Parenchymal blood patching in percutaneous computed tomography-guided lung biopsy: A retrospective analysis of pneumothorax management

Abstract

Introduction and Objective:

CT-guided percutaneous lung biopsy is a widely used diagnostic tool for pulmonary lesions, but it carries a significant risk of pneumothorax. Various techniques have been explored to minimize this complication, including the use of autologous intraparenchymal blood patching. This study aims to evaluate the effectiveness of parenchymal blood patching in reducing pneumothorax rates in percutaneous CT-guided lung biopsies.

Materials and Method:

This retrospective study included all patients who underwent percutaneous CT-guided lung biopsy at a tertiary care hospital in Northeast India, from January 2023 to January 2025. Patients were categorized into two groups: those who did not receive a blood patch and those who received a blood patch.

Results and Conclusion:

A total of 121 patients who underwent CT-guided lung biopsy were included in the study. Among the 39 patients who did not receive a parenchymal blood patch, pneumothorax occurred in 12 cases (30.7%), of which 7 required chest tube drainage and 5 underwent aspiration. In contrast, among the 82 patients who received a parenchymal blood patch, pneumothorax developed in 7 cases (8.5%). Of these, 5 patients required chest tube drainage, while 2 had minimal, non-progressive pneumothorax that required no intervention. Hospitalization was needed in 7 patients in the non-blood patch group and in 5 patients in the blood patch group. A chi-square test showed a statistically significant reduction in pneumothorax incidence in the blood patch group (P = 0.04). However, no statistically significant difference was found in hospitalization rates between the two groups (P = 0.32). Parenchymal blood patching is an effective technique in CT-guided lung biopsies, significantly reducing pneumothorax rates.

INTRODUCTION

Percutaneous computed tomography (CT)-guided lung biopsy is an essential diagnostic tool for evaluating pulmonary lesions. However, one of its most common complications is pneumothorax,[1,2] which can necessitate additional interventions such as aspiration or chest tube placement.[1] Pneumothorax rates after percutaneous biopsy range from 15 to 25.9%.[1,2,3,4] Most post-biopsy pneumothoraces are small and resolve spontaneously[5]; larger pneumothoraces require drainage. Various techniques have been proposed to reduce pneumothorax risk, including post-procedure rapid rollover[6,7] to modifications in biopsy technique by using smaller gauge needles[8] and biopsy tract sealing. Parenchymal blood patching, wherein autologous blood is injected into the biopsy tract, has been suggested as a method to prevent air leakage and subsequent pneumothorax formation.[9,10,11]

Recent studies have demonstrated that intraparenchymal blood patching decreases pneumothorax-related complications following percutaneous CT-guided needle biopsy.[9,10,11] This study evaluates the efficacy of parenchymal blood patching in CT-guided lung biopsies by comparing post-procedure pneumothorax incidence between patients who received a blood patch and those who did not.

MATERIALS AND METHODS

Study design and population

This retrospective study included all patients who underwent percutaneous CT-guided lung biopsy at Narayana Superspeciality Hospital, Guwahati, India, from January 2023 to January 2025. Patients were categorised into two groups: those who did not receive a blood patch (January 2023 to August 2023, n = 39) and those who received a blood patch (September 2023 to January 2025, n = 82).

Inclusion criteria

• All patients who underwent CT-guided lung biopsy, regardless of age.

Exclusion criteria

• Patients with pre-existing pneumothorax, pleural effusion, or an indwelling chest drain.

Biopsy procedure

All biopsies were performed by a single operator under local anaesthesia using 2% lignocaine. A 20-gauge coaxial biopsy gun (Temno/Bard and Terumo) was utilised. If pneumothorax developed during the procedure, biopsy and parenchymal blood patching were still performed.

Parenchymal blood patching technique

• 10 mL of autologous blood was drawn from the patient’s IV catheter at the time of securing IV access. The syringe was left undisturbed to allow for the blood to clot.

• After obtaining the biopsy samples and before removing the coaxial introducer needle, plasma was slowly removed from the autologous blood in the syringe and the remaining clots/blood was slowly injected through the coaxial introducer needle as it was removed.

• Blood was injected continuously during needle removal to fill the biopsy tract, with a 2–3 mL bolus placed in the immediate subpleural lung. A total of 5–6 ml of blood was injected depending upon the length of the tract.

• A post-procedure CT scan confirmed blood patch placement and pneumothorax status.

• Patients were positioned biopsy-side down post procedure.

Image 1 is a set of CT images of a lung biopsy and post-biopsy parenchymal blood patching from one of the cases included in this study. Illustration 1 shows the technique of parenchymal blood patching in a step-by-step manner.

Image 1.

a: Non-contrast HRCT image shows a mass lesion with irregular margins in apico-posterior segment of upper lobe of left lung. b: Non-contrast HRCT image shows the biopsy needle within the lesion. c: Non-contrast HRCT image after post-biopsy parenchymal blood patching shows ground glass opacities around the mass suggesting the blood patch without any pneumothorax

Illustration 1.

Parenchymal blood patching

Follow-up protocol

• Patients were observed for 4 hours with bed rest, avoiding coughing or straining.

• If pneumothorax was detected immediately post procedure, a chest X-ray was performed after 1 hour and repeated after another hour.

• Decisions regarding aspiration or chest tube drainage were made based on pneumothorax progression and symptoms.

• Patients requiring chest tube placement were admitted.

• Asymptomatic patients without pneumothorax after 4 hours were discharged without further imaging.

RESULTS

A total of 121 patients were included in the study, with 39 patients in the non-blood patch group and 82 patients in the blood patch group. Key findings include:

Parameter	Without blood patch (n=39)	With blood patch (n=82)
Average Age	66.5 years	63.2 years
Male: Female Ratio	35:4	70:12
Coexisting Emphysema	21	39
Pneumothorax Cases	12	7
Chest Tube Drainage	7	5
Aspiration	5	0 (2 had minimal non-progressive pneumothorax requiring no further treatment)
Hospitalisation	7	5

The average age was 66.5 years in the non-blood patch group and 63.2 years in the blood patch group. There was a male predominance in both groups, with a male-to-female ratio of 35:4 in the non-blood patch group and 70:12 in the blood patch group. The higher male predominance in both groups could be attributed to higher smoking rates and emphysema prevalence in males; however, no significant difference in pneumothorax rates was seen on the basis of age or gender.

Coexisting emphysema was more frequent in the non-blood patch group (21 patients) compared to the blood patch group (39 patients). Pneumothorax occurred in 12 patients (30.7%) in the non-blood patch group, while only 7 patients (8.5%) in the blood patch group developed pneumothorax. Among those who developed pneumothorax, chest tube drainage was required in 7 patients in the non-blood patch group and 5 patients in the blood patch group. Aspiration was performed in 5 cases in the non-blood patch group, whereas no aspiration was required in the blood patch group. Two patients in the blood patch group had minimal, non-progressive pneumothorax that did not necessitate any intervention. Hospitalisation was needed for all those patients who underwent chest tube drainage: 7 patients in the non-blood patch group and 5 patients in the blood patch group.

Statistical analysis using a Chi-square test revealed a significant reduction in pneumothorax incidence in the blood patch group (p = 0.04). However, a t-test showed no significant difference in hospitalisation rates between the two groups (p = 0.32).

DISCUSSION

Blood patching to reduce post-lung biopsy pneumothorax was first introduced by McCartney and his colleagues.[12] Many studies have since assessed this technique to mitigate the incidence of pneumothorax after lung biopsy. The present study was conducted to ascertain the effectiveness of parenchymal blood patching technique, and it clearly demonstrates that parenchymal blood patching significantly reduces pneumothorax rates following CT-guided lung biopsy. The blood patch technique helps seal the biopsy tract, reducing air leakage and minimising the need for interventions such as chest tube placement.[12,13]

The overall pneumothorax rate in our study was 30.7% in the non-blood patch group and 8.5% in the blood patch group. These findings align with previously published data. A meta-analysis by Heerink et al.[1] reported an overall pneumothorax rate of 25.3% across multiple CT-guided lung biopsy series. Similarly, Huo et al.[3] reported rates ranging from 20% to 25%, depending on lesion size and depth. Vachani et al.,[2] in a large population-based study, noted a pneumothorax rate of 15.3%, with 6.6% requiring chest tube insertion. Our non-blood patch group falls within the upper range of these values, possibly due to a higher proportion of patients with emphysema (53.8%) and the use of larger core needles (20-gauge) in all cases.

The marked reduction in pneumothorax rate to 8.5% in the blood patch group mirrors findings from studies employing similar techniques. Turgut et al.[10] and Clayton et al.[9] reported pneumothorax rates of 8.9% and 7.7%, respectively, following parenchymal blood patching. Li et al.,[14] in a recent meta-analysis, reported a pooled pneumothorax rate of 8.4% in blood patch groups across studies. These consistent outcomes suggest that intraparenchymal blood patching significantly lowers pneumothorax incidence. Furthermore, studies like Jain et al.[11] and Mendoza et al.[15] demonstrated both decreased chest tube requirement and overall improved post-procedural outcomes with the technique. Choudhury[16] described the use of intraparenchymal blood patching for both lung and mediastinal lesions, demonstrating a significant reduction in pneumothorax rates, reinforcing our findings. Boskovic et al.[17] conducted a comprehensive analysis involving over 6,000 biopsies and found an overall pneumothorax rate of 20.5%, which aligns closely with the 20.5% rate observed in our non-blood patch group. No significant differences were noted in pneumothorax incidence based on gender or age, aligning with previous research that suggests these factors do not independently impact complication rates.[1,2,3,4,5]

In this study, the hospitalisation rates did not differ significantly between the two groups, despite the reduced incidence of pneumothorax in the blood patch group. This apparent discrepancy could be attributed to the management protocol at our institution. All patients who required chest tube drainage for pneumothorax were admitted for closer monitoring. As this was a retrospective analysis, the detailed documentation of the length of stay for each patient was not available.

However, the findings should be interpreted with certain limitations in mind. The study’s retrospective nature limits the ability to establish causality, and the single-centre design may restrict generalisability. Although lesion size and pleural distance are known predictors of pneumothorax risk in CT-guided lung biopsy, these data were not consistently available in our retrospective series. Many patients were referred from outside hospitals and did not undergo pre-procedural CT imaging at our institution, limiting our ability to extract these measurements. This represents a limitation of the study. Future prospective trials with larger cohorts and long-term follow-up are needed to validate these results and assess the long-term benefits of parenchymal blood patching.

CONCLUSION

Parenchymal blood patching is a valuable technique in CT-guided lung biopsies, significantly reducing pneumothorax rates. Incorporating this method into routine practice may enhance patient outcomes and reduce procedure-related complications. Future multicentre prospective studies are warranted to further substantiate these findings.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.