Retroperitoneal approach for robot-assisted partial nephrectomy: technique and early outcomes

OBJECTIVES

The aim of our study is to present early outcomes of our series of retroperitoneal-RAPN (Robot Assisted Partial Nephrectomy).

MATERIALS AND METHODS

From September 2010 until December 2015, we performed 81 RAPN procedures (44 at left kidney and 37 at right). Average size was 3cm (1-9). Average PADUA score 7.1 (5-10). Average surgical time (overall and only robot time), ischemia time, blood loss, pathological stage, complications and hospital stay have been recorded.

RESULTS

All of the cases were completed successfully without any operative complication or surgical conversion. Average surgical time was 177 minutes (75-340). Operative time was 145 minutes (80-300), overall blood loss was 142cc (60-310cc). In 30 cases the pedicle was late clamped with an average ischemia time of 4 minutes (2-7). None of the patient had positive surgical margins at definitive histology (49pT1a, 12pT1b, 3pT2a, 2pT3a). Hospital stay was 3 days (2-7).

CONCLUSIONS

The retroperitoneal robotic partial nephrectomy approach is safe and allows treatment of even quite complex tumors. It also combines the already well known advantages guaranteed by the da Vinci® robotic surgical system, with the advantages of the retroperitoneoscopic approach.

[Color-Doppler and angioplasty in renovascular hypertension]

Renovascular hypertension is defined as a kind of hypertension secondary to altered renal perfusion with the activation of the renin-angiotensin system. Since a large number of these patients benefits from treatment--be it medical, surgical or angioplastic--a non-invasive low-cost method allowing accurate screening was looked for. Color-Doppler was employed by many authors to evaluate renovascular hypertension, for both the early diagnosis of the condition and the evaluation of treatment results in renal artery stenoses. However, the authors agree that color-Doppler cannot play a major role in the screening of renovascular hypertension due to the various qualitative and quantitative variables not being adequately codified, to the lack of a single color-Doppler method and to the difficult comparison of the results from the different units. Nevertheless, improved results are promised by technological evolution, together with the possibility to codify color-Doppler variables more easily repeatable. B-mode units with 3.5 and 5 MHz probes were employed in the thinnest subjects. In 5-25% of cases accessory renal arteries were observed. After identifying the vessel to be studied with several spatial scans, the smallest possible sample volume (usually 3-5 mm) was positioned. The normal flowmetric range was 0.07-0.1 s: it must not exceed 0.16 s, with persistence of high diastolic flow. Some authors' criteria were followed to define either stenosis or renal artery obstruction; moreover, pulsatile flow index was considered, together with the resistive index, pulsatility index and stenosis index.

Hypertension in end-stage renal failure: role of sympathetic nervous system, sodium balance and renal pressor system

120 subjects, including 16 normal volunteers, 23 essential hypertensive and 81 uraemic patients (34 before the start of haemodialysis and 47 during maintenance haemodialysis) were studied in order to evaluate the interrelationship between mean arterial pressure (MAP) and total exchangeable sodium (NaE), plasma renin activity (PRA) and plasma catecholamines (PC). Significant positive correlations were noted between MAP and PRA and between MAP and PC in the total group of uraemic patients. In patients under conservative treatment MAP correlated significantly with NaE and PRA. Multiple regression analysis demonstrated that the combined effect of NaE and PRA accounted for 50 per cent of the levels of MAP. In patients undergoing chronic haemodialysis MAP lost any correlation with NaE. In these patients the presence of hypertension seemed to be related to the values of PRA and PC. PC increased after two hours of walking and hypertensive patients had higher increments than normotensive patients. These data might support an important role for the adrenergic system in the maintenance of hypertension in dialysis patients.

Prognostic value of captopril renal scintigraphy in renovascular hypertension

This study evaluates the prognostic value of captopril renal scintigraphy in hypertensive patients undergoing renal artery revascularization. Preoperative studies of 51 patients were correlated with blood pressure results at 6- and 12-mo follow-up. Captopril-renal scintigraphy was carried out 1 hr after oral administration of 50 mg of captopril, using either 220 MBq of 99mTc-DTPA or 74 MBq of 99mTc-MAG3, followed by a baseline study in case of abnormal results. Evidence of amelioration or normalization in relation to captopril study was considered predictive of blood pressure control following treatment. Blood pressure response was favorable in 37 patients, but failed to show any improvement in 14. The scintigraphic test was positive in 33 patients (15 cured, 17 improved, 1 failed) and negative in 18 (3 cured, 2 improved, 13 failed). Sensitivity and specificity for renovascular hypertension was 86.5% and 93%, respectively. For blood pressure cure and improvement, the test had positive and negative predictive values of 97% and 72%, respectively. A positive preoperative captopril renal scintigraphic result is a strong predictor of hypertension curability by renal artery revascularization.