A Prospective Observational Comparative Study of Percutaneous Catheter Drainage and Percutaneous Needle Aspiration in Treatment of Liver Abscess

INTRODUCTION

Liver abscesses remain a significant public health issue, particularly in developing countries, due to their morbidity and mortality burden. It is defined as a localized pus collection within the liver parenchyma, commonly caused by Entamoeba histolytica (amoebic) and Klebsiella pneumoniae (pyogenic).^[1] The condition often results from biliary tract infections, hematogenous spread, or adjacent organ extension. Risk factors include diabetes, chronic alcoholism, immunosuppression, and poor sanitation.^[2]

Diagnosis is based on clinical symptoms fever, abdominal pain, weight loss), laboratory findings (leukocytosis, altered liver function), and imaging (USG, CT).^[3] Previously managed via open surgery, liver abscesses are now primarily treated with minimally invasive methods— percutaneous needle aspiration (PNA) and percutaneous catheter drainage (PCD).^[4] PNA, involving fine-needle aspiration under imaging guidance, is cost-effective and suited for smaller abscesses but may need repeat sessions.^[5] PCD involves catheter insertion for continuous drainage and is preferred for large or multiloculated abscesses; however, it may incur higher costs and complications, such as catheter blockage.^[6] The choice between PNA and PCD depends on the characteristics of the abscess and patient factors, with both showing high success rates; however, comparative efficacy remains debated.^[7] While several studies have assessed liver abscess management, variation in reported outcomes necessitates further research ^[8]

A thorough understanding of patient profiles, including age, comorbidities, and abscess features, is vital for optimizingcare.^[9,10]

This study compares ultrasound-guided PNA and PCD, aiming to inform evidence-based treatment strategies.

MATERIAL AND METHODS

This prospective observational analytical study was conducted in the Department of General Surgery at People’s Hospital, Bhopal, with the aim of comparing the effectiveness of ultrasound-guided percutaneous needle aspiration (PNA) and percutaneous catheter drainage (PCD) in the treatment of liver abscesses. The study was carried out from May 1, 2023, to October 30, 2024, with data analysis and manuscript preparation extending from November 1, 2024, to March 31, 2025. A total of 75 cases were included using purposive sampling, based on consecutive hospital presentations during the study period.

Inclusion criteria were patients with liver abscess confirmed by clinical signs, symptoms, and ultrasound findings, with abscess size ≥5 cm or volume >100 cc. Patients with comorbidities were included and categorized separately. Exclusion criteria included ruptured abscesses before intervention, previous aspiration or drainage, and those with coagulopathy or associated malignancy. Patients were divided into two groups: Group A underwent percutaneous needle aspiration using an 18-G trocar needle, and Group B underwent percutaneous catheter drainage with a 12F–16F pigtail catheter using the trocar technique. All procedures were performed under sterile conditions and ultrasound guidance.

Clinical, laboratory, and radiological parameters were assessed, including symptoms such as fever, abdominal pain, and vomiting; laboratory investigations, including complete blood count (CBC), liver function test (LFT), kidney function test (KFT), and coagulation profile; and radiological findings, including abscess size, cavity volume, and resolution. Data were collected through structured proformas covering pre-, intra-, and post-procedure details, with follow-ups at discharge, 7 days, and 15 days post-intervention. Outcome measures included hospital stay duration, clinical improvement, abscess reduction, and complications.

Data were analyzed using Statistical package for the social science (SPSS) version 25.0. Descriptive statistics were used for baseline characteristics, and inferential statistics, including t-tests and chi-square tests, were used to compare outcomes between the groups. A p-value < 0.05 was considered statistically significant. Ethical clearance was obtained from the institutional review board, and written informed consent was taken from all participants in their local language. Patient confidentiality was strictly maintained throughout the study.

RESULTS

The [Table 1] indicated that the mean age of the patients was 39.71±10.15 years. The median age was 37 years, and the most frequently occurring age was 32 years. The minimum age recorded was 20 years, while the maximum was 66 years.

Out of 75 liver abscess cases, the highest incidence was in the 31–40-year age group (43 cases, 57.3%), followed by the 41– 50-year and 51–60-year age groups (11 cases each, 14.7%). The condition was more common in males (69 cases, 92%) compared to females (6 cases, 8%). Occupation-wise, farmers constituted the largest group (37 cases, 49.3%), followed by office workers (14 cases, 18.7%), laborers (10 cases, 13.3%), and others. The distribution was nearly equal between rural (37 cases, 49.3%) and urban (38 cases, 50.7%) residents.

Abdominal pain was a universal symptom, present in all cases (100%), followed by fever in most cases (86.7%) [Table 2]. Other common symptoms included loss of appetite (48%), nausea/vomiting (42.7%), and cough (33.3%). Diarrhea (21.3%) and icterus (4%) were less frequently observed. On physical examination, right hypochondrial tenderness was present in the majority (93.3%), and localized guarding was seen in 42.7% of cases. Hepatomegaly was found in 30.7%. A notable risk factor was alcoholism, reported in 84% of the cases, suggesting a strong association with liver abscess occurrence.

Most cases (73.3%) had hypoalbuminemia (≤3.4 g/dL), and a striking 92% had elevated serum ALP (>150 IU/L), indicating significant hepatic involvement [Table 3]. Hyperbilirubinemia (greater than 1.2 mg/dL) was observed in 16%, while elevated AST and ALT levels were noted in 21.3% and 17.3%, respectively. Elevated prothrombin time (>13.5 s) was reported in 26.7% of cases. Leukocytosis was common, with 52% having WBC counts >15,000/µL. Solitary abscesses were predominant (89.3%), and most abscesses measured between 101 and 250 cc (70.7%). Microbiological cultures showed no growth in 80% of cases; among positive cultures, E. coli (6.7%) and K. pneumoniae (5.3%) were the most frequent isolates.

In this study of 75 liver abscess cases, 27 were treated with percutaneous needle aspiration (PNA) and 48 with percutaneous catheter drainage (PCD) [Table 4]. The gender distribution was comparable between the two groups, with males comprising 92.6% in the PNA group and 91.7% in the PCD group. The mean age was similar: 39.81 ± 12.39 years in the PNA group and 39.65 ± 8.78 years in the PCD group. The mean size of the abscess was significantly smaller in the PNA group (124.26 ± 14.31 cc) compared to the PCD group (288.10 ± 117.06 cc), highlighting that PCD was preferred in larger abscesses. Clinical improvement was achieved slightly faster in the PCD group, with a mean duration of 10.63 ± 1.95 days versus 11.44 ± 4.46 days in the PNA group. Similarly, the mean time for a reduction in abscess cavity size by more than 50% was shorter in the PCD group (12.46 ± 2.03 days) than in the PNA group (14.37 ± 4.68 days). However, the mean hospital stay was nearly identical between the two groups—16.33 ± 4.73 days in the PNA group and 16.21 ± 1.61 days in the PCD group [Table 4].

Regarding procedural success, all 48 cases in the PCD group (100%) were managed with a single intervention, while 7 cases (25.9%) in the PNA group required a second aspiration. Pleural effusion was observed in 2 cases (7.4%) in the PNA group and 6 cases (12.5%) in the PCD group. In terms of outcomes, complete resolution of the abscess was seen in 88.9% (24/27) of the PNA group and 95.8% (46/48) of the PCD group, while partial resolution occurred in 11.1% and 4.2% of the cases, respectively.

DISCUSSION

Liver abscess continues to pose a clinical challenge, particularly in developing regions where amoebic and pyogenic etiologies are common. Minimally invasive techniques like Percutaneous Catheter Drainage (PCD) and Percutaneous Needle Aspiration (PNA) have become preferred due to their lower morbidity. This study aimed to compare outcomes between these two modalities. The mean age was 39.71 ± 10.15 years, with 57.3% of cases in the 31–40 years group. These findings align with Kumar R.V. et al. (2021),^[9] who reported a mean age of 40.57 ± 9.18 years with a similar peak age distribution. Similar trends were observed in studies by Nigam B. et al. (2019),^[7] Kumar M. et al. (2023),^[11] and Ahmed M. et al. (2020).^[12] A strong male predominance was noted (92%), consistent with Kumar R.V. et al. (92.67%),^[9] Nigam B. et al. (10:1 ratio),^[7] and Ahmed M. et al. (8:1).^[12] Most cases were farmers (49.3%), suggesting occupational exposure risks. Residence was nearly equally distributed (urban 50.7%, rural 49.3%). In contrast, Kumar M. et al. (2023),^[11] reported a 90% rural majority. Abdominal pain (100%) and fever (86.7%) were the most common symptoms, consistent with Kumar R.V. et al.^[9] Kumar M. et al.^[11] and Ahmed M. et al.^[12] Other symptoms included anorexia (48%), vomiting (42.7%), and cough (33.3%). Icterus was the least common (4%). Right hypochondrial tenderness was present in 93.3%, and hepatomegaly in 30.7%, aligning with Kumar R.V. et al.^[9] and Nigam B. et al.^[7]Alcoholism was reported in 84% of cases, similar to Kumar R.V. et al.^[9] (84.67%) and Kumar M. et al.^[11] (74.28%). Hypoalbuminemia was seen in 73.3%, raised S.ALP in 92%, hyperbilirubinemia in 16%, elevated AST in 21.3%, ALT in 17.3%, prolonged PT in 26.7%, and leukocytosis in all cases. These trends match findings by Kumar R.V. et al.^[9] Nigam B. et al.^[7] and Ahmed M. et al.^[12] Pus cultures were sterile in 80%, with E. coli (6.7%) and Klebsiella (5.3%) as the most common isolates. Similar results were seen in Kumar R.V. et al.^[9] Nigam B. et al.^[7] and Ahmed M. et al.^[12] The most frequent abscess size was 101–150 cc (36%), with the mean size significantly larger in the PCD group (288.10 ± 117.06 cc) compared to the PNA group (124.26 ± 14.31 cc), consistent with Kumar M. et al.^[11] All PCD cases (100%) were drained in a single attempt, while 25.9% of PNA cases required two sessions. Similar patterns were reported by Kumar R.V. et al.^[9] and Nigam B. et al.^[7] Mean time to clinical improvement was slightly shorter in PCD (10.63 ± 1.95 days) compared to PNA (11.44 ± 4.46 days), supporting faster recovery with PCD as shown in studies by Nigam B. et al.^[7] Kumar M. et al.^[11] and Ahmed M. et al.^[12] Hospital stay was nearly identical between groups (PNA: 16.33 ± 4.73 days, PCD: 16.21 ± 1.61 days). However, previous studies showed shorter stays with PCD (Kumar R.V. et al.^[9], Ahmed M. et al.^[12]). Time to reduce the abscess cavity by <50% was shorter in PCD (12.46 ± 2.03 days) versus PNA (14.37 ± 4.68 days), consistent with earlier studies. Complete resolution was higher in the PCD group (95.8%) compared to PNA (88.9%), aligning with Kumar R.V. et al.^[9] (PCD: 98.67%, PNA: 84%), Nigam B. et al.^[7] (PCD: 100%, PNA: 76%, p = 0.006), and Ahmed et al.^[12] (PCD: 96.2%, PNA: 89.3%, p = 0.002), supporting PCD as a more effective approach, particularly for larger or more complex abscesses.

CONCLUSION

This study compared Percutaneous Needle Aspiration (PNA) and Percutaneous Catheter Drainage (PCD) in treating liver abscesses. Both methods were effective, but PCD showed better outcomes in terms of clinical improvement (10.63 ± 1.95 vs. 11.44 ± 4.46 days), faster cavity reduction (12.46 ± 2.03 vs. 14.37 ± 4.68 days), and a higher complete resolution rate (95.8% vs. 88.9%). PCD also required fewer procedures. Thus, PCD is preferable, especially for larger or complex abscesses, while PNA remains useful for smaller abscesses.