Discussion:
The increase in the average life expectancy and aging population has resulted in more renal stones being detected in geriatric patients. It is important to determine the most appropriate method when treating renal stones in elderly patients due to age-related cardiovascular and pulmonary system deterioration and presence of multiple comorbidities. In elderly patients with multiple comorbidities, observation may be an option for asymptomatic small stones. However, in elderly patients, stone growth is observed to occur over a shorter time, and urinary tract infection causes pain that requires obstruction and analgesics (10), adversely affecting their kidney functions. Although PCNL is accepted as an effective and safe method in large renal stones, it can result in major complications. Skolarikos and de la Rosette reported that the rate of major complications after PCNL was 0.9-4.7% for septicemia, 0.6-1.4% for renal bleeding requiring an intervention, 2.3-3.1% for pleural injury, and 0.2-0.8% for colonic injury (11). Changes in the cardiorespiratory reserve of elderly patients make them less tolerant to bleeding or septic complications (12). Therefore, a detailed evaluation and a careful approach are required in the treatment of renal stones in elderly patients.
Despite advances in instrumentation and technology, staghorn stones are difficult to manage. In a study retrospectively reviewing 42 PCNL procedures performed on 33 patients aged 65 years and older compared with younger patients (47% of the stones were staghorn), 82% (27/33) of the patients were determined to achieve stone-free status or have fragments smaller than 5 mm at three months after surgery. In this study, PCNL was shown to be a safe and effective treatment for elderly patients, even in the presence of complex renal stones; however, a higher rate of transfusion was required in this group (13). Şahin et al. reported the PCNL results of 27 patients aged over 60 years and compared them to 178 PCNL procedures performed in 166 younger patients at the same time interval (14). Only 25% of the patients had staghorn renal stones, and the success rate (stone-free status or fragments smaller than 4 mm) was 89% for the elderly and 92% for the younger patients. In contrast to previous studies reporting higher stone-free rates (78-93%) after PCNL in staghorn renal stones (5,15), the success rates obtained from the current study including only complete staghorn stones were found to be 67.4% and 54.7%, for the elderly and younger groups, respectively. This lower rate of success can be explained by technical limitations, such as the exclusion of partial staghorn stones, use of only one access point for each patient, lithotripsy being performed only with a pneumatic lithotripter, and not using a flexible nephroscope. Similar to our study, Kuzgunbay et al., who performed 47 PCNL procedures in 45 patients aged 65 years with complete staghorn stones and compared their data to 37 younger patients, found the success rate after the first procedure as 53% in the elderly group and 37.8% in the control group (16).
In our study, in which only complete staghorn stones were included, there was no significant difference between the stone sizes of the elderly and younger patients, which shows the comparability of the two groups in terms of stone burden. Furthermore, length of hospital stay, operation and fluoroscopy durations, and success rate were found to be similar in the elderly and younger groups. Therefore, we consider that advanced age does not have a negative effect on intraoperative parameters and postoperative outcomes in complex stones. However, in our study, while the decrease in hemoglobin was significantly higher in younger people (1.9 ± 1.3 g/dl versus 1.3 ± 1.2 g/dl, p = 0.001), the rate of transfusion requirement was moderately higher in the elderly (7.2% versus 18.6 %). This suggests that the rate of transfusion was higher in the elderly relative to the decrease in hemoglobin. The higher transfusion rate in the elderly indicates that they have lower tolerance to hemoglobin drop. Stoller et al. found higher blood transfusion rates after PCNL in elderly patients with complex renal stones (13). Şahin et al. reported the transfusion rates after PCNL as 21% in elderly patients and 18% in younger patients (14). In another study, the transfusion rate after PCNL in staghorn renal stones was detected as 10.6% in the elderly and 13.5% in the younger group, while the hemoglobin change was 1.46 ± 1.29 g/dl and 1.70 ± 1.33 g/dl, respectively (16).
Percutaneous nephrolithotomy is recognized as an effective and safe treatment option for large renal stones. Although the efficacy of the procedure has been proven, complication rates of up to 83% have been reported in the literature, including bleeding requiring transfusion (7%), organ damage (0.4%), and infectious events (up to 33%) (17,18). Elderly patients tend to have more comorbidities, making them more vulnerable to fatal bleeding and septic complications (19). In a study by Okeke et al., the overall complication rate after PCNL was significantly higher in elderly patients compared to younger patients (20). However, Karami et al. reported that age alone was not a predictive factor for high complication rates (21). In another study, no major complications were observed after PCNL in staghorn renal stones in the elderly and younger population, and their minor complication rates were similar (16). In contrast, in our study, there was a higher rate of minor complications, such as bleeding requiring transfusion in eight and postoperative fever requiring antibiotic change in seven of the 43 patients in the elderly group, while sepsis, pneumothorax and bowel injury were not observed in either group. This suggests that elderly patients are less tolerant of bleeding and less resistant to infectious events because they are more prone to having comorbidities. To our knowledge, this is the first study to separately evaluate post-PCNL complications in elderly patients with staghorn renal stones according to the Clavien-Dindo classification.
There are some limitations to our study. First, it had a retrospective design and a limited number of patients. Second, there was no long-term comparison of surgical complications. Finally, there is a need for prospective studies with a larger series of geriatric patients with staghorn stones, focusing specifically on complications, as well as evaluating their medical complications.