Liver Resection for Primary Intrahepatic Stones: Focus on Postoperative Infectious Complications
Executive Summary
Primary Intrahepatic Lithiasis (PIL), characterized by gallstones within the intrahepatic biliary tree, presents a significant surgical challenge due to high postoperative morbidity rates. While liver resection remains the definitive treatment for removing stones and atrophic parenchyma while mitigating cholangiocarcinoma risk, infectious complications frequently compromise recovery.
A retrospective analysis of 73 patients treated between 1992 and 2012 reveals an overall morbidity rate of 38.3%, despite 0% mortality. The study identifies preoperative bacterial colonization—specifically linked to previous invasive biliary procedures—as the primary driver of these complications. Key findings include:
Critical Risk Factors: Previous endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC), and preoperative cholangitis are independent predictors of postoperative infection.
Bacteriological Landscape: Enterococcus and Pseudomonas species are the most prevalent isolates, with high rates of multi-drug resistance (up to 43.9%).
Clinical Imperative: Preoperative infection control and aggressive management of early sepsis are essential to improving surgical outcomes.
Overview of Primary Intrahepatic Lithiasis (PIL)
PIL involves the formation of primary gallstones within cystic dilatations of the intrahepatic biliary tree. Historically more prevalent in East Asia, the condition is increasingly reported in Western medical centers.
Clinical Presentation
Patients typically present with a history of:
Biliary pain and jaundice.
Recurrent pyogenic cholangitis.
Acute pancreatitis.
Parenchymal atrophy and biliary strictures.
Surgical Rationale
Liver resection is considered the treatment of choice for localized PIL to:
Completely remove stones and biliary strictures.
Excise atrophic parenchyma.
Reduce the incidence of cholangiocarcinoma (detected unexpectedly in 8.2% of surgical specimens in this study).
Analysis of Surgical Procedures
The choice of surgical procedure is dictated by the location of stones and the presence of strictures or atrophy. Surgery is ideally performed at least one month after the most recent episode of acute cholangitis.
Key Intraoperative Details:
Caudate Lobe Involvement: Involved in 12.3% of cases; caudate lobectomy was performed in 23.6% of left hepatectomies.
Drainage: Biliary external drainage was utilized in 58.9% of patients.
Techniques: Procedures utilized Kelly crushing or Cavitronic Ultrasonic Surgical Aspirator (CUSA) systems, with intraoperative ultrasound and cholangiography used to ensure stone clearance.
Microbiological Profile and Bactibilia
Bacterial colonization of the bile (bactibilia) is a central factor in postoperative outcomes. A total of 133 microorganisms were isolated from bile cultures during the study.
Isolated Microorganisms
Enterococcus species: 44 isolates (43.9% multidrug-resistant).
Pseudomonas species: 29 isolates (41.2% multidrug-resistant).
Escherichia coli: 19 isolates (20.6% multidrug-resistant).
Klebsiella and Candida species: 10 isolates each.
The study noted that patients with bactibilia had significantly higher infectious morbidity rates (78.6%) compared to those without (13.3%). Mixed infections were common, and multidrug-resistant strains are becoming increasingly frequent.
Postoperative Outcomes and Complications
While the study achieved a 0% mortality rate, the morbidity was substantial, primarily consisting of grade I–II complications (26.0%) and grade III–IV major complications (12.3%).
Distribution of Complications
Wound Infection: 24.6% (18 patients).
Bile Leak: 16.4% (12 patients). Notably, every bile leak was associated with fever due to the high prevalence of infected bile.
Bacteremia: 15.1% (11 patients).
Postoperative Cholangitis: 6.8% (5 patients).
Intra-abdominal Abscess: 6.8% (5 patients), requiring percutaneous drainage.
Statistical Risk Factor Analysis
Multivariate analysis identified two primary independent risk factors for postoperative infectious complications.
Critical Observations:
Procedural Impact: 96.4% of patients with positive bile cultures had previously undergone ERCP or PTC, suggesting these diagnostic/therapeutic procedures introduce bacterial contamination.
Disease Duration: 34.2% of patients had symptoms for over five years prior to referral, potentially increasing the window for colonization.
Surgery Duration: Unlike other studies, the duration of surgery (above or below 4 hours) was not found to be a significant risk factor in this series.
Clinical Conclusions and Recommendations
Postoperative morbidity in PIL is strictly related to preoperative biliary infection. To optimize outcomes, the following strategies are emphasized:
Limit Invasive Diagnostics: Use Magnetic Resonance Imaging (MRI) and MRCP to study bile ducts whenever possible to avoid the bacterial contamination associated with ERCP and PTC.
Preoperative Infection Control: Pursue effective control of biliary sepsis before attempting resection. The use of synbiotics or wound protectors may be considered to attenuate inflammatory responses.
Intraoperative Vigilance: Perform routine bile cultures during surgery and thoroughly wash the biliary tree with saline. Intraoperative ultrasound is essential for identifying bile ducts filled with stones that are not visible via cholangiography.
Aggressive Sepsis Management: Maintain a high index of suspicion for early signs of sepsis postoperatively. Because of high multidrug resistance, antibiotic therapy should be guided by repeated cultures and administered promptly.
