Partial nephrectomy is an appropriate operation for the treatment of renal masses. In the past, OPN was the standard technique. LPN was later developed and is now increasing in use. In Ramathibodi Hospital, RAPN was first performed in 2015. According to the 2017 American Urological Association guideline [8] and the 12th edition of Campbell Walsh Wein Urology [2], partial nephrectomy is recommended for patients with a cT1a renal mass, solitary kidney, bilateral renal tumors, familial RCC, and CKD or proteinuria as well as young patients with multifocal masses or comorbidities that may impact renal function in the future. The most common complications after partial nephrectomy are urine leakage, postoperative bleeding, urinary tract infection, arteriovenous malformations, pseudoaneurysms, and renal abscesses [11].
In the present study, the three groups had similar baseline patient and tumor characteristics except for the RENAL nephrometry score, which was highest in the RAPN group (p = 0.005). The EBL was highest in the OPN group (OPN > RAPN > LPN, p = 0.041). The percentage of patients who required perioperative PRC transfusion (OPN > LPN > RAPN, p = 0.015) and postoperative PRC transfusion (p = 0.037) was lowest in the RAPN group. The operative time was longest in the RAPN group (RAPN > LPN > OPN, p < 0.001). LOS was not different among the three groups. The rate of positive surgical margins was not significantly different among the three groups but was highest in the LPN group. The rate of collecting system penetration was lowest in the RAPN group. No injury to major vessels or other abdominal organs occurred in any group.
Six patients required conversion to radical nephrectomy. One patient who underwent OPN was converted to open radical nephrectomy because of massive bleeding (EBL of 4300 mL) after unclamping of the renal artery (RENAL score of 8A). The other five patients who underwent RAPN were converted to robotic-assisted radical nephrectomy because of high mass complexity in four patients (RENAL scores of 10P, 10P, 11A, and 10P) and mass involvement of the renal hilum in one patient (RENAL score of 6P).
Two patients underwent conversion to open surgery (LPN to OPN) because of massive adhesion and no progression of LPN in one patient and massive bleeding (EBL of 1500 mL) after unclamping of the renal artery in the other patient.
Three patients developed severe postoperative complications after OPN. The first patient had a grade 3a postoperative arteriovenous fistula (AVF) s/p angiogram requiring embolization. The second patient had grade 4 postoperative respiratory failure requiring mechanical ventilation. The third patient had grade 4b postoperative cardiac arrest with atrial fibrillation requiring rapid ventricular response, respiratory failure with hospital-acquired pneumonia requiring mechanical ventilation, and acute kidney injury requiring hemodialysis.
Three patients developed severe postoperative complications after RAPN. The first patient had a grade 3a postoperative AVF s/p angiogram requiring embolization. The second patient had grade 4a postoperative end-stage renal disease requiring long-term hemodialysis. The third patient had grade 4b postoperative respiratory failure requiring mechanical ventilation and end-stage renal disease requiring long-term renal replacement therapy.
The number of patients with ≥ 90% preservation of the eGFR at the 1-year follow-up was not significantly different among the three groups. The proportion of patients (n = 116) who achieved the trifecta outcome was also similar among the groups (p = 0.736). In the multivariate analysis, the factors that affected the trifecta outcome were the LOS and rate of intraoperative complications.
Three patients were readmitted. One patient was given intravenous antibiotics to treat an infected intra-abdominal collection after RAPN, one underwent angiography and embolization of a renal AVF after RAPN, and one underwent angiography and embolization of a renal AVF after OPN.
As in our study, Mehra et al. [16] found that blood loss was lowest in the RAPN group (OPN > LPN > RAPN, p = 0.042). This can be explained by better visualization of the anatomy and movement control of instruments in RAPN. Similarly, Khalifeh et al. [17] concluded that the rate of a positive surgical margin was lower in RAPN than LPN. This may be due to technical difficulty when performing LPN, especially when the mass is in the upper pole or a posterior location.
Both Zargar et al. [18] and Xia et al. [19] reported that the rate of intraoperative complications was similar in OPN and RAPN. According to Khalifeh et al. [17] and Porpiglia et al. [13], the rate of postoperative complications was lower in RAPN than in LPN and OPN.
As in our study, Zargar et al. [20] found that the postoperative creatinine concentration and eGFR were not different between LPN and RAPN. Yerram et al. [15] found that the proportion of patients with ≥ 90% eGFR preservation at follow-up was not different between OPN and RAPN.
As in our study, Yerram et al. [15] found that achievement of the trifecta outcome (defined as negative surgical margins, no urologic complications, and ≥ 90% eGFR preservation at last follow-up) was not different between OPN and RAPN. This may be explained by the fact that LPN is inferior to both surgical OPN and RAPN because of its more challenging surgical techniques.
Zargar et al. [20] compared 646 LPN with 1185 RAPN procedures and defined the trifecta outcome as negative surgical margins, no perioperative complications, and a warm ischemia time of ≤ 25 min. They found that the factors predicting achievement of the trifecta outcome were the type of surgery (RAPN), tumor size, EBL, and operative time.
As in our study, Mehra et al. [16] found that the operative time was not different among the three groups. In contrast, however, Khalifeh et al. [17] found that the operative time was shorter for RAPN than LPN. This can be explained by the steep learning curve of RAPN and the greater complexity of renal masses (higher RENAL scores) in the RAPN group in our study.
In contrast to our study, Han et al. [21] and Kim et al. [22] concluded that the LOS was significantly shorter for RAPN than OPN. LOS can be affected by many factors, including patient pain control, patient preference, socioeconomic status, and our institute practice.
Khalifeh et al. [17] and Porpiglia et al. [13] concluded that the rate of postoperative complications was lower in RAPN than LPN and OPN. However, we found no statistically significant difference in postoperative complications among our three groups.
Our study has three main limitations. First, it was a retrospective study with a small sample size. Second, the surgeries were performed by eight surgeons, which may have resulted in different outcomes. Third, performance of the eGFR evaluation at 1 year may have been too early to determine the actual long-term renal function outcomes.