Microvasculature of hydronephrotic kidneys in KK-A(Y) mice

Large subcapsular hematoma following ureteroscopic laser lithotripsy of renal calculi in a spina bifida patient: lessons we learn

Introduction

Paraplegic patients are at greater risk of developing complications following ureteroscopic lithotripsy because of urine infection associated with neuropathic bladder, difficulties in access due to altered anatomy of urinary bladder and urethra, spinal curvature, spasticity, and contractures. We report the occurrence of large subcapsular hematoma following ureteroscopy and discuss lessons we learn from this case.

Case report

A 48-year-old male patient with spina bifida underwent ureteroscopy with laser lithotripsy and ureteric stenting for left ureteric stone and staghorn calculus with hydronephrosis; laser lithotripsy was repeated after 3 months; both procedures were performed by a senior urologist and did not result in any complications. Ureteroscopic laser lithotripsy was performed 5 months later by a urological trainee; it was difficult to negotiate the scope as vision became poor because of bleeding (as a result of the procedure). Postoperatively, hematuria persisted; temperature was 39°C. Cefuroxime was given intravenously followed by gentamicin for 5 days; hematuria subsided gradually; he was discharged home. Ten days later, this patient developed temperature, the urine culture grew Pseudomonas aeruginosa, and ciprofloxacin was given orally. Computed tomography (CT) of the urinary tract, performed 4 weeks after ureteroscopy, revealed a 9×7 cm subcapsular collection on the left kidney compressing underlying parenchyma. Percutaneous drainage was not feasible because of severe curvature of spine. Isotope renogram revealed deterioration in left renal function from 30% to 17%. Follow-up CT revealed reduction in the size of subcapsular hematoma, no hydronephrosis, and several residual calculi.

Conclusion

Risk of subcapsular hematoma following ureteroscopic lithotripsy can be reduced by avoiding prolonged endoscopy and performing ureteroscopy under low pressure. When a paraplegic patient develops features of infection after ureteroscopy, renal imaging should be carried out promptly. Extended perioperative medical care is required for spinal cord injury patients because of their propensity to develop sepsis. Antibiotics should be prescribed on the basis of recent urine microbiology results. Spinal cord injury patients should be treated by senior, experienced doctors and cared for in a spinal injuries unit in order to minimize complications.

Subcapsular renal hematoma after ureteroscopy with holmium:yttrium-aluminum-garnet laser lithotripsy

Subcapsular renal hematoma (SRH) after ureteroscopic lithotripsy (URSL) using holmium:yttrium-aluminum-garnet (Ho:YAG) laser to treat ureteric stones is a rare complication. We aimed to review our unit's experience of post-URSL subcapsular renal hematoma. From 2006 to 2012, 2059 URSLs using F9.5 rigid ureteroscope were performed in our unit. Patients with post-URSL symptomatic renal hematoma were reviewed. Perioperative information on patients' renal function, stone characteristics, and degree of renal hydronephrosis were reviewed. Operative data, postoperative information such as clinical manifestation, changes in blood parameters, CT findings, and subsequent treatment were documented. Of the 2059 patients treated with URSL and Ho:YAG laser, three patients were diagnosed as subcapsular renal hematoma after surgery; the age is 57, 61, and 63 years old, respectively. Preoperative imaging examination showed that two patients and one patient had obstructing middle and proximal ureteral stones ranging in size from 0.8 to 1.6 cm, and three patients had thin renal cortices. The double-J ureteral stents were inserted in all cases regularly. All three subcapsular renal hematoma patients had the loin pain of the operation side and fever, and one patient had significant hemoglobin drop (from 111 to 61 g/L) who need to transfusion. Two patients presented within 24 h of URSL, and one patient presented on day 10. One patient was treated conservatively for 3 weeks and recovered with bed rest, antibiotics, hemostasis, and analgesia with no intervention or drain. The other two patients underwent ultrasonography-guided drainage of the hematoma. Two-month follow-up CT scans or ultrasonography confirmed the resolution of the hematoma in all three cases. Renal subcapsular hematoma after URSL is a rare and one of serious complications. Subcapsular renal hematoma should be considered when patients have the symptoms of significant loin pain after URSL for obstructing ureteral stones with thin renal cortices. The treatment of post-URSL renal subcapsular hematomas needs to be customized for each patient.

Subcapsular hematoma after ureteroscopy and laser lithotripsy

BACKGROUND AND PURPOSE

Renal hematoma after ureteroscopic lithotripsy (URSL) using holmium:yttrium-aluminum-garnet (Ho:YAG) laser is a rare complication. We aimed to review our center's experience of post-URSL subcapsular hematoma.

PATIENTS AND METHODS

From 2007 to 2012, 1114 URSLs using 7.5F semi-rigid ureteroscopes were performed. Patients with post-URSL symptomatic renal hematoma were reviewed. Perioperative information on patients' preoperative morbidity, renal function, stone characteristics, and degree of hydronephrosis were reviewed. Operative information, postoperative presentation of symptoms, changes in blood parameters, CT findings, and subsequent management were documented.

RESULTS

Post-URSL subcapsular hematoma was diagnosed in 4 of 1114 (0.36%) patients, who ranged in age from 43 to 63 years. Preoperative imaging showed that all four patients had obstructing proximal ureteral stones ranging in size from 0.7 to 2.1 cm, and three of them had thin renal cortices. Pressure bags were not used, and Double-J ureteral stents were inserted in all cases. All four patients had the triad of loin pain, fever, and significant hemoglobin drop necessitating transfusion. Three patients presented within 2 days of URSL, and one patient presented on day 20. One patient was treated conservatively and recovered with bed rest and antibiotics. Urgent angiography was performed on one patient in view of a significant drop in hemoglobin, but no embolization was needed. One patient underwent ultrasonography-guided drainage of the hematoma, and another had an emergency open clot evacuation because of significant compression on the kidney by the hematoma. Follow-up CT scans confirmed the resolution of the hematoma in all cases.

CONCLUSIONS

Post-URSL subcapsular hematoma is a rare but potentially serious complication. A high index of suspicion is needed when patients present with significant loin pain and fever after URSL for obstructing proximal ureteral stones with thin renal cortices. The management of post-URSL subcapsular hematomas needs to be customized for each patient.

New experimental models of diabetic nephropathy in mice models of type 2 diabetes: efforts to replicate human nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. The use of experimental models of DN has provided valuable information regarding many aspects of DN, including pathophysiology, progression, implicated genes, and new therapeutic strategies. A large number of mouse models of diabetes have been identified and their kidney disease was characterized to various degrees. Most experimental models of type 2 DN are helpful in studying early stages of DN, but these models have not been able to reproduce the characteristic features of more advanced DN in humans such as nodules in the glomerular tuft or glomerulosclerosis. The generation of new experimental models of DN created by crossing, knockdown, or knockin of genes continues to provide improved tools for studying DN. These models provide an opportunity to search for new mechanisms involving the development of DN, but their shortcomings should be recognized as well. Moreover, it is important to recognize that the genetic background has a substantial effect on the susceptibility to diabetes and kidney disease development in the various models of diabetes.

Subcapsular renal haematoma after holmium:yttrium-aluminum-garnet laser ureterolithotripsy

OBJECTIVE

To report the incidence, risk factors, and outcomes of subcapsular renal haematoma (SRH) after ureteroscopic lithotripsy (URSL) using holmium:yttrium-aluminum-garnet (Ho:YAG) laser to treat ureteric stones.

PATIENTS AND METHODS

Prospective data from 2848 URSLs performed between January 2003 and September 2010 were retrospectively analysed. In all 11 patients were identified as having a SRH after URSL if they had persistent severe ipsilateral flank pain or a palpable mass within a day of surgery, or presented with radiographic evidence of a SRH. Risk factors for the development and course of the SRH were reported.

RESULTS

Of the 2848 consecutive patients treated with URSL using Ho:YAG laser, 11 (0.4%) developed a SRH after surgery. Patients who developed a SRH had larger stones (1.4 vs 0.9 cm, P < 0.001), more severe ipsilateral hydronephrosis (P < 0.001), longer operation duration (41 vs 33 min, P < 0.001), and higher perfusion pressure of hydraulic irrigation (176.8 vs 170.2 mmHg, P < 0.001) than patients who did not develop a SRH. Patient age, sex, body mass index, presence of diabetes mellitus, history of urolithiasis and hypertension, presence of multiple stones, stone location and flow rate of hydraulic irrigation were not statistically different in patients who did or did not develop a SRH. Most patients were managed conservatively, with no further intervention or with a flank drain, until the SRH resolved. Overall, in three patients the SRH resolved with no further intervention, six patients were treated with a drain only, and two patients had open surgery within a day of presenting with SRH.

CONCLUSIONS

The rate of development of SRH after URSL is very low. Most patients who present with a SRH after URSL, can be treated conservatively with no intervention or with a drain only.

Cardiac and renal function are progressively impaired with aging in Zucker diabetic fatty type II diabetic rats

This study investigated the temporal relationship between cardiomyopathy and renal pathology in the type II diabetic Zucker diabetic fatty (ZDF) rat. We hypothesized that changes in renal function will precede the development of cardiac dysfunction in the ZDF rat. Animals (10 weeks old) were divided into four experimental groups: Lean Control (fa/?) LC (n = 7), untreated ZDF rats (n = 7) sacrificed at 16 weeks of age, and LC (n = 7) untreated ZDF rats (n = 9) sacrificed at 36 weeks of age. LV structural/functional parameters were assessed via Millar conductance catheter. Renal function was evaluated via markers of proteinuria and evidence of hydronephrosis. LV mass was significantly less in the ZDF groups at both time points compared to age-matched LC. End diastolic volume was increased by 16% at 16 weeks and by 37% at 36 weeks of age (p < 0.05 vs. LC). End diastolic pressure and end systolic volume were significantly increased (42% and 27% respectively) at 36 weeks of age in the ZDF compared to LC. Kidney weights were significantly increased at both 16 and 36 week in ZDF animals (p < 0.05 vs. LC). Increased urinary albumin and decreased urinary creatinine were paralleled by a marked progression in the severity of hydronephrosis from 16 to 36 weeks of age in the ZDF group. In summary, there is evidence of progressive structural and functional changes in both the heart and kidney, starting as early as 16 weeks, without evidence that one pathology precedes or causes the other in the ZDF model of type II diabetes.

Quantitative assessments of cerebral vascular damage with a silicon rubber casting method in photochemically-induced thrombotic stroke rat models

Previous studies have described microvascular disturbances downstream of occluded large vessels arising during the acute phase (several hours) following cerebral ischemic insult. Prolonged microvascular disturbances may cause delayed neuronal cell death in ischemic penumbral regions, leading to expanded brain infarctions and poor neurological and functional outcomes. The lack of simple and quantitative methods for investigating this microcirculation failure suggests the need to develop a new method for clarifying the precise distribution and persistence of post-ischemic microvascular disturbances. The present study used a silicone rubber casting method in quantitative analyses of microvascular conditions in photochemically-induced thromboembolic (PIT) stroke rat models. After the casting procedure in rats with PIT stroke, a 6 microm-thick coronal section was obtained, and quantitative analyses of microvascular density and measurements of the infarct area in the serial section were performed. The major findings of the present study are as follows: (1) Silicone rubber casting techniques can be applied to precise quantitative analyses of microvessels in the same individual in whom brain infarct volume was measured; (2) the persistence and spatial distribution of microvascular disturbances assessed at the ischemic core, ischemic penumbra, and non-ischemic regions strongly suggest that microvascular disturbances affect brain infarct expansion; (3) the current method demonstrated the protective effects of MK-801 on microvessels, indicating that the technique may be useful in investigating factors that provide vascular protection. The experimental procedure introduced here would facilitate future evaluations of vascular protective agents.

Animal models of obesity-associated chronic kidney disease

Dramatic advances in basic science have been made in the past 50 years on the basis of animal models of obesity and type II diabetes. Positional-cloning strategies in rodents with spontaneous obesity have enabled landmark scientific breakthroughs and defined the molecular scaffolding for the regulation of energy homeostasis. Recently, studies in the general population suggest that obesity is an independent risk factor for chronic kidney disease. To date, most of the animal studies that investigated chronic kidney disease associated with obesity and type II diabetes have largely been descriptive. We aim to provide an overview of animal models used to investigate the mechanisms of obesity-associated chronic kidney disease. Our overview is not meant to be an exhaustive list of all animal models in the literature on this subject, but rather to illustrate the experimental approaches. Because of space limitations, we have chosen to concentrate on rodent models. These animal models will provide excellent tools for in vivo testing of molecular mechanisms. Further hypothesis-driven research into the mechanism of chronic kidney disease and their progression by use of these models will provide important insights necessary to develop therapeutic strategies for this significant complication of the worldwide epidemic of obesity and type II diabetes.

Diabetic nephropathy: of mice and men

Accumulating evidence supports intrinsic genetic susceptibility as an important variable in the progression of diabetic nephropathy in people. Mice provide an experimental platform of unparalleled power for dissecting the genetics of mammalian diseases; however, phenotypic analysis of diabetic mice lags behind that already established for humans. Standardized benchmarks of hyperglycemia, albuminuria, and measurements of renal failure remain to be developed for different inbred strains of mice. The most glaring deficiency has been the lack of a diabetic mouse model that develops progressively worsening renal insufficiency, the sine qua non of diabetic nephropathy in humans. Differences in susceptibility of these inbred strains to complications of diabetes mellitus provide a possible avenue to dissect the genetic basis of diabetic nephropathy; however, the identification of those strains and/or mutants most susceptible to renal injury from diabetes mellitus is lacking. Identification of a mouse model that faithfully mirrors the pathogenesis of DN in humans will undoubtedly facilitate the development of new diagnostic and therapeutic interventions.

Mouse models of diabetic nephropathy

Mice provide an experimental model of unparalleled flexibility for studying mammalian diseases. Inbred strains of mice exhibit substantial differences in their susceptibility to the renal complications of diabetes. Much remains to be established regarding the course of diabetic nephropathy (DN) in mice as well as defining those strains and/or mutants that are most susceptible to renal injury from diabetes. Through the use of the unique genetic reagents available in mice (including knockouts and transgenics), the validation of a mouse model reproducing human DN should significantly facilitate the understanding of the underlying genetic mechanisms that contribute to the development of DN. Establishment of an authentic mouse model of DN will undoubtedly facilitate testing of translational diagnostic and therapeutic interventions in mice before testing in humans.

Losartan ameliorates progression of glomerular structural changes in diabetic KKAy mice

Pathological changes in glomerular structure are typically associated with the progression of diabetic nephropathy. The involvement of angiotensin II (AII) in pathogenesis of diabetic nephropathy has been extensively studied and the therapeutic advantages associated with blockade of renin-angiotensin system (RAS), primarily with angiotensin converting enzyme (ACE) inhibitors, has been well-documented. We studied the effect of RAS blockade with an AII receptor antagonist (losartan) vs. an ACE inhibitor (enalapril) on glomerular lesions in KKAy mice, a model of type 2 diabetes mellitus. Losartan was administered at 3 and 10 mg/kg/day and enalapril at 3 mg/kg/day for 14 weeks in the drinking water. The doses of losartan at 10 mg/kg/day was expected to be equivalent to 3 mg/kg/day of enalapril when considering clinical doses for lowering blood pressure. The dose of 3 mg/kg/day of losartan was selected to compare the efficacy at equivalent dose of enalapril. Histologic observation demonstrated suppression of glomerular mesangial expansion and glomerulosclerosis with exudative lesion in the 10 mg/kg/day losartan group when compared to the untreated diabetic controls. A lesser degree of glomerulosclerosis was also observed with losartan and enalapril treatment at 3 mg/kg/day. Ultrastructural examination of renal glomeruli from the high dose losartan group revealed a decreased degree of effacement and/or irregular arrangement of glomerular podocytic foot process. The beneficial effect of RAS inhibition with the AII receptor antagonist losartan on diabetic glomerular lesions was clearly demonstrated in this study. These findings, therefore, provide mechanistic explanation for the clinical utility of losartan for use in the treatment of diabetic nephropathy in man.