Off-clamp Retroperitoneoscopic Tumour Evacuation for Sporadic Renal Angiomyolipomas with High RENAL Nephrometry Scores: A Novel Surgical Technique and Its Outcomes

Management of renal sinus angiomyolipoma: modified robotic nephron-sparing surgery in a single center

BACKGROUND

Renal sinus angiomyolipoma (RSAML) is a rare and typically complex renal tumor. The objective is to present our single-center experience with a modified technique of robotic nephron-sparing surgery (NSS) for treating RSAML.

METHODS

We retrospectively evaluated 15 patients with RSAMLs who were treated with robotic NSS at the Department of Urology of Tongji hospital, ranging from November 2018 to September 2022. Renal vessels and ureter were dissected. The outer part of RSAML was resected. The rest of tumor was removed by bluntly grasp, curettage and suction. Absorbable gelatin sponges were filled in the renal sinus. The preoperative parameters, operative measures and postoperative outcomes were all collected. Follow-up was performed by ultrasonography and estimated glomerular filtration rate (eGFR).

RESULTS

Robotic NSS was successfully performed in all the patients, without any conversion to open surgery or nephrectomy. The mean operation time was 134.13 ± 40.56 min. The mean warm ischemia time was 25.73 ± 3.28 min. The median estimated blood loss was 100 [50, 270] ml and 1 patient required blood transfusion. The mean drainage duration was 5.77 ± 1.98 days. The median postoperative hospital stay was 6.90 [5.80, 8.70] days. Two patients experienced postoperative urinary tract infection (Clavien-Dindo Grade II). During the median follow-up of 25.53 ± 15.28 months, patients received 91.18% renal function preservation. No local recurrence occurred in all the patients.

CONCLUSIONS

Robotic NSS for RSAML is a complicated procedure that demands technical expertise and a well-designed strategy is critical in the operation. Treating RSAML with modified robotic NSS is safe, effective and feasible.

The safety and effectiveness of laparoscopic off-clamp tumor evacuation versus traditional nephron-sparing surgery for large (>4 cm) sporadic renal angiomyolipomas

BACKGROUND

Off-clamp nephron-sparing surgery (NSS) have been selectively performed in renal tumors in which the majority are T1a (<4 cm) renal caners. Less is known, however, whether off-clamp is a safe and effective option for treatment of Sporadic Renal Angiomyolipomas (RAML), especially in those >4 cm. The objective of our study was to compare the perioperative and renal function outcomes of a novel off-clamp tumor evacuation technique versus conventional laparoscopic NSS for the treatment of large sporadic RAMLs (>4 cm).

METHODS

From January 2021 to June 2022, 42 patients diagnosed with RAML were prospectively randomized to receive laparoscopic standard NSS (Group 1) and off-clamp tumor evacuation (Group 2). The surgical and postoperative outcomes of both groups were compared.

RESULTS

Baseline characteristics demonstrated no discernible variation between Group 1 and Group 2. Compared to Group 1, Group 2 was associated shorter operative time (92.5 vs 82.3 min, p < 0.001), elimination of warm ischemic time (22.9 vs 0 min, p < 0.001), more blood loss (92.6 vs 161.9 ml, p = 0.02), and lower short-term renal function reduction of the operated kidney (17.2% vs 9%; p < 0.001). Neither major complication nor recurrence occurred.

CONCLUSION

It seems that transperitoneal laparoscopic off-clamp tumor evacuation is a feasible and safe option for the treatment of RAML, with the added benefit of preserving renal function to a greater extent than the traditional methods.

Distinguishing lipid-poor angiomyolipoma from renal carcinoma using tumor shape

OBJECTIVES

To validate the "overflowing beer sign" (OBS) for distinguishing between lipid-poor angiomyolipoma (AML) and renal cell carcinoma, and to determine whether it improves the detection of lipid-poor AML when added to the angular interface sign, a previously-validated morphologic feature associated with AML.

METHODS

Retrospective nested case-control study of all 134 AMLs in an institutional renal mass database matched 1:2 with 268 malignant renal masses from the same database. Cross-sectional imaging from each mass was reviewed and the presence of each sign was identified. A random selection of 60 masses (30 AML and 30 benign) was used to measure interobserver agreement.

RESULTS

Both signs were strongly associated with AML in the total population (OBS: OR 17.4 95% CI 8.0-42.5, p < 0.001; angular interface: OR 12.6, 95% CI 5.9-29.7, p < 0.001) and the population of patients excluding those with visible macroscopic fat (OBS: OR 11.2, 95% CI 4.8-28.7, p < 0.001; angular interface: 8.5, 95% CI 3.7-21.1, p < 0.001). In the lipid-poor population, the specificity of both signs was excellent (OBS: 95.6%, 95% CI 91.9%-98%; angular interface: 95.1%, 95% CI 91.3%-97.6%). Sensitivity was low for both signs (OBS: 31.4%, 95% CI 24.0-45.4%; angular interface: 30.5%, 95% CI 20.8%-41.6%). Both signs showed high levels of inter-rater agreement (OBS 90.0% 95% CI 80.5 - 95.9; angular interface 88.6, 95% CI 78.7-94.9) Testing for AML using the presence of either sign in this population improved sensitivity (39.0%, 95% CI 28.4%-50.4%, p = 0.023) without significantly reducing specificity (94.2%, 95% CI 90%-97%, p = 0.2) relative to the angular interface sign alone.

CONCLUSIONS

Recognition of the OBS increases the sensitivity of detection of lipid-poor AML without significantly reducing specificity.

Fat-poor renal angiomyolipoma with prominent cystic degeneration: A case report and review of the literature

BACKGROUND

Angiomyolipoma (AML), the most common benign tumor of the kidney, is usually composed of dysmorphic blood vessels, smooth muscle, and mature adipose tissue. To our knowledge, AML with cystic degeneration has rarely been documented. Cystic degeneration, hemorrhage, and a lack of fat bring great challenges to the diagnosis.

CASE SUMMARY

A 60-year-old man with hypertension presented with a 5-year history of cystic mass in his left kidney. He fell 2 mo ago. A preoperative computed tomography (CT) scan showed a mixed-density cystic lesion without macroscopic fat density, the size of which had increased compared with before, probably due to hemorrhage caused by a trauma. Radical nephrectomy was performed. Histopathological studies revealed that the lesion mainly consisted of tortuous, ectatic, and thick-walled blood vessels, mature adipose tissue, and smooth muscle-like spindle cells arranged around the abnormal blood vessels. The tumor cells exhibited positivity for human melanoma black-45, Melan-A, smooth muscle actin, calponin, S-100, and neuron-specific enolase, rather than estrogen receptor, progesterone receptor, CD68, and cytokeratin. The Ki-67 labeling index was less than 5%. The final diagnosis was a fat-poor renal AML (RAML) with prominent cystic degeneration.

CONCLUSION

When confronting a large renal cystic mass, RAML should be included in the differential diagnosis.

Are nephrometry scores accurate for the prediction of outcomes in patients with renal angiomyolipoma treated with robot-assisted partial nephrectomy? A multi-institutional analysis

BACKGROUND

Prediction of complications and surgical outcomes is of outmost importance even in patients with benign renal masses. The aim of our study is to test the PADUA, SPARE and R.E.N.A.L. scores to predict nephron sparing surgery (NSS) outcomes in patients presenting with renal angiomyolipoma (RAML).

METHODS

We retrospectively analyzed the clinical and pathological data of 93 patients with AML treated with robot-assisted partial nephrectomy (RAPN) at three tertiary care referral centers. Renal masses were classified according to the PADUA, SPARE and R.E.N.A.L. nephrometry scores. Surgical success was defined according to the novel Trifecta Score. Logistic regression models (LRM) were fitted to predict the achievement of novel Trifecta and the risk of high-grade Clavien-Dindo (CD) complication. The receiver operating characteristics (ROC) curve analysis was used to estimate the accuracy of LRMs.

RESULTS

Of 93 patients, 66 (69.9%) were females; median tumor size was 42 (36-48) mm. Novel Trifecta was achieved in 79 patients (84.9%) and postoperative complications classified as CD>2 occurred in 7 (7.5%) patients. At univariate and multivariate LRMs all three nephrometry scores were significantly associated with novel Trifecta achievement. Similar findings were observed for the prediction of CD>2 complications. The AUCs to predict optimal surgical outcomes and CD>2 complications were 0.791 and 0.912 for PADUA, 0.767 and 0.836 for SPARE and 0.756 and 0.842 for RENAL Score, respectively.

CONCLUSIONS

RAPN appears to be a feasible and safe surgical technique for the treatment of RAML. PADUA, SPARE and RENAL scores can be safely adopted to predict surgical outcomes, with the first one showing a higher accuracy.