Feasibility analysis of ultrasound-guided percutaneous catheter drainage for pyogenic liver abscess in non-liquefied stages

Abstract

This letter systematically evaluated a retrospective comparative study by Qiu et al investigating ultrasound-guided percutaneous catheter drainage (PCD) for pyogenic liver abscess management during the non-liquefaction phase. The results demonstrated that early ultrasound-guided PCD significantly shortened hospitalization duration, accelerated fever resolution, and promoted > 50% abscess volume reduction compared to delayed intervention after liquefaction, without increasing procedural risks. While challenging the conventional “wait-for-liquefaction” paradigm, the evidence quality limitations warrant caution, highlighting the need for multicenter prospective randomized controlled trials. Current clinical practice recommends early PCD for severe manifestations (persistent fever, leukocytosis) or immunocompromised patients (including those with diabetes), while prioritizing antibiotic therapy for small abscesses (diameter < 3 cm) or mild cases. Dynamic imaging reassessment and multidisciplinary collaboration remain essential for individualized management. This study provides critical evidence supporting the paradigm shift from empirical observation to precision intervention in pyogenic liver abscess management, though risk-benefit evaluation should precede widespread clinical adoption.

Key Words: Percutaneous catheter drainage; Pyogenic liver abscess; Ultrasonic guidance; Non-liquefied stage; Early intervention

Core Tip: This article evaluated a retrospective study by Qiu et al, which demonstrated that ultrasound-guided percutaneous catheter drainage for non-liquefied pyogenic liver abscesses reduced hospitalization duration, accelerated fever resolution, and promoted abscess volume reduction compared to traditional “wait-for-liquefaction” management, with no increased procedural risks. Current clinical practice recommends early percutaneous catheter drainage for patients with severe symptoms or compromised immunity, whereas antibiotic therapy remains the primary approach for small abscesses or mild cases. Dynamic imaging reassessment and multidisciplinary collaboration are critical for individualized management. Large-scale multicenter prospective randomized controlled trials are still required to validate the efficacy of this precision-driven paradigm shift in pyogenic liver abscess treatment.

TO THE EDITOR

Pyogenic liver abscess (PLA), as a severe infectious disease of the hepatobiliary system, has long been managed through the traditional therapeutic paradigm of awaiting liquefaction prior to intervention. However, recent clinical implementation of ultrasound-guided percutaneous catheter drainage (PCD) has challenged this established approach. A retrospective comparative analysis of clinical data between non-liquefied (59 cases) and liquefied groups (84 cases) demonstrated that early ultrasound-guided PCD significantly reduced hospitalization duration, fever resolution time, and accelerated abscess volume reduction compared with conventional therapeutic approaches, without increasing procedure-related risks. These findings provide crucial evidence supporting early intervention strategies for PLA, though prudent evaluation of evidence robustness and clinical risks remains imperative before widespread implementation[1].

Qiu et al[1] conducted a study involving 143 patients with PLA, categorizing them into liquefied (84 cases) and non-liquefied groups (59 cases) based on abscess liquefaction status. All participants underwent ultrasound-guided PCD. The results demonstrated a 99.3% overall technical success rate with a 5.59% complication rate, confirming the procedure’s high efficacy and safety profile. Notably, the non-liquefied group demonstrated significantly shorter hospitalization duration, faster fever resolution, and accelerated time to achieve > 50% abscess size reduction compared with the liquefied group across these key metrics, while no statistically significant difference was observed in complication rates between groups. This finding challenges the conventional therapeutic paradigm of awaiting liquefaction, suggesting that early intervention may enhance infection control through timely decompression and improved antibiotic penetration.

Pathophysiological analysis reveals that PLA formation results from dynamic interactions between bacterial pathogens and host immune responses[2,3]. During the initial non-liquefied phase, purulent exudate contains substantial concentrations of viable microorganisms and inflammatory mediators. Early drainage in this critical window serves to not only reduce pathogen load but also disrupt the amplification cascade of inflammatory reactions[4-6]. The real-time imaging guidance provided by ultrasound ensures exceptional precision in puncture trajectory selection, preventing inadvertent damage to critical vascular and biliary structures. This technical advantage enables the maintenance of high procedural success rates with low complication incidence even during the non-liquefied phase of abscess development[7].

Clinical observations demonstrate that patients with PLA frequently exhibit comorbidities such as diabetes and biliary disorders. These compromised individuals demonstrate rapid disease progression, where the conventional delayed drainage approach is associated with suboptimal therapeutic outcomes[8,9]. In the investigation conducted by Qiu et al[1], accelerated recovery timelines observed in the non-liquefaction cohort substantiate the clinical utility of early PCD for this high-risk subpopulation. This interventional strategy reduces healthcare resource utilization through substantial abbreviation of disease duration, as evidenced by quantitative analysis of hospitalization parameters. Notably, the culture positivity rate in this study reached 72%, with Klebsiella pneumoniae accounting for 75.7%. These findings correspond to the etiological distribution patterns documented in other Chinese regions, substantiating the clinical significance of early drainage combined with pathogen-directed antibiotic therapy[10].

Although the findings are encouraging, the inherent limitations of its retrospective design and single-center cohort require careful consideration. The non-liquefied group may have included cases in the early stage of liquefaction. However, the ultrasonographic assessment of the degree of liquefaction is highly operator-dependent, leading to significant interobserver variability in the determination of “non-liquefied” status, which consequently affects the accuracy of group classification. Additionally, the description of “the pus is thin” was vague and lacked clear group allocation, potentially causing ambiguity in interpretation. The study did not report the number of abscesses or efficacy data stratified by abscess size, nor did it compare abscess volume between the non-liquefied and liquefied groups. Furthermore, it failed to adequately control for key covariates such as the anatomical location of the abscesses and underlying conditions (such as glycemic control status) to ensure comparability between the two groups. Notably, diabetic patients accounted for 55.9% of the cohort, and their immune status may significantly influence treatment response. However, this potential confounding factor was not systematically assessed or statistically adjusted for. The reporting of adverse events was also incomplete, omitting common clinical complications such as catheter obstruction and repeated catheter repositioning. For resource-limited settings, the study did not explore the potential economic burden associated with multiple PCD procedures often required for multifocal abscesses. Moreover, non-liquefied abscesses typically contain a smaller volume of pus, yet the specific mechanism and rationale for drainage in such cases were not thoroughly elaborated on.

Current mainstream views have not yet established an optimal timing for needle aspiration, merely recommending “assessment of liquefaction degree” without precise guidelines. While conventional consensus maintains that liquefied abscesses demonstrate better drainage feasibility, the study by Qiu et al[1] revealed superior therapeutic outcomes in the non-liquefied group, challenging the traditional “wait-for-liquefaction” approach. Nevertheless, given the retrospective design of this single-center investigation with inherent methodological limitations and low evidence level, the contradiction between its findings and established clinical perceptions necessitates validation through rigorously designed multicenter prospective randomized controlled trials. Of clinical relevance, a retrospective investigation conducted by Peking Union Medical College Hospital revealed that early PCD (initiated within one week of fever onset or with liquefaction degree < 30%) significantly reduced febrile duration, thereby reinforcing the clinical rationale for this approach. Nevertheless, the evidence base still requires fortification through methodologically rigorous studies to establish practice guidelines[11].

Current evidence supports early PCD as a potential alternative strategy for patients presenting with severe clinical manifestations (including persistent fever or marked leukocytosis) despite the absence of ultrasonographically evident liquefaction. Diabetic patients with PLA, characterized by immunocompromised status, should be considered candidates for more proactive interventions. Pre-procedural glycemic control must be optimized, and postoperative inflammatory markers require vigilant monitoring. For small abscesses (diameter < 3 cm) or cases with mild systemic symptoms, antibiotic therapy remains the preferred initial approach to minimize unnecessary invasive procedures. Serial ultrasound evaluation is recommended during management to dynamically assess liquefaction progression, supplemented by contrast-enhanced computed tomography or elastography when diagnostic ambiguity persists. Multidisciplinary collaboration involving surgery, infectious disease, and radiology teams is critical for formulating individualized treatment plans. In clinical scenarios such as multiloculated abscesses or immunocompromised hosts, risk-benefit analysis of drainage procedures should prioritize therapeutic safety while ensuring clinical efficacy.

CONCLUSION

Qiu et al[1] demonstrated that ultrasound-guided early PCD provides a safe and effective therapeutic strategy for PLA management without requiring delayed intervention until complete abscess liquefaction. This approach not only substantially reduces disease duration but also adheres to the contemporary medical principle of “early intervention for infectious diseases to minimize pathogen burden”. Nevertheless, certain limitations persist, necessitating validation through additional large-scale investigations. Clinicians should adopt patient-tailored treatment protocols through multidisciplinary collaboration in clinical practice, abandoning conventional mechanical waiting strategies for liquefaction. Such paradigm shifts may facilitate the evolution of PLA management from empirical observation to precision-targeted intervention.