Discussion
The increase in the average human life expectancy and aging population will result in more geriatric patients with kidney stones admitted for treatment. Developments in technology, especially in endoscopy and optic quality, have led to numerous stone treatment modalities in elderly patients.13 PCNL and RIRS have become important management modalities in this area. PCNL is considered to be an effective and safe treatment option for large renal stones.14 Despite proof of the effectiveness of the procedure, complications ranging from 20 - 83% were reported in the literature, including hemorrhage requiring transfusion, pleural injury and colonic injury. Technological innovations have meant that RIRS has become accepted as important treatment modality of renal stones, with higher success and lower complication rates. Previous studies clearly demonstrated that RIRS can be successfully performed for moderate size renal stones.15 In a different study, Gupta and colleagues concluded that PCNL provides better one-time stone-free rates (>90%) compared to other procedures.16Knoll et al. emphasized that one in two patients receiving RIRS required two procedures for a mean stone size of 19 mm.17 This is undesireable because multiple anesthesia exposure is problematic for elderly patients.
Although many studies have investigated outcomes of either RIRS or PCNL in elderly patients, there is lack of comparative studies. To our knowledge, the present study is the first on the effect of CCI on complications and outcomes in elderly patients. Ozgor et al. evaluated a total of 118 elderly patients, 60 of them underwent RIRS and 58, mPCNL, and reported stone-free rates of 81.7% and 77.6%, respectively.18 Akman et al., found similar success rate between PCNL and RIRS in geriatric patients with moderate-size renal stones (92.8% and 82.1%, respectively).15 In contrast, in the present study, the stone free rate was significantly higher in PCNL than RIRS (92% and 77.8%, respectively) (p=0.021). Similar to our results, comparing the effectiveness of RIRS and mPCNL in older patients, Hu found that the success rate was statically significantly in favor of mPCNL (p = 0.025).13 The present study showed no correlation between CCI and success in either group.
In this study, the mean operative time was longer in PCNL group compared with f-URS group, but this difference was not statistically significant.In contrast, many previous studies reported longer operative times in the RIRS group.19-21 In a study involving 56 geriatric patients comparing standard PCNL and RIRS, Akman et al. found that operative duration was longer in favour of f-URS (64.5 ± 20.9 and 40.7 ± 10.7 min).15 Another study by Hu et al. found no significant difference in terms of operative time in older patients following mPCNL and RIRS.13 This variability can be attributed to surgical competence and experience, positioning and patient-dependent factors during operation. There are mixed results on the correlation between operative times and CCI. A study conducted by Resorlu et al.22 reported that CCI was not a predictive factor for operative duration of PCNL in elderly patients, however, Unsal et al.23 noted a positive correlation. In our study, we found that CCI was not a predictor on operative times for either PCNL or RIRS group.
Previous reports emphasized that PCNL has a longer hospitalization times compared to RIRS.13,15,18 In contrast to the high morbidity of PCNL, for patients undergoing RIRS, there are lower rates of pain, hemoglobin drop, and requirement for blood transfusion requirement, and the absence of nephrostomy tubes seem to accelerate postoperative recovery, accounting for the reduced hospital stay.The effect of age and patients’ comorbidities on hospitalization stay is a controversial issue. Okeke et al. stated that, after PCNL, hospitalization time was longer in older compared to younger patients.24 In contrast, studies conducted by Karami et al. and Sahin et al. report no significant difference between older and younger patients undergoing PCNL in terms of hospitalization time.25,26 Ozgor et al. found a significantly longer hospitalization time following mPCNL (56.5 hours) compared to RIRS (23.1 hours) in elderly patients (p < 0.001).18 In accordance with the literature, our study revealed PCNL was associated with longer hospitalization stay in older patients. Unsal et al.22 and Resorlu et al.23 found CCI has no effect on hospitalization times after PCNL, but the present study reported a significant positive correlation in both PCNL and RIRS.
Elderly patients are more prone to comorbid disease, making them more vulnerable to bleeding and septic complications.15Such complications can be fatal. The use of minimally invasive surgical techniques to achieve complete stone clearance with minimal morbidity is an important advance in the management of nephrolithiasis in older patients. de la Rosette et al. and Tefekli et al. reported that overall complication rates in PCNL were 43.8% and 29.2%, respectively.27,28 In the present study, the overall complication rate (32.6%) was in accordance with other series on PCNL, but it was slightly higher than these afor ementioned studies. This can be explained the ages of the patients, a position supported by Okeke’s series, which resulted in significantly higher complication rates in elderly patients compared with younger patients in PCNL.24 Previous reports emphasized similar and acceptable complication rates for both PCNL and RIRS. Akman et al. reported no difference in complication rates in elderly patients following PCNL and RIRS.15 In studies, conducted by Ozgor et al. and Hu et al., no significant difference in terms of complication rates was detected between older patients undergoing mPCNL and those undergoing RIRS.13,18 However, in present study, overall complication rates were significantly higher in PCNL group (p=0.034), and here, the Clavien-Dindo grade >2 complications were mainly observed in PCNL group (p=0.043). Another study by Unsal et al. evaluated the efficacy of CCI on PCNL to predict of morbidity and mortality, and found the CCI to be a predictive factor.23 Aykac et al. observed that a CCI score of 2.5 was the cut-off value for medical complications of RIRS in geriatric patients.29 In the current study, overall complication and major complications rates were significantly higher in CCI score ≥2 patients who underwent PCNL. Furthermore, there was significant positive correlation between CCI and complication rates in both PCNL and RIRS.
The first is its retrospective design with small number of patients, which is a possible cause of bias. Second, we used CCI, an index designed to predict mortality using 19 comorbid conditions, to predict surgical complications only, and not medical complications. Another limitation is short patient follow up, with no long-term comparison of complications. There is a need for prospective studies in geriatric patients with a larger series, focusing on medical complications.