Highlights
– In a retrospective single‑center review of 4,563 ultrasound‑guided paracenteses, overall clinically significant hemorrhage occurred in 1.3% (60/4,563).
– Midline catheter placement (through the linea alba) was associated with no hemorrhagic complications (0/230) versus 60 events after lateral placement (60/4,283); p = 0.03.
– The study is hypothesis‑generating: it suggests an anatomic rationale (avascular linea alba) for lower bleeding risk with midline approaches but is limited by retrospective design and potential selection biases.
Background and clinical context
Ascites is a common complication of cirrhosis, malignancy, and heart failure. Diagnostic and therapeutic percutaneous paracentesis is one of the most frequently performed bedside procedures in hospitalized patients with ascites. Although generally safe, paracentesis carries a small but potentially life‑threatening risk of hemorrhagic complications, including abdominal wall hematoma, intraperitoneal bleeding, requirement for transfusion, angiographic embolization, and death.
Anatomically, the lower midline (linea alba) is a relatively avascular fibrous plane, whereas lateral abdominal wall punctures risk traversing the inferior epigastric and other vessels. The study by Miller et al. (2025) tested the hypothesis that a midline approach would reduce clinically significant post‑paracentesis hemorrhage.
Study design and methods
Miller and colleagues conducted a retrospective chart review approved by the University of Chicago Institutional Review Board (IRB 20‑0083). Using administrative diagnosis codes, they identified 1,798 unique patients who underwent ultrasound‑guided percutaneous abdominal paracentesis between January 1, 2011 and January 1, 2020, comprising 4,563 paracentesis events.
Procedure location (lateral vs midline) was available for 4,513 events. The primary outcome was clinically significant hemorrhage defined stringently: computed tomography (CT) evidence of hemorrhage at the procedural site within 7 days that required blood transfusion, angiographic intervention, or resulted in death. Baseline patient variables were extracted: age, sex, BMI, volume drained, hemoglobin, platelet count, INR, serum sodium, creatinine, bilirubin, albumin, and ascites etiology. Among cirrhosis cases (n = 2,497 events), MELD 3.0 and Child‑Pugh scores were calculated where data permitted.
Key findings
Overall results
– Total paracentesis events: 4,563.
– Events with documented procedure location: 4,513.
– Overall clinically significant hemorrhage: 60 events (1.3% of all procedures; 60/4,563).
Location‑specific results
– Midline placement: 230 procedures; hemorrhage events: 0 (0%).
– Lateral placement: 4,283 procedures; hemorrhage events: 60 (≈1.4%).
– Statistical comparison: zero events in midline vs 60 in lateral group; p = 0.03.
Cirrhosis subgroup
– Lateral paracenteses in cirrhosis: n = 2,086; mean MELD 3.0 = 22 (SD 8.46).
– Midline paracenteses in cirrhosis: n = 118; mean MELD 3.0 = 25 (SD 8.13).
– The MELD difference (midline higher) was statistically significant by Mann‑Whitney U test (p ≤ 0.001) though the standardized effect size was small (0.071), indicating minimal practical difference despite statistical significance.
Multivariable analysis
Logistic regression examining baseline variables associated with hemorrhage did not identify clear independent predictors: no variable had an odds ratio with a 95% confidence interval wholly excluding 1. Serum bilirubin approached but did not reach conventional significance (p = 0.07).
Safety and secondary outcomes
All hemorrhage events met the study’s strict definition (CT confirmation plus need for transfusion, angiographic intervention, or death). The authors do not report minor bleeding events that did not reach CT confirmation or did not require intervention; hence, the analysis centers on clinically substantial bleeding.
Interpretation and clinical implications
The findings suggest a meaningful reduction in major post‑paracentesis hemorrhage when catheters are placed via the midline, consistent with the anatomy of the avascular linea alba and avoidance of inferior epigastric vessels encountered in lateral approaches. The absolute difference appears small in population terms (1.3% overall), but the clinical consequences of the events captured (transfusion, angiographic embolization, or death) are significant.
For clinicians, the study highlights a potentially modifiable procedural choice—midline versus lateral access—that may reduce severe bleeding risk. Given the relatively low frequency but high severity of hemorrhagic complications, preferential midline access when technically feasible may be a reasonable strategy, especially in patients at elevated bleeding risk.
Expert commentary: strengths, limitations, and unanswered questions
Strengths
– Large procedural sample size (4,563 events) from a single center with consistent documentation.
– Use of a conservative, clinically meaningful hemorrhage definition (CT evidence plus intervention or death) reduces over‑call of trivial bleeding.
Limitations
– Retrospective, nonrandomized design: operator preference, patient anatomy, and clinical context likely influenced choice of midline versus lateral approach, introducing selection bias. Remarkably, midline patients in the cirrhosis subgroup had slightly higher MELD scores, but residual confounding remains possible.
– Low absolute number of midline procedures (n = 230) and zero events in that group: while statistically significant by comparison, zero‑event groups can inflate type I or II error risk and complicate effect‑size estimation.
– Single‑center data may limit generalizability to centers with different training, ultrasound practices, or patient mixes.
– The strict hemorrhage definition excludes minor bleeds; the study therefore reports on major complications only. Operator technique, needle gauge, catheter size, and number of passes were not detailed and could affect bleeding risk.
Open questions
– Would a prospective randomized trial of midline versus lateral ultrasound‑guided paracentesis confirm these findings? Such a study would need to be large to detect small absolute differences in rare but severe events.
– Are there tradeoffs to midline access (e.g., discomfort, higher risk of bowel puncture in certain anatomies) that were not captured here?
– Can ultrasound identification of abdominal wall vessels and avoidance of epigastric vessels entirely mitigate lateral approach risk, making the difference smaller in centers proficient with vascular mapping?
Practical recommendations
Until prospective randomized data are available, clinicians may consider the following pragmatic approach:
- Prefer midline (linea alba) catheter placement for therapeutic paracentesis when the technique is feasible and ultrasound imaging supports a safe needle trajectory.
- Use real‑time ultrasound to identify pocket of fluid and to avoid visible abdominal wall vessels—mapping the inferior epigastric vessels on color Doppler can inform lateral site choice.
- Apply the study’s conservative outcome perspective: educate teams that major hemorrhage is uncommon but serious, and maintain a low threshold for imaging and intervention when bleeding is suspected.
- Document procedural site, number of passes, catheter size, and any immediate bleeding to help future quality reviews.
Conclusion
This large retrospective review suggests that midline, ultrasound‑guided paracentesis through the linea alba may be associated with fewer clinically significant hemorrhagic complications compared with lateral approaches. The biologic plausibility is strong (avascular midline), but the evidence is hypothesis‑generating given the retrospective design, potential selection bias, and small number of midline procedures. Prospective studies or randomized trials would help confirm whether procedural site selection should become a formal component of paracentesis safety protocols.
Funding and clinicaltrials.gov
The published report does not list external funding. The study was conducted with institutional review board approval (University of Chicago IRB 20‑0083). No clinicaltrials.gov registration applies to this retrospective analysis.
References
1. Miller J, Dinh T, Pieroni C, Velo A, Pohlman A, Ajmani G, Wolfe K, Patel B, Kress JP. Lateral Versus Midline: A Retrospective Review of Paracentesis Site Location and Risk of Hemorrhagic Complication. Crit Care Med. 2025 Dec 1;53(12):e2698-e2705. doi: 10.1097/CCM.0000000000006883. Epub 2025 Sep 26. PMID: 41020659.
Author note
This article summarizes and interprets the findings of Miller et al. (2025) and provides clinical context for bedside practitioners. It is not a substitute for clinical judgment or institutional protocols. Readers should consult local guidance and patient‑specific factors when selecting paracentesis technique.
