In total, 957 cases were initially extracted based on procedure codes from the hospital’s surgery database. This study included 564 procedures for 462 patients, of which 373 had one, 77 had two, 11 had three, and one had four resections in the study period. No patients were lost to follow-up at six months, with the mean follow-up at 182 days. The total follow-up was 102.492 days.
General characteristics are described in Table 1. Male gender was prominent (63%), and mean age at surgery was 67 years (SD 10). Local resection alone or combined with RFA was done in 274 (48%) cases. RFA was the only treatment in 34 (6%) of cases.
Overall morbidity (≥ Grade 2) within 30 days of surgery occurred in 260 cases (46%). Figure 1 describes complication grades further, most notably 93 cases (16%) had a complication of Grade 3 or higher. More than half, 304 (54%) cases, had no complications, 157 (28%) had one, 58 (10%) had two, 28 (5%) had three, and 17 (3%) had four or more. All complications were categorised in Table 2. Wound dehiscence occurred in 18 (3%) cases. A complete list of complications, and their categorisation, is shown in Supplemental Table 1.
Risk factors for severe complications
Complications of ≥ Grade 3a were considered severe, and risk factors associated with these are listed in Table 3. Cases were stratified by major resection with ≥ 3 segments, 134 (24%) cases; resection of three or more segments was associated with severe complications.
Severe complication risk factors in the multivariate model were male gender (OR 2.35, 95% CI: 1.37 - 4.04, P = 0.002), surgery duration (OR 1.12 per 30 minutes, 95% CI: 1.01 - 1.24, P = 0.04), and major resection (OR 2.37, 95% CI: 1.41 - 3.98, P = 0.001). Three or more liver resections was nonsignificant (OR 1.83, 95% CI: 0.83 - 4.02, P = 0.1).
Impact on length of hospital stay
Patients without any complications had a mean length of stay of 4.1 days, which increased with complications: 1.4 days (95% CI: 1.3 – 1.5) for Grade 2, 1.7 days (1.5 – 2.0) for Grade 3a, 2.3 days (95% CI: 1.7 – 3.0) for Grade 3b, 2.6 days (95% CI: 1.6 – 4.2) for Grade 4a, and 2.9 days (95% CI: 2.8 – 3.1) for Grade 4b. Only 20% of patients had a length of ≥ 6 days. Complications were associated with increased length of stay (Table 4). Following were associated with increased length of stay in the multivariate model: highest complication grade, infections, biliary and cardiopulmonary complications, liver insufficiency, and ascites. Notably, postoperative bleeding was not significantly associated with length of stay, and occurred in 7 cases (1.6%), of which one was Grade 3b.
Predictor of short-term survival
The study includes a total of 564 cases. Three patients died within three months (mortality rate 0.5%, 95% CI: 0.2-1.6%) and ten patients died within six months (mortality rate 1.6%, 95% CI: 0.8-3.0%). Two deaths may be attributed to surgery: one was caused by thrombosis of the superior mesenteric artery (two days after surgery) and one by biliary leak (120 days after surgery). One died from cardiac decompensation (day 26). Three patients died from chemotherapy infections and multi-organ failure (days 53, 114, and 177). One patient died of sudden cardiac arrest at home (day 115). Cause of death was unknown in the last three cases (days 155, 165, and 183).
Complication Grade 3a or higher were not significantly associated with mortality (Hazard Ratio (HR) 3.46, 95% CI: 0.90 - 13.32, P = 0.07), while neither involved a number of complications (HR 1.33, 95% CI: 0.95 - 1.86, P = 0.1).
Difference in complications between major and minor liver surgery
Comparison of complications between cases requiring major hepatectomy or not were analysed (Supplemental Table 2). In a multivariate model, cases who required major surgery had significantly more and severe complications, and the incidence of liver insufficiency, ascites, wound complications, and other surgical complications were higher.