Role of Autologous Blood Clot Seal in Reducing the Incidence of Pneumothorax Post CT-guided Lung Biopsy: A Randomized Control Trial

Abstract

Objectives

The objective of this research study was to assess the safety and efficacy of employing autologous blood clot seal (ABCS) for lowering the occurrence of pneumothorax (PTX) after computed tomography (CT)-guided percutaneous lung biopsy.

Methods

A prospective randomized controlled trial involving 100 patients, approved by our hospital's institutional ethics committee and registered in the Clinical Trial Registry of India (CTRI/2021/04/032746), was conducted. Adult patients undergoing percutaneous lung biopsy were included. Randomization of the patients was done, and they were allocated to two groups: Group A received biopsies with the ABCS application, while in Group B patients, biopsies were done without the use of ABCS. An 18G semi-automatic coaxial biopsy system was utilized. In Group A, ABCS was administered through the guiding needle upon removal of the biopsy gun. PTX occurrence was assessed immediately post-biopsy and at a 4-hour follow-up.

Results

Among the 50 patients in Group A, PTX developed immediately in 4 (8%) patients, with no change in frequency at the 4-hour follow-up. In contrast, among the 50 patients in Group B, PTX occurred immediately in 15 (30%) patients, and the frequency increased to 34% (17/50) at the 4-hour follow-up. The incidence of PTX was significantly lower in ABCS recipients both immediately and at the 4-hour follow-up (p-value = 0.009 and p-value = 0.003, respectively).

Conclusion

ABCS is a simple, affordable, and safe intervention that lowers the incidence of PTX following CT-guided percutaneous lung biopsy. This method holds promise for improving patient outcomes in clinical practice.

 

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Keywords

lung biopsy - autologous blood clot seal - pneumothorax - interventional radiologist

Introduction

Percutaneous computed tomography (CT)-guided percutaneous lung biopsy serves as a reliable and indispensable method for acquiring tissue samples to diagnose pulmonary abnormalities efficiently and securely.[1] For CT-guided percutaneous lung biopsy, pneumothorax (PTX) is the most common side effect, with a reported prevalence ranging from 17.6 to 26.6%, depending on technique.[2] [3] The incidence of PTX requiring the insertion of a chest tube is substantially less common, ranging from 1 to 14.2%.[4] [5] [6] [7]

Lesion size and depth, age, male gender, smoking history, presence of emphysema, lesions in subpleural location, more pleural passages, lateral puncture of pleura, biopsy coaxial needle traversing a lung fissure, use of a large coaxial needle, absence of pleural thickening, lower lobe lesions, shallow angle of pleura puncture, and interventionists with less experience have all been associated with PTX risk.[8] The frequency of PTX complicating CT-guided lung biopsy procedures can escalate a substantial number of outpatient interventions into inpatient scenarios and is particularly challenging for patients with compromised pulmonary reserve, who may be unable to tolerate even minor PTX occurrences.

Several methods have been proposed to lower the risk of PTX, ranging from breath holding during the puncture, avoiding transgression of fissures, patient positioning strategies to sealing the biopsy needle tract with application of fibrin glue, blood clot seal, and isobutyl-2-cyanoacrylate. Several studies observed that in patients with lung lesions that “bloomed” in lung biopsy under fluoroscopic guidance, PTX was not common and determined that the hemorrhage apparently prevented air leak by filling up the air spaces and sealing the biopsy tract. Based upon these observations, they first reported the application of autologous blood clot seal (ABCS) post lung biopsy in 25 high-risk patients. Subsequent studies explored ABCS, showing a notable 20 to 30% reduction in PTX frequency.[9] [10] [11]

This procedure's safety and efficacy have only been evaluated in a small number of studies, and other research has mostly focused on the necessity of advanced intervention for treating PTX in patients and the efficacy of those interventions. Currently, there are no guidelines to advocate the use of any tract sealing techniques after CT-guided percutaneous lung biopsy, and institutions consider using tract sealing on a case by case basis, usually in selected high-risk patients. This study aimed to assess the effectiveness of applying the ABCS in preventing the development of PTX when used as a routine in all patients undergoing CT-guided percutaneous lung biopsy, irrespective of risk status, and to determine whether this technique decreases the requirement for patients undergoing CT-guided lung biopsy to have thoracic tubes inserted.

 

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Methods

The institutional ethical committee of the hospital gave its approval to this study, and it was also registered in the Clinical Trial Registry of India (CTRI) under registration number CTRI/2021/04/032746. Written consent was obtained from each patient prior to any biopsy procedure.

This study is a randomized controlled trial (RCT) which aims to assess the effectiveness and safety of ABCS following CT-guided percutaneous lung biopsy to mitigate the risk of PTX occurrence. A block randomization list was generated from an online tool[12] and the patients were allocated accordingly to Group A and Group B. Group A patients received the autologous blood clot, whereas Group B patients did not. The sample size of our study was 100, calculated from the “Power Calculator for Binary Outcome Superiority Trial by Sealed Envelope Ltd.”[13] Group A consisted of 50 patients, while group B had 50 patients.

An interventional radiologist with over 5 years of expertise in performing CT-guided percutaneous lung biopsies performed all biopsy procedures. A diagnostic contrast-enhanced CT of the chest was performed in all patients. The Siemens SOMATOM Sensation Open Multidetector Row 32-Slice CT scanner was the CT machine used in the current study. Examining the preliminary images allowed us to determine the lung lesion's location and size. The lesion was located either deep in the parenchyma (aerated lung separated lesions from the pleura) or in relation to the pleural (pleura directly contacted the parenchymal lesions). The presence of emphysema was noted. These preliminary images were also used for planning the biopsy's approach direction, patient position, and level of entry for the needle to provide the most straight access path possible, avoiding bullae and fissures and passing through the least amount of aerated lung possible. The patient's position during the biopsy was determined by the characteristics of the lesion such as size and site. Both local anesthetic and skin antisepsis were applied. An 18G semi-automatic coaxial biopsy system was used. Throughout the process, intermittent CT scans were taken to verify the needle's position inside the lesion and to track its path. A specimen was taken once the needle tip was confirmed to have reached the lesion.

In the ABCS group (Group A), antecubital veins were used to extract 6.0 to 8.0 mL of blood prior to the procedure, which was then allowed to coagulate in the syringe for approximately 30 minutes in an upright position to make the blood patch. In Group A patients, at the level of the biopsied nodule, 0.5 to 3.0 mL of clot and 0.5 to 1.5 mL of supernatant were injected while removing the coaxial sheath, sealing the complete pathway to the visceral pleura ([Fig. 1]). Without administering an ABCS injection, the coaxial sheath was quickly removed from patients in Group B. All patients were kept depending on the biopsy site after the procedure.

Fig. 1 (A) Axial CT shows the coaxial sheath within the lesion (size 35 × 24 mm) in the upper lobe of the right lung. (B) Axial CT shows the biopsy track filled up to the visceral pleura with a hyperattenuating fresh blood clot (arrow) after ABCS application. Pneumothorax did not develop. ABCS, autologous blood clot seal; CT, computed tomography.

Prior to the coaxial needle being removed, CT of the chest was taken during the postprocedure follow-up, while the patient was still on the table to look for the presence of PTX ([Fig. 2]). Mild pneumothoraces (<2 cm) were managed conservatively and when possible, aspirated through the coaxial needle on the table followed by a repeat CT at 5 minutes. Large pneumothoraces (>2 cm), or repeat accumulation after aspiration in mild PTX, or an increase in size of a mild PTX was managed by tube drainage on the table. A posteroanterior (PA) view radiograph of the chest was obtained immediately after the biopsy, and the patient was then admitted to a short-stay unit for 4 hours, with the sampled side in the dependent position. A repeat PA radiograph of the chest was obtained at 4 hours. Patients without a PTX were discharged. For patients who were symptomatic, had large pneumothoraces (>2 cm in axial thickness), and/or showed PTX progression at any stage, a chest tube was inserted. Patients who experienced PTX following the biopsy process but did not need treatment were monitored closely while receiving nasal oxygen. These patients were discharged after 24 hours if stable and advised to report immediately should any symptoms like dyspnea and/or chest discomfort appear. The following flow diagram summarizes the methodology of this RCT ([Fig. 3]).

Fig. 2 (A) Axial CT shows the coaxial sheath within the lesion (size 31 × 29 mm) in the upper lobe of the right lung. Pneumothorax was not present at this stage. (B) Axial CT shows the biopsy track filled up to the level of visceral pleura with a hyperattenuating fresh blood clot (arrow) injected into the needle from the coaxial system. Immediately after the ABCS application, the level of pneumothorax was measured as 5 mm on the table and no significant increase was observed at follow-up. ABCS, autologous blood clot seal; CT, computed tomography.

Fig. 3 Flow diagram showing methodology of the study.

Statistical Analysis

The collected data were entered into the Microsoft Excel spreadsheet. It was then coded and exported to the data editor of the Statistical Package of Social Sciences (SPSS) version 23.0. Frequencies and percentages were used to characterize the categorical variables, while the continuous variables were described as standard deviation and mean. The chi-square test was employed for analysis of the relationship between the two categorical variables. To compare a continuous variable between two groups, the t-test was employed. Statistical significance level was accepted as p <0.05.

 

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Results

Our study population comprised 68 (68%) males and 32 (32%) females, with a male:female ratio of 2.1:1. In our study, patients had a mean age of 62.43 ± 10.14 years. The age range was 29 to 88 years. In addition, 61% of patients had a parenchyma-based lesion, while 39% had a pleural lesion. Emphysema was present in 41% of patients at the baseline. Prone position (52%) was the most common position, followed by supine position (34%). The majority of patients (96%) had only one pass of coaxial biopsy needle insertion. One pass was performed in 47 patients (49%) from Group A and 49 patients (51%) from Group B. Two passes were performed in 3 patients (75%) from Group A and 1 patient (25%) from Group B.

Immediately after the biopsy procedure, 19% (19/100) of patients developed PTX, whereas the PTX rate at 4 hours was 21% (21/100). The majority of immediate post-biopsy PTX patients were managed conservatively, 57.9% (11/19). Aspiration was done in 15.8% (3/19) and chest tube drainage was done in 26.3% (5/19) patients. At 4-hour follow-up, one additional patient developed a mild PTX for which no intervention was needed, and in one additional patient a chest tube was inserted. ABCS was applied to 50% (50/100) of patients. The two groups of patients (those who were subjected to ABCS and those who were not subjected to ABCS) were comparable with respect to the distribution of gender, age, presence of emphysema at baseline, location of lesions, number of passes, patient position, and number of samples obtained. There was no correlation of lung biopsy using ABCS with age, gender, emphysema, location of lesion, number of passes, patient position, and number of samples obtained ([Table 1]).

Table 1 Comparison of various parameters between group A (ABCS applied) and group B (ABCS not applied)

Characteristic	Type	ABCS applied		p-Value
		No (Group B) n = 50	Yes (Group A) n = 50
Gender, n (%)	Male	31 (45.6%)	37 (54.4%)	0.28
	Female	19 (59.3%)	13 (40.7%)
Age (y), mean ± SD		62.6 ± 11.3	62.4 ± 8	0.9
Presence of emphysema, n (%)	No	28 (47.4%)	31 (52.6%)	0.69
	Yes	22 (53.6%)	19 (46.4%)
Location of lesion, n (%)	Pleural	17 (43.6%)	22 (56.4%)	0.41
	Parenchyma	33 (54.1%)	28 (45.9%)
No. of passes, n (%)	1	49 (51.1%)	47 (48.9%)	0.62
	2	1 (25.0%)	3 (75.0%)
Patient position, n (%)	Supine position	16 (47.1%)	18 (52.9%)	0.53
	Prone position	29 (55.8%)	23 (44.2%)
	Lateral decubitus	5 (42.8%)	9 (57.2%)
No. of samples obtained, n (%)	3	0 (0.0%)	1 (100.0%)	0.69
	4	11 (52.3%)	10 (47.7%)
	5	34 (52.3%)	31 (47.7%)
	6	5 (38.4%)	8 (61.6%)

Abbreviations: ABCS, autologous blood clot seal; SD, standard deviation.

Of the 50 patients who received ABCS (Group A), immediately after biopsy, PTX developed in 4 patients (8%) and none (0%) required chest tube placement, and at 4-hour follow-up, the frequency of PTX and chest tube placement in Group A patients remained same (8 and 0%, respectively). Of the 50 patients who did not receive an ABCS (Group B), PTX developed immediately in 15 patients (30%) and 5 patients (33.3% of pneumothoraces); 10% overall) required thoracic tube placement immediately, and at 4-hour follow-up PTX was seen in 17 patients (34%), and chest tube insertion was required in one additional patient, bringing the total to 6 (35.3% of pneumothoraces; 12% of all biopsies) ([Table 2] and [Figs. 4] and [5]).

Table 2 Relationship between pneumothorax development and chest tube insertion (immediately and at 4-hour follow-up) in relation to ABCS application

ABCS applied	Pneumothorax immediately post-biopsy, n (%)		Chest tube placement immediately, n (%)	Pneumothorax at 4-hour follow-up, n (%)		Chest tube placement at 4-hour follow-up, n (%)
	Absent	Present		Absent	Present
No (Group B), n = 50	35 (70.0%)	15 (30.0%)	5 (33.3%)	33 (66.0%)	17 (34.0%)	6 (35.3%)
Yes (Group A), n = 50	46 (92.0%)	4 (8.0%)	0 (0%)	46 (92.0%)	4 (8.0%)	0 (0%)
P -value	0.009		0.052	0.003		0.02

Abbreviation: ABCS, autologous blood clot seal.

Fig. 4 Bar chart depicting relationship between pneumothorax immediately post-biopsy and ABCS applied. ABCS, autologous blood clot seal.

Fig. 5 Bar chart depicting relationship between pneumothorax at 4 hours and ABCS applied. ABCS, autologous blood clot seal.

The frequency of PTX development was significantly lower in ABCS recipients both immediately and at 4-hour follow-up and a statistically significant difference was present. (p-value of 0.009 and 0.003, respectively). In total, in the ABCS group (Group A), 46 patients had no PTX, 4 had mild PTX, and no patient had massive PTX, whereas, in the no ABCS group (Group B), there were 33 patients without PTX, 11 with mild PTX, and 6 with massive PTX.

The frequency of chest tube placement at 4-hour follow-up was significantly lower in Group A (p-value = 0.02). However, immediately after biopsy, Group A had fewer chest tube placements overall, but there was no statistically significant difference (p-value = 0.052).

 

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Discussion

Post-lung biopsy PTX is a frequently encountered complication that increases the morbidity of an otherwise daycare procedure. It continues to affect patient care despite meticulous planning, selection of biopsy tract, appropriate patient positioning, and breath-hold. Our study's objective was to evaluate the safety and effectiveness of ABCS application in decreasing the complication of PTX occurrence after CT-guided lung biopsy. Usual maneuvers to reduce PTX incidence included patient positioning with planning the suggested biopsy track's route to avoid fissures, blebs, and large vessels, and, when present, following pleural tags. Using perpendicular entry, breath-hold during needle advancements and biopsy and post-biopsy-dependent positioning of biopsy site were followed in all patients in both groups. The incidence and size of PTX were significantly reduced, as well as the requirement for chest tube drainage with the use of ABCS, both immediately post-biopsy and at the 4-hour follow-up, according to the data.

Our study aimed to assess if using ABCS lowers the frequency of PTX after CT-guided percutaneous lung biopsy. Patients in whom ABCS was applied had a significantly lower incidence (8.0%) of immediate post-biopsy PTX as compared with those in whom ABCS was not applied (30.0%), which was statistically significant (p-value: 0.009). Also, at 4 hours, patients in whom ABCS was applied had again a significantly low incidence (8.0%) of post-biopsy PTX as compared with those in whom ABCS was not applied (34.0%), and this reduction in PTX was statistically significant (p-value: 0.003). This was in accordance with various previous studies. Lang et al reported that the frequency of PTX was considerably decreased by using ABCS to seal biopsy tracks, especially after the biopsy procedure of deep lung lesions.[11] According to Malone et al, using the blood patch decreased the rate of PTX from 35 to 26% (p-value of 0.12) but the reduction was not significant.[14] A statistically significant decrease in the percentage of PTX (p-value: 0.002) was reported by Clayton et al in patients who received blood patch application (28%) versus those who did not (42%).[15] Similarly, according to Graffy et al, following CT-guided lung biopsy, patients who received a parenchymal blood patch developed a significantly lower rate of PTX (30%) compared with those who did not (44%; p-value: 0.0001).[10] It was also confirmed by Turgut et al that PTX rate was considerably less frequent in patients who received an autologous blood patch (14.1%) compared with those who did not (26.3%; p = 0.01).[16] In our study, immediately after biopsy, Group A had fewer chest tube placements overall, but there was no statistically significant difference (p-value = 0.052). This was in discordance with various studies; Malone et al found that the percentage of PTX patients who needed a chest tube to be placed was significantly lowered, from 18 to 9% (p = 0.048).[14] A statistically significant decrease in chest tube placement (p < 0.001) in patients who received a nonclotted blood patch (4%) versus those who did not (16%) was found by Clayton et al.[15] According to Graffy et al, patients had a much reduced rate of chest tube placement who received an intraparenchymal blood patch (8.9%) post CT-guided lung biopsy compared with those who did not (24.1%; p < 0.0001).[10] Turgut et al also claimed that compared with patients who did not receive the blood patch (11.1%), a significantly lower percentage of patients (7.7%) needed to have a chest tube placed (p = 0.015).[16] The statistical insignificance of our result could be attributed to the smaller incidence of chest tube placements in our study compared with the above-mentioned studies and the smaller sample size. There is a need for a larger study with sufficient statistical power to comprehensively assess the impact of ABCS on critical outcomes such as chest tube placement or hospitalization.

Various other materials have been employed to seal the biopsy needle tract in patients undergoing CT-guided percutaneous lung biopsy. The injection of 0.9% NaCl has been used in a small number of studies and has very few adverse effects, but it has been shown to be inconsistent.[17] The hemostat gelatin powder has the drawback of taking longer to prepare the combination, which extends the procedure's overall duration. If the absorbable gelatin powder spills into intravascular compartments, there is also a chance of embolization. Furthermore, careful administration of gelatin powder is required due to the dangers of infection and abscess formation.[18] Plug-based methods, including the hydrogel plug, are priced similarly to fibrin glue but have not been demonstrated to be more effective than ABCS at lowering the frequency of PTX while adding to the procedure cost at the same time.[19] In contrast, the ABCS method seals the needle tract using the patient's own blood, which is collected prior to the biopsy. The cost and duration of the process are not increased by this strategy. Furthermore, it does not put the patient at risk for the side effects that could come from using synthetic materials. The frequency of PTX in our study group decreased by more than half with ABCS administration, demonstrating that this method provides affordable and efficient means for the prevention of PTX, and at the same time, unlike the usage of other synthetic materials, the process is also simple to apply. In our study, none of the ABCS participants experienced any complications or side effects. These findings show that the ABCS technique is a safe and reliable method for preventing the PTX development in patients undergoing CT-guided lung biopsy.

 

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Conclusion

Although percutaneous lung biopsy with CT-guidance is a safe procedure, PTX is a frequent side effect. Even though PTX is typically clinically minor in most patients, until the patient stabilizes, more imaging and monitoring may be required. Patients may require the insertion of a chest tube in comparatively few circumstances. This not only poses a serious issue for the patient, but it also raises the cost of care. It is clear that strategies that can lower the frequency of PTX following CT-guided lung biopsy are crucial for overall patient care. Therefore, it is preferable to use ingredients that are cheap, almost side-effect-free, and simple to apply. The ABCS application was successfully used in this study, and the process is straightforward and inexpensive. ABCS is a simple, affordable, and safe strategy for reducing the frequency of PTX.

 

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Conflicting Interest

None declared.

Ethical approval

There were no ethical considerations to be considered in this research.

Funding

None.

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Publication History

Article published online:
03 July 2025