Development and external validation of a nomogram for predicting renal function based on preoperative data from in-hospital patients with simple renal cysts

Objective

To develop and validate a nomogram for predicting renal dysfunction in patients with simple renal cysts (SRCs).

Methods

We performed a multivariable logistic regression analysis of an in-hospital retrospective cohort of patients with SRCs in the Urology Department of the First Affiliated Hospital of Anhui Medical University. For prognostic model development, 386 patients with SRCs were enrolled from January 2016 to December 2018. External validation was performed in 46 patients with SRCs from January 2019 to April 2019. The primary outcome was renal dysfunction.

Results

Patients were divided into normal or abnormal estimated glomerular filtration rate groups (293 vs. 93) based on the cut-off value of 90 mL/minute/1.73 m². Logistical regression analysis determined that age, haemoglobin, globulin, and creatinine might be associated with renal dysfunction, and a novel nomogram was established. Calibration curves showed that the true prediction rate was 77.42%, and decision curve analysis revealed that the nomogram was more effective with threshold probabilities ranging from 0.1 to 0.8. The area under the curves were 0.829, 0.752, and 0.888 in the overall training, internal, and external validation cohorts, respectively.

Conclusions

We established a nomogram to predict the probability of developing renal dysfunction in patients with SRCs.

Retrospective Evaluation of the Clinical Values of Minimally Invasive Marsupialization of Symptomatic Giant Renal Cysts

Background: To evaluate the indication and benefit of minimally invasive laparoscopic marsupialization (MIS) of symptomatic giant renal cysts. Materials and Methods: Sixty-four consecutive patients who underwent MIS for large renal cysts (Bosniak I; 4 × 5-16 × 12 cm) by one surgeon were included in the study. Presenting symptoms were renal pain (100%), associated with hypertension (28%), renal dysfunction (4.7%), hematuria (4.7%), ureteropelvic junction obstruction (UPJO) (7.8%), ipsilateral urolithiasis (4.7%), polycystic kidney (6.3%), adrenal cyst (1.6%), and retroperitoneal cysts (1.6%). Seven patients with peripelvic cysts and previous retroperitoneal operations were treated by a laparoscopic approach; all other patients underwent retroperitoneoscopic marsupialization. Single-port retroperitoneoscopy was performed in 4 patients. Follow-up included clinical examination, abdominal ultrasound, and computed tomography scan. Postoperative radiologic success was defined as a minimum of 50% in size reduction and no recurrence. Results: Mean patients' age was 46 (21-65) years. All procedures were successfully completed without conversion or revision. Mean operative time was 55 (40-85) minutes with a mean hospital stay of 3 days. All patients underwent uneventful postoperative recovery. Observed minor complications (transitory fever/pain) were found in 4 patients during the first postoperative month. Median follow-up was 12 months (10 months-2 years). About 98.5% of patients reported of no relevant postoperative pain. A relief from UPJO and hematuria was achieved in 100% of patients. Ten patients with known hypertensive disease (55.6%) had a significant reduction of mean blood pressure resulting in a reduction of antihypertensive medication. Ureterorenoscopic stone extractions were performed successfully afterward. No cyst recurrences were detected during the follow-up period. Conclusion: Treatment indications for symptomatic renal cysts could include not only symptoms but also associated diseases like UPJO and hypertension. Retroperitoneoscopic MIS may be curative for these cyst-associated pathologies. The feasibility, safety and efficacy of these techniques could be demonstrated.

Percutaneous intrarenal cyst marsupialization and simultaneous nephrolithotomy in selected patients: killing two birds with one stone?

OBJECTIVE

To assess the safety, feasibility, and efficacy of percutaneous intrarenal cyst marsupialization and simultaneous nephrolithotomy in the management of a renal cyst with ipsilateral calculi in selected patients.

MATERIALS AND METHODS

Between July 2010 and August 2013, 16 patients (11 men and 5 women; mean age, 51 years) with a solitary posterior or parapelvic renal cyst and ipsilateral calculi underwent percutaneous intrarenal cyst marsupialization and simultaneous nephrolithotomy in our center. Mean cyst size was 6.3 cm (range, 4.2-11.8 cm). Mean stone surface area was 5.8 cm(2) (range, 1.8-12.1 cm(2)). By preoperative computed tomography planning and interoperative ultrasound guidance, the optimal puncture route was selected carefully to marsupialize the cyst and approach the target calyx. The cyst was marsupialized into the collecting system at the dilation process. Subsequently, percutaneous nephrolithotomy was performed in a standard fashion.

RESULTS

The mean operative time was 68 minutes (range, 47-93 minutes), and the mean hospital stay was 4 days (range, 3-7 days). A nephrostomy tube and a double-J stent were placed for a prolonged period to ensure the channel remained opened. Nearly complete cyst regression and calculi clearance confirmed by postoperative imaging was achieved in all patients. No intraoperative or postoperative complications in Clavien grading score ≥ 2 were noted during a mean follow-up of 21 months (range, 8-25 months).

CONCLUSION

In selected patients with a posterior or parapelvic renal cyst and ipsilateral calculi, the percutaneous technique is a safe and effective option through intermediate follow-up.

Management of a simple renal cyst in a complex patient

Renal cysts are generally classified as simple or complex and are further characterised under the Bosniak classification system. Most simple cysts are benign, asymptomatic and discovered incidentally. However, over time, these simple cysts can enlarge, become symptomatic and develop complications, requiring intervention. We present a case of a 70-year-old man with multiple comorbidities who presented with left lower quadrant abdominal pain and haematuria. An abdominal CT scan revealed a large, 26 cm exophytic cyst with high attenuation areas, septations and haemorrhage. Given the patient's tenuous condition and poor functional status, an interventional radiology-guided renal cyst aspiration was performed, resulting in successful reduction of size and symptom resolution. A follow-up ultrasound at 6 months showed no evidence of recurrence. Primary care providers should be aware of the prevalence of renal cysts and their complications, especially haemorrhage, particularly in high risk and elderly patients on anticoagulation or antiplatelet therapy.

Laparoscopic decortication of simple renal cyst with omental wadding technique: single-center experience

OBJECTIVE

What is the impact of the omental wadding technique on decreasing the incidence of recurrence after laparoscopic decortication of the symptomatic simple renal cyst? This is the question we are trying to answer through this study.

PATIENTS AND METHODS

This is a cohort study of 14 consecutive patients who underwent transperitoneal laparoscopic decortication of a symptomatic simple renal cyst with the omental wadding technique between November 2007 and November 2011. The indication for surgery was for relief of pain in all cases. Pain was assessed preoperatively and at 1 month and every 6 months postoperatively using a pain numerical rating scale. Only simple cysts (Bosniak I and II) more than 10 cm in their greatest dimension were included in this study. Patients with complicated cysts (Bosniak III and IV) and those with cysts less than 10 cm in their greatest dimension were excluded from this study. Patients were 7 men and 7 women with a mean age of 47 years (range, 35-63 years), and the mean body mass index was 27 kg/m(2). Laparoscopic decortication was the primary treatment in 11 cases and the secondary treatment in 3 cases after sclerotherapy. We used the omental wadding technique to try to fill the cavity after decortication to decrease the incidence of recurrence with simple laparoscopic decortication reported in other series. We reviewed the preoperative and postoperative data.

RESULTS

The operation was successfully completed laparoscopically in all cases with a mean operative time of 97 minutes without major perioperative complications. Hospital stay was 2.4 days (range, 2-4 days). All cases improved significantly after operation in a mean follow-up of 1.5 years. Using this technique, we did not have any recurrence after surgery.

CONCLUSIONS

Laparoscopic decortication with omental wadding is helpful to decrease the incidence of simple renal cyst recurrence after laparoscopic decortication.

Retroperitoneal laparoendoscopic single-site surgery in urology: initial experience

PURPOSE

To present our initial experience with single-port laparoscopic urologic surgery via the retroperitoneal approach using the Alexis wound retractor with flexible laparoscopic instrumentation.

PATIENTS AND METHODS

Since December 2008, 14 patients have undergone single-port laparoscopic surgery for various urological diseases, including renal cyst decortication in 5 patients, adrenalectomy in 2 patients, nephroureterectomy in 2 patients, nephrectomy in 3 patients, and ureterolithotomy in 2 patients. For the retroperitoneal approach, the Alexis wound retractor with a single port was used.

RESULTS

All cases were completed without conversion to standard laparoscopic or open surgery. The mean operative time and mean estimated blood loss for decortication of the renal cysts were 56 minutes (range 45-70 minutes) and 179 mL (range 22-398 mL), respectively; the mean operative time and mean estimated blood loss for extirpative or reconstructive surgery were 156 minutes (range 115-21 minutes) and 403 mL (range 35-1324 mL), respectively. The mean hospital stay was 6.5 days (range 4-14 days). There were no major intraoperative complications, but wound dehiscence and bleeding were noted in two patients.

CONCLUSION

Retroperitoneal single-port laparoscopic urologic surgery, particularly in patients requiring free-hand suturing, is technically feasible. The initial clinical experience of organ-ablative, extirpative, and reconstructive surgery with this approach is reported.