Reduced renal function in patients with simple renal cysts

BACKGROUND: Sporadic renal cysts not associated with genetic polycystic disorders are common and generally thought to be of no clinical significance. Since multiple cysts frequently develop in end-stage renal disease (ESRD), we tested the hypothesis that cysts that are solitary or few in number are an early manifestation of reduced renal function. METHODS: We evaluated 561 hospitalized patients who underwent contrast-enhanced, abdominal computed tomography (CT) and correlated clinical characteristics and parameters of renal function with the presence or absence of renal cysts. RESULTS: Age ranged from 16 to 100 years, mean serum creatinine concentration was 0.88 mg/dL (range 0.4 to 2.1 mg/dL), and mean estimated creatinine clearance was 94 mL/min/1.73 m(2) (range 22 to 218 mL/min/1.73 m(2)). The presence of cysts was significantly correlated with older age (P < 0.001), higher serum creatinine concentration (P < 0.002), and lower estimated creatinine clearance (P < 0.001). In a multivariate analysis, including age and gender, estimated creatinine clearance still correlated with the presence of cysts (P= 0.009). When patients were grouped by age, estimated creatinine clearance correlated with cysts in patients <40 years and 40 to 59 years, but not in patients 60 to 79 years or > or =80 years. There was no association of cysts with hypertension or proteinuria. In patients with cysts, serum creatinine increased progressively but not significantly with cyst number, and did not correlate with size or distribution of cysts. Renal parenchymal volume was slightly but not significantly reduced in patients with cysts. CONCLUSION: The presence of kidney cysts, even single cysts, is associated with reduced renal function in hospitalized patients younger than 60 years. This relationship may be obscured by the reduced renal function and the high incidence of cysts in older patients. These results suggest that acquired cystic kidney disease may begin early in the course of renal disease and that underlying renal disease should be considered in individuals with renal cysts prior to age 60 years.     

Reduced kidney size in patients with simple renal cysts

BACKGROUND: Renal cysts frequently occur in the absence of genetic diseases but their significance is unknown. Since multiple cysts develop in many patients with advanced renal disease, we tested the hypothesis that isolated cysts are associated with early nephron loss. METHODS: All inpatient and outpatient sonograms performed by the Renal Division since 1995 were reviewed and, after exclusion of duplicate studies, patients with genetic cystic disorders, complex cysts, hydronephrosis, peripelvic cysts, end-stage renal disease and transplanted kidneys, 2526 were selected for this study, of which 385 had one or more cysts. Maximum renal length was used as an indication of size, and renal function was estimated by serum creatinine concentration. RESULTS: Both right and left kidney length were significantly less in patients with cysts (P < 0.0001), independent of which kidney contained the cyst(s). Renal lengths were less in patients with multiple cysts as opposed to single cysts but not in patients with bilateral cysts as compared to unilateral cysts. Cysts were twice as frequent in solitary kidneys than in dual kidneys (P = 0.01). In outpatients matched for age and gender, those with cysts had a higher serum creatinine concentration but with borderline significance (P = 0.06). Multivariate analysis revealed that age, gender, and renal length were each independent variables and together accounted for one third of the incidence of cysts. CONCLUSION: Kidney size is reduced in patients with simple renal cysts noted on renal sonography, and cysts may be associated with reduced renal function. This suggests that isolated cysts are an indication of nephron loss in patients with renal abnormalities.     

腹腔镜治疗肾囊肿16例

目的 探讨腹腔镜手术治疗单纯性肾囊肿疗效。方法 采用经腹腔和经腹膜后腹腔镜技术对16例单纯性肾囊肿行囊肿去顶术,并回顾分析比较20例开放性肾囊肿去顶术。结果 经腹腔途径手术时间与开放手术无显著性差异(P>0.05),经腹膜后途径手术时间显著长于开放手术(P<0.05),腹腔镜手术患者的术中失血量、术后并发症及术后住院时间均显著少于开放手术(P<0.01)。结论 腹腔镜肾囊肿去顶术具有创伤小、术后并发症少及康复快等优点,治疗单纯性肾囊肿的疗效明显优于开放性手术。     

Long-term renal function in living kidney donors with simple renal cysts: A retrospective cohort study

Simple (Bosniak I) renal cysts are considered acceptable in living kidney donor selection in terms of cancer risk. However, they tend to increase in number and size over time and might compromise renal function in donors. To clarify their implications for long-term renal function, we characterized the prevalence of renal cysts in 454 individuals who donated at our center from 2000 to 2007. We estimated the association between the presence of cysts in the kidney remaining after nephrectomy (ie, retained cysts) and postdonation eGFR trajectory using mixed-effects linear regression. Donors with retained cysts (N = 86) were older (P < .001) and had slightly lower predonation eGFR (median 94 vs 98 mL/min/1.73 m², P < .01) than those without cysts. Over a median 7.8 years, donors with retained cysts had lower baseline eGFR (_−8.7 −5.6 _−2.3 mL/min/1.73 m², P < .01) but similar yearly change in eGFR (_−0.4 0.02 _0.4 mL/min/1.73 m², P = .2) compared to those without retained cysts. Adjusting for predonation characteristics, there was no difference in baseline eGFR (P = .6) or yearly change in eGFR (P > .9). There continued to be no evidence of an association when we considered retained cyst(s) ≥10 mm or multiple retained cysts (all P > .05). These findings reaffirm current practices of accepting candidates with simple renal cysts for donor nephrectomy.     

小切口手术治疗单纯性肾囊肿

目的　探讨小切口手术治疗单纯性肾囊肿的特点及适应证。　方法　手术切口取第12肋尖下方做长约 3～ 4cm的小切口 ,对单纯肾囊肿患者行小切口囊肿去顶术 ,对手术方法、疗效及适应证进行分析。　结果　小切口手术组 19例 ,囊肿均位于肾下极及中部背侧 ,手术时间 2 0～ 80min(34± 15min) ,术后未发生并发症 ,住院日 3～ 8d(4 4± 1 5d)。随访 3～ 6个月均无复发。　结论小切口手术治疗单纯肾囊肿具有手术操作简便、创伤小、恢复快、降低住院日及医疗费用等优点 ,其适应证是肾下极、肾中部背侧的单纯肾囊肿。     

腹腔镜手术治疗肾囊肿23例疗效观察

目的 :探讨腹腔镜手术治疗单纯性肾囊肿的方法及疗效。方法 :通过经腹腔和经腹膜后两种途径 ,采用腹腔镜技术对 2 3例单纯性肾囊肿患者行囊肿去顶术 ,并与 9例行开放性肾囊肿去顶术的患者进行比较。结果 :经腹膜后途径手术的手术时间显著长于开放手术 (P <0 .0 5 ) ,经腹腔途径手术的手术时间与开放手术无显著性差异 (P >0 .0 5 ) ,腹腔镜手术患者的术中失血量及术后住院时间均显著少于开放手术 (P <0 .0 1)。结论 :腹腔镜手术是治疗单纯性肾囊肿创伤小、效果好的有效方法     

Management of simple renal cysts in children

Simple renal cysts are uncommon in children and their presentation and management has changed with increasing use of ultrasound scans. The aim of this study was to review our experience and highlight some peculiarities in diagnosis and management of these cases. Eight cases were diagnosed and two symptomatic cases underwent aspiration under ultrasound guidance; one case recurred and required re-aspiration. Differentiation of simple renal cysts from other cystic lesions of the kidney, aspiration of symptomatic cysts and the importance of long-term follow-up are discussed.     

Percutaneous injection sclerotherapy with tetracycline hydrochloride in simple renal cysts

OBJECTIVES: Symptomatic simple renal cysts can be treated by combination of percutaneous aspiration and sclerotherapy. A number of sclerosing agents including glucose, phenol, iophendylate, polidocanol, minocycline and pantopaque have been used in the past to prevent reformation of cyst. In this study, tetracycline HCL solution is evaluated as a sclerosant for treatment of simple renal cysts. METHODS: Our study treated 76 cysts in 70 patients with symptomatic renal cysts. Aspiration and sclerotherapy was performed on 56 cysts, and 20 cysts aspirated without sclerotherapy as a control group. Treatment was performed under local anesthesia and punctured under ultrasound guidances with an 18-gauge needle. Tetracycline HCL (20%) was injected into the cystic cavity according to cyst diameter. All patients were followed up with an ultrasound examination at 3 months, 6 months, and then at yearly intervals. The reduction rate was estimated by a comparison of the volume of the cyst before and after treatment. A cyst reduction of 50% or greater in diamater was considered as a successful treatment. RESULTS: The average follow-up period was 9.8 months in the sclerotherapy group and 9.9 months in the control group. The success rate was 85.7% in the sclerotherapy group. There was a significant difference in the reduction rate of tetracycline HCL sclerotherapy group and control group. No major complications were encountered.     

Laparoscopic management of symptomatic simple renal cysts

Objective: To evaluate the efficacy of retroperitoneoscopy for the treatment of symptomatic renal cyst disease. Patients and methods: We evaluated the efficacy and morbidity of aspiration versus open and laparoscopic surgical techniques in a paired institution over a 20-year period. Prospectively recorded parameters for the 11 cases dealt with by primary retroperitoneoscopic techniques were compared with historical controls dealt with by open surgery. Results: Small volume cysts were satisfactorily dealt with by aspiration alone. All patients undergoing laparoscopic cyst decortication for the larger volume cysts had a satisfactory outcome with improvement in their symptoms and objective cure on follow up imaging studies. Conclusion: Laparoscopic management for all cysts is a safe, effective and minimally invasive alternative to open surgery for symptomatic renal cysts. Simple drainage under radiological guidance is also highly effective and should probably be first line treatment for cysts up to 6 cms in diameter whereas primary laparoscopic treatment should be suggested for larger cysts. This revised version was published online in August 2006 with corrections to the Cover Date.     

Percutaneous injection sclerotherapy with minocycline hydrochloride for simple renal cysts

Minocycline hydrochloride as a sclerosant for the treatment of simple renal cysts was evaluated. Cyst puncture was performed, and minocycline hydrochloride solution for intravenous administration was injected after aspiration. Of 154 cysts evaluated by ultrasound after 3 months or more, 69 were no longer demonstrable, 49 showed 50% or greater reduction in the maximum cyst diameter, and only 8 were unchanged or slightly increased in size. In constrast, only 1 of 20 cysts aspirated without minocycline hydrochloride injection (controls) showed 50% or greater reduction after 3 months. There was a significant difference in the reduction rates between the minocycline-treated group and control group (p<0.01). These results suggest that minocycline hydrochloride is an effective sclerosant to treat simple renal cysts.     

The natural history of simple renal cysts.

PURPOSE: Although simple renal cysts are common in older patients, little is known concerning their natural history. We examined the natural history of renal cysts by investigating the prevalence and sequential changes in their size and number in individuals. MATERIALS AND METHODS: We collected data on 14,314 individuals who participated in a multiphasic health screening program at our institute in 1999. An ultrasound renal cyst prevalence survey was performed. As a longitudinal study, 45 patients with renal cysts were followed a mean of 6 years from January 1993 to December 1999. RESULTS: In the prevalence survey 1,700 individuals (11.9%) had at least 1 renal cyst on ultrasound. The ratio of men-to-women with cysts was 2:1. The prevalence of renal cysts increased more than 7-fold with age from 5.1% in the fourth to 36.1% in the eighth decade of life. Our longitudinal study revealed that the majority of cysts increased in size and number. The average increase in size and the rate of enlargement were 2.82 mm. and 6.3% yearly, respectively. Cysts in patients younger than 50 years grew more rapidly than those in patients 50 years old and older, at a rate of 3.94 and 1.84 mm. yearly, respectively (p = 0.010). Multiloculated cysts progressed more rapidly than simple cysts (6.93 versus 2.18 mm. yearly, p <0.0001). CONCLUSIONS: The prevalence of renal cysts increases with age and shows a remarkable difference in incidence by sex. Renal cysts progress in size and number, and appear to grow more rapidly in younger patients. The natural history of multiloculated cysts may be distinct from that of simple cysts and warrants further investigation.     

Management of simple renal cysts during percutaneous nephrostolithotomy

Simple renal cysts can coexist with renal stones. Percutaneous removal of these stones requires special considerations. We describe the management of 2 patients with this problem and propose a simple logarithm.     

On the pathogenesis of simple renal cysts in the adult

Summary The simple cyst in the adult seems to be mainly an acquired disorder. Microdissection of the nephron in the adult kidney points to the presence of diverticula on the distal tubule as the starting point of the affection. A degree of obstruction in the urinary tract together with normal involutional phenomena of the basal membrane, both typical of the aging process, are believed to be precipitating factors.     

A clinical view of simple and complex renal cysts

The availability and use of abdominal diagnostic ultrasonography or computed tomography has led to the frequent detection of asymptomatic renal cysts. The vast majority of these are simple cysts that are usually unilateral and solitary with well-defined structural and imaging features and whose occurrence, number, and bilaterality increase with age. Simple cysts are asymptomatic, except when complications such as hemorrhage, infection, or rupture lead to the development of complex cysts with calcification, demarcation irregularities, and multilobularity. The diagnostic challenges that cysts present are in the differentiation of the less common complicated complex cysts from those associated with malignancy and when numerous the possible heralding of genetic or acquired multicystic diseases of the kidney.