Laparoscopic cholecystectomy was performed using a standard 4-port technique. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) was utilized in patients with common bile duct stones. Routine intraoperative cholangiography was not performed.

The following patient data were recorded: age, sex, American Society of Anesthesiologists (ASA) classification, indication for surgery, preoperative ERCP, conversion to open surgery, postoperative length of hospital stay, morbidity, and mortality. Also, as a part of our routine protocol, an arterial blood gas sampling was made in all patients with an operative length of more than 1 hour.

ASA score assessment of the groups revealed that these scores increased with age. The percentage of patients with ASA scores ≥3 was 15.9% in the group of patients 69 years or younger, and increased to 39.4% in the 70 to 74 age group, 66.7% in the 75 to 79 age group, and 81.8% in the group above 80. The differences between the ASA scores were statistically significant (P<0.001) (Table 1).

Arterial blood samples were taken from patients whose operations lasted longer than one hour, corresponding to 26 patients in groups A1, A2, A3 (patients 70 years or older) and 152 patients in group B (patients 69 years or younger). The PaCo₂ and pH values in these samples were compared. Mean PaCO₂ was found to be 34.13±8.36mm Hg in the 70 to 74 age group (Group A1), 39.37±4.92mm Hg in the 75 to 79 age group (group A2), 38.01±10.2mm Hg in patients 80 years or older (group A3). Mean pH values in groups A1, A2, and A3 were 7.419±0.062, 7.393±0.068, and 7.433±0.076, respectively. In group B, mean PaCO₂ was 39.22±10.05mm Hg and mean pH was 7.385±0.087. The differences between the groups with respect to mean PaCO₂ and pH measurements were not significant (P>0.05).

The majority of the patients in all study groups who were operated on had a diagnosis of chronic cholecystitis. Patients operated on for acute cholecysititis constituted 16.2% and 14.8% of all patients in groups A and B, respectively. This difference with respect to acute cholecystitis was not statistically significant between the 2 groups (P=0.765). However, subgroup analysis of patients ≥70 revealed that the rate of acute cholecystitis was 45.5% in patients aged ≥80, which was significantly higher (P=0.029)

Patients in all groups with clinical or biochemical suspicion of choledocolithiasis were further evaluated with ultrasonography or magnetic resonance cholangiopancreatography (MRCP), and among these patients 14 who were diagnosed with bile duct stones underwent preoperative sphincterotomy with ECRP and stone extraction.

Conversion to open cholecystectomy was required in 10 of the 68 (14.7%) patients in the group of patients ≥70, and 42 of the 527 patients (8%) in the group ≤69. Although the conversion rate was higher in the older age group, the difference was not statistically significant (P=0.765). Subgroup evaluation in group A revealed that conversion rates were 12.1%, 12.5%, and 27.2% in patients aged between 70 and 74, between 75 and 79, and 80 and above, respectively. The conversion rate in patients aged 80 or above was significantly higher than that in the other groups (P>0.05). In all age groups, the most common reason for conversion was failure to adequately visualize the biliary tract anatomy due to intense fibrosis around the gallbladder and Calot's triangle. Other reasons for conversion to open surgery in this study were intraoperative bleeding uncontollable by laparoscopy, dense adhesions due to prior laparotomy that prevented a laparoscopic approach, injury to the main bile duct, and suspected gallbladder cancer. The indications for conversion according to age groups are given in Table 2.

Postoperative complication rates were 9.7% in patients ≤69 and 13.2% in patients ≥70; however, this difference was not statistically significant (P=0.359). Subgroup analysis in group A revealed that patients aged 80 or older (group A3) had a 36.4% complication rate, which was significantly higher than that in all other groups (P=0.027). The distribution of the complications according to age groups is given in Table 3. Mean hospitalization was 1.53±1.21 days in the group A and 2.50±1.84 in group B, which was statistically significant (P<0.01). Subgroup analysis in group A revealed that the length of hospital stay increased as age increased. No deaths occurred in either group.

In laparoscopic cholecystectomy, carbon dioxide pneumoperitoneum has potentially harmful intraoperative circulatory and ventilatory effects because of absorbed carbon dioxide and elevated intraabdominal pressure. Although not clinically significant for healthy patients, these effects are assumed to be deleterious for patients with a high risk for anesthesia (ASA 3 and 4).^8,9 Therefore, all patients with an operative period >1 hour (26 patients in groups A1, A2, and A3 and 152 patients in group B) had assessment of PaCO₂ and pH values in blood samples drawn at the end of the first hour of the operation. The difference between the groups was not statistically different (P>0.05). These results were consistent with the findings of Koivusola et al¹⁰ who reported that during laparoscopic cholecystectomy the pneumoperitoneum induced with 10mm Hg to 12 mm Hg pressure in patients with ASA scores 3 or 4 did not pose additional risks in elderly patients.

Previous studies have shown that the incidence of acute cholecystitits is higher in elderly patients.^5,11 In our study, although the acute cholescystitis was more frequent in patients aged 70 or older compared with younger individuals, this difference was not statistically significant. On the other hand, subgroup analysis of patients older than 70 revealed that the rate of acute cholecystitis was 45.5% in patients aged 80 or older, and this was significantly higher than that in the other groups (P=0.029). We believe this finding explains the higher complication rates in patients above age 80 reported in the literature.^12,13

Conversion to open surgery was 14.7% in the elderly group. This figure is concordant with the numbers reported in the literature, which range between 5% and 25%.^5,14,15 The conversion rate was 8% in the younger age group. Although the conversion rates were higher in the elderly group of patients >70, this did not reach statistical significance (P=0.765). However, subgroup analysis of group A (70 or older) revealed that patients aged 80 or older had a significantly higher conversion rate than that in other subgroups (P<0.01), a finding which is also in agreement with the literature. Increased age has been noted in the literature as a preoperative risk factor for conversion, perhaps due to a longer history of gallstones and increased number of cholecystitis attacks.^16,17

The most important advantage of laparoscopic cholecystectomy in elderly patients is the associated reduction in morbidity and mortality rates. The reported incidence of morbidity and mortality with open cholecystectomy in the geriatric population is approximately 23% to 28% and 1.5% to 2% respectively.^18,19 In the elderly who underwent laparoscopic cholecystectomy, complication rates of 5% to 15% and an overall mortality rate of 0% to 1% have been observed.^2,11,20 There was no mortality in our study. Although the complication rates were slightly higher in the group aged 70 or older compared with the younger group of patients (13.2% vs 9.7%, P=0.359), these figures are still lower than the reported complication rates for open cholecystectomy. Subgroup analysis of elderly patients showed that complication rates increase significantly in the group aged 80 or older. Another important point is the lack of pneumoperitoneum-dependent complications in the perioperative period. Higher complication rates observed in patients aged 80 or older seem to be resulting from more difficult cholecystectomies (acute cholecystitis, fibrotic gallbladder, mirizzi syndrome, and others). Therefore, we believe that patients aged 80 or older should preferentially be operated on by experienced surgical staff with good technical equipment, which will help to decrease complication rates.

To identify bile duct stones before laparoscopic cholecystectomy, we routinely evaluate the patients clinically and with ultrasonography. In case the patient has clinical, biochemical, or radiological findings suspicious of the presence of bile duct stones, we perform MRCP (Magnetic Resonance Cholangiopancreaticography), which is a noninvasive and rather sensitive method. Using our algorithm, only 0.7% (4/595) of the stones were missed in our study, all of which could be removed with ERCP after the operation, which may be due to the high sensitivity of MRCP. In the study of Charfare et al²¹ preoperative ERCP was performed, and postoperatively retained stones were present in 1.2% of these patients, similar to our rate. In another study by Collins et al,²² among 997 laparoscopic cholecyctectomy patients, clinically silent choledocholithiasis was present in 3.4%, one-third of which passed spontaneously within 6 weeks of the operation. Based on these previous findings and the results of Nugent et al,²³ we believe that selective biliary imaging like MRCP not only represents a safe and effective tool for preoperative identification of bile stones, but also reduces the need for unnecessary ERCP and intraoperative cholangiography procedures.

Additional support for the benefit of the laparoscopic approach is demonstrated in the decreased length of stay in the hospital. In this study, although the length of hospitalization was shorter in all groups compared with that in open cholecystectomy, it was significantly longer in the elderly group compared with that in the younger patients. These results made us believe that elderly patients also benefited from the shorter hospital stay offered by the laparoscopic technique; however, due to higher complication rates and more frequent conversion to the open technique, they required longer hospitalization periods compared with younger patients.