in the PCN group were significantly lower than in the RUS group(P < .05). ConclusionPCN had a better outcome than RUS in emergency drainage with urosepsis, especially for patients with severe inflammation and fever.

Spontaneous bilateral renal pelvis rupture during CT in the absence of urinary tract obstruction: case report

BackgroundAtraumatic renal pelvis rupture without pre-existing renal or ureteric pathology is an uncommon event. It is reported in the setting of acute urinary tract obstruction, most often secondary to ureteric calculi. Typical symptoms include acute flank pain and nausea, mimicking pyelonephritis or other causes of acute abdomen. Spontaneous rupture occurring bilaterally without identifiable urinary tract obstruction is exceedingly rare, and has yet to be reported in current English literature. Possible contributing pathophysiological mechanisms can be postulated from reported cases of rupture with observed obstruction.Case presentationA 58-year-old woman undergoing multiphasic computed tomography (CT) for evaluation of asymptomatic microscopic haematuria developed on-table bilateral renal pelvis rupture seen only after contrast administration, on the delayed phase. There was no significant past medical history of note. The patient remained asymptomatic throughout and after the study, and was managed conservatively. Follow-up radiographical imaging over a month showed resolution of urinoma and no further contrast extravasation. No complications or recurrence was subsequently noted.ConclusionsSpontaneous rupture of the renal pelvis can be a rare complication of intravenous contrast administration even in cases without identifiable urinary tract obstruction, and it can occur bilaterally. Cases can uncommonly be asymptomatic but typical symptoms should prompt evaluation of the kidneys, particularly when they are not included in the initial study or no delayed phase is protocolled. Interval imaging for resolution of urinoma and contrast extravasation is clinically relevant to monitor for and avoid infective sequelae.

Endothelins contribute to early renal insufficiency engendered by acute urinary tract obstruction in neonatal pigs

Urinary tract obstruction reduces kidney functions, which, if left uncorrected, may lead to irreversible renal loss, especially in infants. Despite the removal of obstruction, a decline in steady‐state renal blood flow (RBF) persists, vascular mechanisms of which are poorly understood. Urinary tract obstruction‐induced increase in the levels of vasoactive endothelin (ET)‐1 has been reported in humans and rodents. However, whether obstructive renal vasculopathy is associated with increased renal production of all ET isoforms (ET1‐3) remains unresolved. Also, the mechanisms that underlie ET‐induced renal vasoregulation in neonates are unclear. Here, we show that ET receptor (ETR)‐operated calcium entry via TRPC3 channels increases renal vascular resistance and reduces RBF in neonatal pigs. Acute unilateral urinary tract obstruction (UUO) in neonatal pigs increased peptidase endothelin converting enzyme 1 (ECE1)‐dependent renal production of ET1‐3 and diacylglycerol (DAG). Despite the removal of obstruction, acute UUO reduced kidney perfusion and caused an increase in renal vascular resistance (RVR) and the urinary levels of NGAL, the early predictive biomarker of acute kidney injury. The protein expression levels of ETRs (ETA and ETB) and TRPC3 channels in renal microvessels were unaltered in neonatal pigs subjected to acute UUO. However, pharmacological inhibition of ECE1, ETR, and TRPC3 mitigated acute UUO‐induced increase in RVR and urine NGAL in the pigs. These data suggest that increased ECE1 production and proteolytic processing of all big ETs to their vasoactive isoforms contribute to early neonatal renal insufficiency engendered by UUO. ET‐derived DAG activates renal vascular smooth muscle cell TRPC3 channels, leading to extracellular calcium entry, vasoconstriction, increased RVR and sustained hypoperfusionSupport or Funding InformationNIH/NIDDK: R01DK101668 and R56DK120595

Minimally invasive management of acute ureteral obstruction and severe infection caused by upper urinary tract calculi.

PURPOSETo evaluate therapeutic efficacy of two minimally invasive surgical methods in managing acute ureteral obstruction and severe infection caused by upper urinary tract calculi (UUTC).PATIENTS AND METHODSData of 47 patients diagnosed with acute upper urinary tract obstruction and severe infection caused by ureteral calculus using X-ray CT between September 2014 and January 2019 were retrospectively analyzed. All patients were treated with immediate renal drainage and, after infection and ureteral obstruction were relieved, UUTC removal. Renal drainage was performed by ultrasound-guided percutaneous nephrostomy and retrograde ureteral catheterization was performed using cystoscopy. Kidney and ureteral stones were removed; renal function and the urinary tract were examined by X-ray during follow-up.RESULTSPercutaneous nephrostomy was performed in 29 patients in a critical condition including intolerance to surgery, high-grade hydronephrosis, or failure of retrograde ureteric stent placement. In other 18 patients diagnosed with small stones (≤10 mm) and low-grade hydronephrosis, indwelling double-J ureteral stents were temporally installed by a cystoscope. Acute infection and ureteral obstruction were relieved; white blood cell counts returned to normal values within 3 to 7 days after drainage in all patients. In the second-stage treatment, percutaneous nephrolithotomy (PCNL), ureteroscopic lithotripsy, extracorporeal shock wave lithotripsy and nephrectomy were performed in 24, 10, 8 and 5 patients, respectively. No patients developed severe complication after stone removal surgery. All patients were followed up for 3 months to 4.5 years. Renal function was significantly recovered; 17/29 (59%) patients with elevated serum creatinine returned to normal and serum creatinine in 12/29 (41%) patients improved significantly after drainage, with a pre-operation level of 285±169μM vs 203±91μM post-operation (P = 0.014). Five patients were lost during follow-up.CONCLUSIONThis study demonstrated an optimal approach for relieving upper urinary tract obstruction and acute infection in which percutaneous nephrostomy drainage is preferred for patients with severe pyonephrosis, large stones (>10 mm) with high-grade hydronephrosis, steinstrasse, or failure in retrograde ureteric stent placement, while retrograde ureteral catheterization using cystoscopy is suitable for patients diagnosed with small stones (≤10 mm) and low-grade hydronephrosis.

ARFI shear-wave elastography with simulation of acute urinary tract obstruction in an ex vivo porcine kidney model.

A total of 20 heparinized pig kidneys were investigated at 10 intrapelvic hydrostatic pressure steps (0-90 mmHg). SWE (ARFI; Virtual TouchTM IQ, Siemens) measurements were taken at three different measuring regions and in two measuring sequences using a linear ultrasonography probe (9L4, Siemens). Median values of 10 shear-wave speed (SWS) measurements were calculated for each pressure step. Logarithmic transformed median SWS values were analyzed in a linear mixed model. SWS increased significantly with increasing intrapelvic pressure. Median SWS for all kidneys in both measuring sequences and all measuring regions was 1.47 m/s (interquartile range [IQR], 0.38 m/s) at 0 mmHg, 1.94 m/s (IQR, 0.42 m/s) at 30 mmHg, 2.07 m/s (IQR, 0.43 m/s) at 60 mmHg, 2.24 m/s (IQR, 0.49 m/s) at 90 mmHg. The correlation between pelvic pressure increase and median SWS values for the central parenchyma was significantly higher compared with the peripheral parenchyma. Acutely increased renal pelvic pressure correlates with increasing SWS values in ARFI elastography in an ex vivo porcine kidney model.

Acute Urinary Tract Obstruction

Abstract The kidneys are paired organs with the primary function of helping to remove toxins from the body and regulate water balance. They are vital to survival. After urine is produced in the kidneys, it must pass into the bladder, where it can be stored before being eliminated from the body through the urethra. Urinary tract obstruction is a common problem encountered by urologists, primary care physicians, and emergency medicine physicians. Urine can become obstructed at any point in this pathway. There are three groups of urinary tract obstructions: 1) obstruction of the urinary tract lumen; 2) obstruction of the urinary tract wall; and 3) extrinsic obstruction, which can press on the urinary tract lumen. An obstruction can be present from birth or develop later in life. The most common causes of obstruction include stones, strictures, tumours, and bladder dysfunction. These obstructions may result in the hydronephrosis of one or both kidneys, which, if left untreated, may lead to the deterioration of renal function. The goal of an initial treatment of urinary tract obstruction is to remove the obstruction. Later, we treat the cause that led to the obstruction. The bottom line is that all efforts should be made to preserve kidney function to avoid the need for dialysis or renal transplantation.

Clinical treatment for acute upper urinary tract obstruction wihout urine complicated with serious infection

Objective To study the clinical treatment for acute upper urinary tract obstruction wihout urine complicated with serious infection.Methods The clinical data of 26 patients with acute upper urinary tract obstruction wihout urine complicated with serious infection were retrospectively analyzed.Results After the comprehensive treatment,25 patients' conditions got stable and improved,their urine was recovered,their serum creatinine and urea nitrogen were decreased,their white blood cells and neutrophil returned to normal,and they discharged after 12 ～ 23 d hopitalization.1 case had multiple organ failure and died.Conclusions Effectively controlling infection,improving the condition,and removing the obstruction in time are effective methods to treat acute upper urinary tract obstruction wihout urine complicated with serious infection. Key words: Upper urinary tract; Acute obstruction; Renal failure; Serious infection

Functional Multiparametric Magnetic Resonance Imaging of the Kidneys Using Blood Oxygen Level Dependent and Diffusion-Weighted Sequences

Little data are available on noninvasive magnetic resonance imaging based assessment of renal function during upper urinary tract obstruction. We determined whether functional multiparametric kidney magnetic resonance imaging could monitor the treatment response in cases of acute unilateral upper urinary tract obstruction. Between January 2008 and January 2010, 18 patients with acute unilateral upper urinary tract obstruction due to calculi were prospectively enrolled to undergo kidney magnetic resonance imaging with conventional, blood oxygen level dependent and diffusion-weighted sequences upon emergency hospital admission and after release of obstruction. We assessed functional imaging parameters of obstructed and contralateral unobstructed kidneys derived from blood oxygen level dependent (apparent spin relaxation rate) and diffusion-weighted (total apparent diffusion coefficient, pure diffusion coefficient and perfusion fraction) sequences during acute upper urinary tract obstruction and after its release. During acute obstruction the apparent spin relaxation rate and perfusion fraction were lower in the cortex (p=0.020 and 0.031) and medulla (p=0.012 and 0.190, respectively) of obstructed kidneys compared to contralateral unobstructed kidneys. After obstruction release the apparent spin relaxation rate and perfusion fraction increased in the cortex (p=0.016 and 0.004) and medulla (p=0.071 and 0.044, respectively) of formerly obstructed kidneys to values similar to those in contralateral kidneys. Total apparent diffusion coefficient and pure diffusion coefficient values did not significantly differ between obstructed and contralateral unobstructed kidneys during or after obstruction. In our patients with acute unilateral upper urinary tract obstruction due to calculi functional kidney magnetic resonance imaging using blood oxygen level dependent and diffusion-weighted sequences enabled us to monitor pathophysiological changes in obstructed kidneys during obstruction and after its release.

Role of MR renography in the evaluation of acute upper urinary tract obstruction

PurposeTo present the role of MR renography in diagnosis of upper urinary tract obstruction (UTO) with evaluation of diagnostic criteria for acute obstruction. Material and methodsThirty consecutive patients with obstructive anuria were included in our study. For identification of the cause of obstruction, all patients were subjected to plain abdominal X-ray (KUB), gray scale ultrasonography, non-contrast CT for the abdomen and pelvis (NCCT). There were five patients with bilateral obstruction and 25 with obstructed solitary functioning kidney, so the study included 35 units. All patients were subjected to radioisotope diuretic renography and magnetic resonance renography (MRR) before relief of obstruction and 3days after drainage. Of the 30 patients included, 20 were men and 10 women. ResultsAmong our patients the mean serum creatinine at time of presentation was 7±4.5mg/dl (range 2.4–12) and GFR ranged from 33 to 48ml/min (mean±SD; 38±4.2). All the renal units have hydronephrosis. The mean pre drainage SI values 133±22 (range 120–180). The mean time to peak (TP) for each unit was 171.6±78s and at isotope renography it was 320±66s. There was good corticomedullary differentiation (CMD) in 31 units and the remaining 4 showed loss of CMD differentiation. The CMD crossing time was 163.6±70.4s. Post kidney drainage the parenchymal SI was increased in 30 units, in 3 units there was drop and no change in 2 (r=0.29). There is relative reduction in the time to peak, it becomes 67±79s after drainage (r=0.76). ConclusionMR renography is a clinically valuable technique that provides diagnostic criteria to diagnose the acute urinary obstruction and allows follow up of renal function.

Evaluation on the effecf of ureterosocopy in treatment of acute upper urinary tract obstructive anuria

Objective To explore the role of ureteroacopy for acute upper urinary tract obstructive anuria.Methods Clinical data of 37 cases with acute upper urinary tract obstructive anuria were analyzed.Results Among 37 cases,34 cases were successfully performed ureteroseopy or ureteroseopic lithotripsy with double-J sent incubation (successful rate was 91.9%).Renal function were recovery in 32 cases.4 Cases returned to 180μmol/L,1 case need hemodialysis periodically.Conclusion Ureteroscopy could rapidly remove the obstruction and protect renal function in management of acute upper urinary tract obstruction anuria,which was contributed to the diagnosis.It was safe,effective and the preferred method. Key words: Ureteroscopy; Ureteral Obstruction

Multislice computed tomography urography in the diagnosis of urinary tract diseases

. Multislice computed tomography (MSCT) has triggered considerable changes in uroradiological imaging. The aim of this study was to establish the place of MSCT urography (MSCTU) in comparison with intravenous urography (IVU) and to determine the sensitivity and specificity of MSCT in the evaluation of urothelial abnormalities. This prospective study included 120 patients with a high clinical suspicion of urinary tract diseases divided into two groups. The group I consisted of 60 patients with macroscopic hematuria, bladder carcinoma and malignant pelvic tumors after radiotherapy or operation. They underwent both IVU and MSCTU. The group II included 60 patients (> or = 40 years old) with retroperitoneal and malignant pelvic tumors, complicated pyelonephritis, microscopic hematuria, acute urinary tract obstruction (without visible calculi on unenhanced scans), and they were submitted to computed tomography with additional scan phase enabling MSCTU. Compared with IVU, MSCTU is more sensitive for the detection of urinary tract diseases (parenchymal changes, renal tumors, urolithiasis, fibrosis) and extraurinary processes. MSCTU is more specific than IVU for renal parenchymal abnormalities, tumors of the excretory system, urolithiasis, bladder tumors, fibrosis and extraurinary diseases. MSCTU is equally sensitive, but more specific for hydronephrosis compared to MSCT. The diagnosis made by the use of MSCTU in patients with macroscopic and microscopic hematuria and with obstruction not caused by stones, perfectly comply with operative findings and histological diagnosis. The obtained results support MSCTU to be the modality of choice in the diagnostic algorithm of patients with macroscopic hematuria and in the evaluation of microscopic hematuria and unexplained obstruction of the urinary tract. The only remaining role for IVU in our institution is imaging of the upper urinary tract in patients with hematuria under the age of 40.

Minimally Invasive Inguinal Approach for Tube Cystostomy

To report a technique for tube cystostomy placement via a minimally invasive inguinal approach and outcome in 9 dogs and 6 cats with urinary tract obstruction or detrusor atony. Case series. Dogs (n=9) and cats (6). Medical records (January 2004-January 2008) of dogs and cats that had tube cystostomy via an inguinal approach were reviewed. Retrieved data included signalment, diagnosis, surgical technique, and complications. Access to the bladder was through a muscle splitting approach in the inguinal region with the cystostomy tube placed through a skin incision made several centimeters proximal to this incision and secured in the bladder by a purse string suture. Cystopexy during closure of the muscle layers ensured secure closure and minimized the likelihood of uroabdomen if tube dislodgment occurred. Cystostomy tubes were placed in 5 cats as an emergency procedure for treatment of acute urinary tract obstruction or urethral rupture, and as an elective procedure in 9 dogs and 1 cat. No complications occurred during cystostomy tube placement. Postprocedural complications were minor (peristomal irritation in 2 dogs with latex catheters, catheter laceration, premature removal) and only occurred when tubes were retained for >4 weeks. Urinary tract infection at catheter removal in 6 dogs resolved with antibiotic administration. An inguinal approach for cystostomy tube placement facilitated rapid catheter placement into the bladder with minimal soft tissue dissection. Cystopexy during abdominal wall closure provided peritoneal protection should premature dislodgement of the cystostomy tube occur. An inguinal approach should be considered for rapid tube cystostomy particularly in metabolically compromised animals.

Comprehensive therapy of the infant urinary calculus induced by melamine

Objective To explore the comprehensive therapy of infants with urinary calculus induced by melamine.Methods Clinical data of 228 infants(aged from 4 months to 3 years,mean age 11 months)with urinary calculus induced by melamine were analyzed. Bilateral renal calculi were found in 144 cases and one-side renal calculus in 54 cases,of which the diameter ranged from 0.5-2.5 cm.Ureteral calculi with moderate to severe hydronephrosis were found in 15 cases,of which the diameter ranged from 0.4-1.1 cm. Bladder calculi with urinary retention were found in 5 cases and urethral calculi with urinary retention in 10 cases,of which the diameter ranged from 0.5-1.3 cm. All the urinary calculi were confirmed by B-uhrasound examination and CT. Group 1 : Of the 15 cases with acute renal failure, 13 underwent shattering and dissolving renal and ureternal calculus by pelvis clysis with alkalinity drug, detaining double J tubes through ureteroscope. After operation, these patients were treated with alkalinity drugs. Two cases were treated by percutaneous nephrostomy guided by B ultrasound and underwent shattering and dissolving renal calculus by intermittent pelvis clysis with alkinity drug. Group 2:15 cases of ureteral calculus with serious nephrohydrops underwent shattering and detaining double J tubes through ureteroscope, then treated with alkalinity drug. Group 3:15 cases of infant bladder and urethral caleus with acute urinary retention were treated by EMS through ureterscope per urethra. Group 4: The rest 183 cases without urinary obstruction received 1-8 week'surine alkalization therapy. Among them, 113 cases received sodium bicarbonate 0.15 g twice per day,23 cases received potassium sodium hydrogen citrate 2.4g/d, and 47 cases received 10% potassium citrate solution 5 ml 3 times per day. Sixty-one cases who were of no effect with alkalinity drug were treated by extracorporeal shock wave lithotripsy (ESWL) and dissolving calculus with sodium bicarbonate. During treatment with alkalinity drug, urine Ph was observed by urine analysis once per day.When it exceeded 7.5, alkalinity drug. Was withdrawn. All the patients were followed up for 1 to 3 months. Statistical analysis was done with the SPSS 13.0 software. ResultsHyperdiuresis emerged 12-24 h after operation in group 1. The duration of hyperdiuresis was 24-72 h with the urine volume of 800-2500 ml/24h. Urine volume revived gradually 48--96h after operation while serum BUN and Cr revived 1-5 d after operation. Four cases with renal and ureteral calculus became almost stone-free in 1-2 weeks and 14 cases became completely stone-free in 2-4 weeks after operation. Patients of group 2 became completely stone-free in 1-2 weeks. Patients of group 3 were cured by one EMS session through ureterscope per urethra and smooth urination was seen immediately after operation. No retained calculus in the bladder and urethra was found by B ultrasound 3 days later. In the sodium bicarbonate group, 4 cases became completely stone-free in 2 weeks, 18 cases in 4 weeks, 15cases in 13 weeks. The stones lessened and faded in 34 cases and had no changes in 42 cases. In the potassiun sodium hydrogen citrate group, 4 cases became completely stone-free in 1 weeks, 7 cases in 2 weeks, 10 cases in 4 weeks, 2 cases in 6 weeks. In the potassium citrate group, 3 cases became completely stone-free in 1 weeks, 5 cases in 2 weeks, 16 cases in 4 weeks, 11 cases in 8 weeks. The stones lessened and faded in 8 cases in 8 weeks and had no changes in 4 cases. The efficacy of the sodium bicarbonate group was significantly different with the efficacy of the citrate group (P=0. 001). No significant difference was found between the potassium sodium hydrogen citrate group and the potassium citrate solution group(P=0. 372). ConclusionsConservative treatment should be employed mainly in the earlier stage for the infant urinary calculus induced by melamine . When the diagnosis of acute renal failure, moderate to severe hydronephrosis and acute lower urinary tract obstruction are established, surgical intervention should be the main method to relieve obstruction, protect renal function and resume normal rnicturition. With the development of the characteristics of the stones later,the oral dissolution therapy with alkalirtity drug could not dissolve the calculi and ESWL should be employed. Key words: Urinary calculi; Infants; Melamine; Combined modality therapy