Renal parenchymal disease: histopathologic-sonographic correlation

Retrospective study of 60 patients with histologically confirmed renal parenchymal disease and ultrasound examination of kidneys was conducted at King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia. The various renal parenchymal abnormalities were: proliferative glomerulonephritis (26 cases), glomerulosclerosis and focal segmental glomerulonephritis (5 cases), membranous glomerulonephritis (7 cases), minimal changes (12 cases), sclerosing glomerulonephritis (3 cases), chronic interstitial nephritis (2 cases), mesangiocapillary glomerulonephritis (2 cases), amyloidosis (1 case), Wilson's disease (1 case), and medullary cystic disease (1 case). Ultrasound examination was normal in 31 cases (51% of 60 cases) and abnormal in the rest of the cases. Thus, there was no correlation among the specific type of renal disease, cortical echogenicity and corticomedullary definition.     

Renal parenchymal carcinoma in children

A series of 14 cases of renal parenchymal carcinoma in patients under 20 years of age is presented and reviewed with the best documented case reports from the literature. Unlike its adult counterpart the tumour has an equal sex ratio and minor trauma frequently precipitates presentation, otherwise its behaviour is similar. The treatment of choice is nephrectomy but, unlike adults, there is evidence to support the value of adjunctive radiotherapy and chemotherapy in the treatment of local spread. Prognosis is particularly worsened by cellular granularity, and vascular or direct extrarenal spread. The 5 year survival rate is 52 per cent.     

Renal parenchymal neurilemoma: a rare and unusual kidney tumor

We report a case of a neurilemoma arising from the renal parenchyma. Renal neurilemoma is an extremely rare tumor, with only 5 cases previously reported. Because so little is known of its natural history and potential for malignancy we recommend radical nephrectomy as the treatment of choice.     

High-pressure fibrin sealant foam: an effective hemostatic agent for treating severe parenchymal hemorrhage

BACKGROUND: The majority of early trauma deaths are related to uncontrolled, noncompressible, parenchymal hemorrhage from truncal injuries. The purpose of this study was to formulate a fibrin sealant foam (FSF) able to control severe parenchymal bleeding without compression or vascular control. MATERIALS AND METHODS: FSF with high fibrinogen concentration (20 mg/mL) and low thrombin activity (5 U/mL) was prepared and pressurized by addition of liquid gas propellant. The efficacy of this foam was tested against a severe parenchymal hemorrhage, created by partial resection of liver lobes in anticoagulated rabbits (n = 7) and compared to untreated injury (n = 8) and placebo treatment (n = 7). The hemostatic efficacy of pressurized FSF (n = 8) was also compared to a commercially available liquid fibrin sealant (n = 8) and a developing dry powdered fibrin sealant product (n = 8) in the same model. RESULTS: The liver injury resulted in 122 +/- 11.5 mL blood loss and death of 75% of untreated rabbits (3.2-3.4 kg) within 1 h. Treatment with placebo foam had no effect on blood loss or mortality rate. Pressurized FSF significantly reduced bleeding, resulting in 56% (P < 0.05) and 66% (P < 0.01) reduction in blood loss as compared to untreated or placebo-treated animals, respectively, and 100% survival (P = 0.008). When pressurized FSF was compared with liquid and powdered forms of fibrin sealant, only foam significantly reduced blood loss (49%, P < 0.05) and mortality rate (54%, P < 0.05) of rabbits as compared to untreated control animals (n = 9). CONCLUSION: Biological nature, rapid preparation, coverage of large wound areas, and effective hemostatic properties make pressurized FSF an ideal candidate for treating nonoperable parenchymal injuries in damage control procedures.     

Renal parenchymal injury after standard and mini percutaneous nephrostolithotomy

PURPOSE: Mini percutaneous nephrostolithotomy was developed for use in children and in adults with a reduced renal reserve to minimize the morbidity and renal parenchymal damage presumed to occur with traditional percutaneous nephrostolithotomy. We compared the extent of renal injury incurred by different sized nephrostomy tracts in female farm pigs undergoing 11 or 30Fr percutaneous nephrostomy. MATERIALS AND METHODS: Bilateral percutaneous nephrostomy was attempted via a mid or lower pole calix under fluoroscopic guidance in 6 pigs. In 2 pigs the procedure was unsuccessful on 1 side, leaving 5 successfully established nephrostomy tracts on each side. In each pig the right percutaneous tract was dilated with a 28Fr dilating balloon and a 30Fr Amplatz working sheath (Cook Urological, Spencer, Indiana) was positioned in the collecting system. On the left side an 11Fr sheath (Cook Urological) was placed. The sheaths were removed after 1 hour and nephrostomy tubes (22Fr on the right and 8Fr on the left side) were left in place overnight and then removed. Six weeks later the pigs were sacrificed and the kidneys were harvested. The nephrostomy tracts were identified grossly and examined microscopically, and the fibrotic scar was measured using digital analysis. The volume of scar was estimated using the calculated volume of a cylinder. RESULTS: At kidney harvest all 10 kidneys appeared grossly normal. No intra-abdominal urine collection or perirenal hematoma was noted. Mean estimated scar volume of the 30 and 11Fr tracts was 0.29 and 0.40 cc, which translates into a mean fractional loss of parenchyma of 0.63% and 0.91%, respectively (p not significant). CONCLUSIONS: Renal parenchymal damage resulting from the creation of a nephrostomy tract is small compared to overall renal volume regardless of the size of the nephrostomy tract. Consequently there is no advantage to the use of a small access sheath based on renal scarring alone.     

Renal parenchymal damage on DMSA-scintigraphy in pelviureteric obstruction

During a 1.5 year period 21 children were investigated with 99-m-technetium dimercaptosuccinic acid (DMSA) before operation for hydronephrosis due to pelviureteric obstruction. The age at investigation was 0.2-11.5 years. Fourty-two kidneys were examined. Hydronephrosis existed on the right side in 8 cases, left side in 9 and bilateral in 4 cases. Seventeen kidneys had no obstruction. The scintigraphy was interpreted as normal in 19 kidneys. Decreased isotope uptake was found in 23 kidneys and localized to the upper pole area in 19 kidneys, middle-lateral part in 7, lower pole area in 15 and the middle-medial part in 12 kidneys. There were no predominance for any part of the kidney to be affected by parenchymal damage. In 8 children investigated before the age of 1 year, 4 of 10 hydronephrotic kidneys revealed normal DMSA scintigram. DMSA scintigraphy delineates functioning renal parenchyma. DMSA scintigraphy delineates functioning renal parenchyma. It can be recommended as a routine method for evaluation of the renal parenchyma before surgery and for follow up studies in all ages of childhood.     

Renal parenchymal appearance on 123iodine-hippurate renoscintigrams and excretory urograms

In 61 patients with vesicoureteral reflux renal scar formation was diagnosed by excretory urography and 123iodine-hippurate scintigrams. Scar formation on the nephrograms was detected in the upper, middle and lower zones of the kidneys on tomography exposures. Scintigraphic detection of scars was performed on the computerized uptake of the parenchymal phase. Maximal time elapse between the 2 investigations was 1 year. Excretory urography revealed 37 kidneys with a total of 74 regional scars. On scintigraphy 57 kidneys were judged to have 102 scars. There were 281 regions judged to be identical on the scintigram and the nephrogram. A true positive ratio (sensitivity) of 0.46 and a true negative ratio (specificity) of 0.90 were noted for the excretory urogram, compared to a sensitivity of 0.64 and a specificity of 0.81 for renography. The study confirms an over-representation of scars judged from scintigrams, which calls for further investigation of scar formation detection.     

Novel technique of knotless hemostatic renal parenchymal suture repair during laparoscopic partial nephrectomy

Free-hand parenchymal suturing during warm-ischemia, laparoscopic partial nephrectomy is a complex and time-sensitive task. We describe a relatively simpler technique of achieving renal parenchymal hemostasis during laparoscopic partial nephrectomy using a polymer self-locking (Hem-o-Lok) clip.     

Renal parenchymal volume increases after contralateral nephrectomy: assessment using three-dimensional ultrasonography

We investigated the relationship between changes in renal parenchymal volume (RPV) and renal function after a unilateral nephrectomy. In all 46 consecutive patients undergoing unilateral nephrectomy were included. Three-dimensional ultrasonography was performed before surgery (n=46) and at 4.3±1.9 h (n=46), 2 days (n=39), and 7 days (n=43) after surgery to determine RPV. The mean RPV of the remaining kidney was 104.7 mL before surgery, 116.1 mL (+13.2%) at 4.3 h, 122.7 mL (+18.2%) at 2 days, and 117.6 mL (+13.3%) at 7 days after surgery. Sequential volume measurements during surgery (n=5) revealed that the transection of the renal artery was followed by an increase in RPV on the contralateral side at 60-90 min. Multivariate regression analysis revealed that RPV was positively associated with the single-kidney glomerular filtration rate (GFR) and body surface area in both the preoperative and postoperative states. An increase in the single-kidney GFR was not seen at 2 years in patients with an RPV increase of <5% at 1 week (102.9±8.4%, P=0.322), but was still significant in the other patients (115.5±21.0%, P<0.001). These findings suggest that kidney volume may increase due to enlargement of the vascular bed caused by increased renal blood flow during the acute phase. Thereafter, histological hypertrophic responses may replace the hemodynamic changes in the chronic phase.     

Renal biopsy in congenital ureteropelvic junction obstruction: evidence for parenchymal maldevelopment

The renal histologic changes associated with congenital ureteropelvic junction obstruction (UPJO) and the relationship to clinical imaging have not been well studied. In order to better understand the histologic alterations of congenital UPJO and their relationship with clinical imaging and outcomes, we examined renal biopsies from 61 patients undergoing pyeloplasty for congenital UPJO. Glomeruli were analyzed for various injury patterns and the tubulointerstitium was examined for tubular atrophy/simplification and fibrosis. Two methods were used to evaluate tubular mass: glomerular density and morphometric measurement of tubular size and density. Control specimens were obtained from age-matched autopsy specimens without renal pathology. Glomerular changes were identified in 73% of all biopsies and were present in a range from 1.7 to 91% of glomeruli in each patient. Overt tubulointerstitial changes were present in 26% of all biopsies. Fibrosis was noted to occur with tubulointerstitial changes in a significantly greater fraction of children over the age of 1 year (P=0.026). Increased glomerular density was associated with severe hydronephrosis (P<0.02). Normal glomerular density was inversely correlated with age (P<0.001), but this relationship was more variable in UPJO (P<0.01). Among patients with intact differential function preoperatively (>45%), postoperative functional decline was predicted only by increased glomerular density. 20 biopsies without overt tubulointerstitial changes were analyzed morphometrically and showed a significant reduction in proximal tubular (PT) size, but unchanged density. Distal tubular (DT) size was unchanged in UPJO, but density was increased. The PT/DT ratio was therefore markedly decreased in UPJO (P<0.0001). Both PT and DT sizes were significantly larger in children with a diuretic renogram washout time less than 20 min than those with greater than 20 min, a common threshold for functionally significant obstruction (P<0.05). Capsular thickness was significantly increased in UPJO. In all, 36% of biopsies had a thickness >0.5 mm and this was associated with greater degrees of tubulointerstitial changes and glomerular alterations. Congenital UPJO produces a variety of renal parenchymal changes, which may in part reflect abnormal development. Some of these alternations are seen in clinical imaging and may help predict outcomes, but there is significant discordance between conventional imaging and histological findings.     

Fibrin sealants and glues

Fibrin sealants and fibrin glues have become effective instruments in the care of surgical patients. They have been used as an adjunct to hemostasis, wound healing, tissue adhesion, and drug delivery. In cardiac surgery, fibrin glues have emerged as valuable tools to improve hemostasis, decreased blood transfusions, improve tissue handling, and pretreat vascular grafts. Fibrin glues and sealants are now available commercially in the United States. This article will review the history, pharmacology, uses, and toxicity of fibrin sealants and fibrin glues.     

Renal parenchymal thickness in children with solitary functioning kidney

Background

Reduced renal parenchymal thickness (PT) is a parameter used by clinicians to assess the degree of hydronephrosis. In patients with a congenital hydronephrotic solitary functioning kidney (SFK), PT is difficult to determine as there is no comparison with the contralateral kidney. The aim of this study was to obtain ultrasound measurements of PT in children with normal SFK and to compare these data with PT measurements in children with two functioning kidneys.

Methods

This was a prospective multicenter study carried out between 2006 and 2011 in which 236 children aged 11 days to 18.96 years with healthy SFK were examined. The SFK etiologies were unilateral renal agenesis or a nonfunctioning contralateral kidney, mostly due to multicystic dysplasia. In addition to determining other parameters, we measured PT in the middle third of the kidney by ultrasound. Correlations between PT and age, height and weight were assessed.

Results

Correlation analysis showed a positive correlation with renal PT for all parameters. The correlation coefficients for age, height and weight were 0.863, 0.873 and 0.874, respectively. In most age categories, the renal parenchyma was significantly thicker in the SFK than in two functioning kidneys.

Conclusions

Based on our results, we suggest that PT in the SFK is correlated with height, weight and age of the patient. Consequently, measurements of PT may be used for monitoring the development of the healthy SFK and may contribute to a more accurate assessment of the severity of SFK anomalies.     

Tissue glues and nonsuturing techniques

PURPOSE OF REVIEW: This article details the diverse urologic applications of tissue glues and hemostatic agents over the past 3 years in the management of genitourinary injuries, surgical wounds, and complications. RECENT FINDINGS: Biosurgical agents designed to promote tissue adhesion and hemostasis are being increasingly employed across all surgical disciplines. Fibrin sealant is the most widely utilized biosurgical product. Gelatin matrix thrombin has proven to be an efficacious hemostatic agent. Bovine serum albumin-gluataraldehyde is a new, promising tissue glue. Complex reconstructive, oncologic and laparoscopic procedures are those most appropriate for sealant use in urology. SUMMARY: Tissue glues and hemostatic agents are effective, safe, and their use is increasing. All urologists should have a working knowledge of these adjuncts.     

Renal parenchymal malakoplakia —a case report and review of the literature

Malakoplakia is an inflammatory condition associated with persisting bacterial antigen in macrophages and characterised histologically by the Michaelis-Gutmann body, containing bacterial fragments. We review the pathogenesis of malakoplakia and report a novel form of treatment successfully used in an 8-week-old infant with bilateral renal malakoplakia. The patient presented with an acuteEscherichia coli urinary tract infection and enlarged kidneys. Antibiotic regimes were ineffective, but once the diagnosis was made treatment was changed to an immunosuppressive regime of prednisolone and azathioprine, to which she responded promptly. Renal malakoplakia should be considered in any patient with a urinary tract infection unresponsive to antibiotics and enlarged kidneys. Although a large proportion of patients with malakoplakia have an underlying systemic disorder, which may account for their abnormal macrophage function, the rest demonstrate either an isolated macrophage defect or no detectable anomaly at all. It is in this latter group we suggest that an immunomodulating regime can be curative.     

Renal parenchymal malacoplakia: a rare cause of ARF with a review of recent literature

Renal parenchymal malacoplakia is a rare cause of acute renal failure. Traditionally, it was associated with a high mortality rate and commonly resulted in renal failure requiring renal replacement therapy. The authors report on a 70-year-old woman who presented with acute renal failure caused by renal parenchymal malacoplakia. Her renal function recovered after levofloxacin treatment. All cases reported in the English-language literature since 1990, when fluoroquinolone was first used to treat malacoplakia, were reviewed. Although some patients still had renal failure, with renal biopsy and fluoroquinolone treatment, the patient mortality rate from renal parenchymal malacoplakia is remarkably low.     

Renal parenchymal hypoxia, hypoxia response and the progression of chronic kidney disease

Renal parenchymal hypoxia, documented under a variety of clinical conditions, conceivably contributes to the progression chronic kidney disease. In this review, normal physiologic medullary hypoxia and abnormal profiles of renal pO(2) in chronic kidney diseases are presented, and the mechanisms leading to anomalous renal tissue oxygenation are discussed. Direct measurements of pO(2) with oxygen electrodes, immunostaining with pimonidazole (which binds to regions with very low pO(2)), or the detection of hypoxia-inducible factor (HIF)-alpha (which accumulates in hypoxic regions, initiating hypoxia-adaptive responses), all serve to detect the distribution and extent of renal parenchymal hypoxia under experimental settings. The use of BOLD MRI as a noninvasive tool, detecting deoxygenated hemoglobin in hypoxic renal tissues, has evolved from experimental settings to human studies. All these modalities indicate that abnormal renal oxygenation develops under conditions such as chronic glomerular, tubulointerstitial or renovascular disease, in diabetes, hypertension, aging, renal hypertrophy, anemia or obstructive uropathy. Abnormal renal tissue hypoxia modifies the pattern of regional gene expression, evoking a host of adaptive and renoprotective pathways (such as HIF-mediated erythropoietin or heme-oxygenase-1), in parallel with the induction of potentially harmful mediators that participate in the progression of chronic kidney injury. Slowing the progression of chronic kidney disease may be achieved by a better understanding of these parallel processes and the accomplishment of a selective control of such protective and maladaptive responses.