FormalPara Key Summary Points

Why carry out this study?

The study aimed to describe a case series at a tertiary level referral center that performs medical thoracoscopy with talc poudrage in patients with pneumothorax.

The study evaluated the resolution times of the pleural air leak and the recurrence rates in the time following the procedure.

What was learned from the study?

Medical thoracoscopy with talc poudrage (MT with TP) can be used with the intent to perform a pleurodesis for the patient with pneumothorax once properly selected.

MT with TP is a procedure with a low rate of complications in the series described.

Our study demonstrated a low pneumothorax recurrence rate compatible with the previous literature.

Introduction

Medical thoracoscopy (MT) is a minimally invasive procedure that enables direct imaging of the pleural space and intrathoracic structures, directly visualized pleural biopsies and therapeutic interventions. MT, along with bronchoscopy, is one of the primary endoscopic techniques used in interventional pulmonology in current clinical practice.

In contrast to video-assisted thoracoscopic surgery (VATS), which is carried out in an operating room, under general anesthesia, with selective bronchial intubation, MT can be carried out in an endoscopic suite under local anesthesia and mild to moderate sedation (non-operating room anesthesia, NORA) [1, 2]. The most frequent application of MT is in the investigation of unexplained exudative pleural effusions. Chemical pleurodesis and mechanical adhesiolysis are frequent additional indications of MT [3]. Talc poudrage (TP) is a pleurodesis technique performed during a thoracoscopy that involves the intrapleural instillation of sterile talc by insufflation or spray delivery [4,5,6,7]. TP can be used in cases of recurrent pleural effusion or pneumothorax (PNX); for the latter indication, it can be used both as a treatment aimed at preventing relapses of PNX and as a therapeutic option aimed at treating the acute event, when the pulmonary breach may still be patent [8,9,10,11].

Primary spontaneous pneumothorax (PSP), which occurs in the absence of underlying lung disease, and secondary spontaneous pneumothorax (SSP), defined by the presence of a known underlying lung pathology, are the two main kinds of PNX [12,13,14,15,16,17]. For both of them, recurrence is frequently seen within 5 years of the first episode, with a probability at least one recurrence of 32% after a single episode of PSP [18,19,20] and 13–39% for SSP [11, 18, 21]. Additionally, for patients with chronic obstructive pulmonary disease (COPD), each subsequent PNX is associated with a 3.5-fold increase in mortality [18, 22].

MT is a safe procedure with low mortality rates and complications, which can be performed on fragile patients, those unable to withstand general anesthesia and elevated surgical stress [23,24,25].

The growing effort made by interventional pulmonologists to provide less invasive procedures in order to decrease complications and length of hospital stay (LOS) for comorbid patients who are frequently unable to tolerate elevated surgical stress is what is guiding the increase in the geographic spread of professionals who perform MT [26, 27]. This process has the added benefit of significantly reducing medical care-related costs [9, 28, 29].

We present here a retrospective study on patients who underwent therapeutic MT with TP for the treatment of a PNX. There are few studies analyzing the role of MT in primary or secondary spontaneous PNX, and none evaluating MT in other classified PNX entities such as iatrogenic and traumatic PNX [8, 9, 30]. We aim to evaluate both short- and long-term results following the care of this cohort of patients.

Methods

Patients

This is a retrospective study on human patients, including participants affected by PNX who underwent MT under local anesthesia and deep sedation at the Santa Maria della Misericordia Academic Hospital in Udine from June 2008 to September 2021. All patients with incomplete data were excluded. All participants provided informed consent for data collection in anonymized form. This study protocol was reviewed and approved by Comitato Etico Unico Regionale (CEUR) per la Regione Friuli Venezia Giulia, approval number 37300. Informed consent was obtained from all patients (or their parent/legal guardian where appropriate) regarding the recording of their data in anonymized form. The study was performed in accordance with the Helsinki Declaration of 1964, and its later amendments.

Procedure

Before undergoing MT, each patient underwent basic blood chemistry and coagulation tests. Anticoagulant and antiplatelet therapy, except acetylsalicylic acid prescribed for secondary cardiovascular prevention, was stopped at an appropriate interval of time [31]. Each patient gave informed consent to the procedure.

On the day of the procedure, a thoracic ultrasound examination was performed to identify the ideal area to access the pleural cavity. In light of the pathological condition of PNX treated here, it was not possible to identify pockets of pleural fluid, and the access site was identified by the absence of pleural sliding at the level of the ultrasound field observed [32].

At the start of the procedure, the patient received a mixture of sedative and pain-relieving drugs intravenously. Depending on the anesthesiologist assisting the procedure, midazolam, propofol, fentanyl, and ketamine were used in various combinations and proportions throughout the procedure. Sedation aimed to obtain a level of depth sufficient to maintain spontaneous ventilation without wakefulness. No airway management device was used in any procedure. From the beginning of the procedure, all patients received oxygen therapy via a Venturi mask or reservoir.

The patients were placed in a lateral position, with the affected side facing upward. The entry site was decided with a thoracic ultrasound aid and was located between the posterior and anterior axillary lines. Each patient received local anesthesia with 10 or 20 ml of lidocaine 1% in order to anesthetize the parietal pleura, the skin, and the subcutaneous tissue. Access to the pleural space was obtained through a 2-cm-wide skin incision and subsequent dilation of the tissue planes up to the parietal pleura with blunt-tipped scissors. A trocar with a pointed stylet (Richard Wolf, Knittlingen, Germany) was inserted into the generated tract. Subsequently, the stylet was removed in order to have access to the pleural cavity. All the procedures were carried out using a rigid thoracoscope (Karl Storz Endoskope, Germany) with rigid accessory instrumentation. The procedure, as per local standard, involved the inspection of the pleural cavity aimed at describing pleuro-parenchymal anomalies, without carrying out specific interventions on any findings (e.g., bullae). Talc poudrage was carried out by insufflation of talc via the trocar, with a pre-constructed kit without direct endoscopic vision (Steritalc®, Novatech, France), tilting the trocar and performing circular movements (Figs. 1 and 2). No tests were carried out to verify the presence of active air leaks during the endoscopic procedure. After MT, a large-bore drainage tube was inserted into the pleural cavity and anchored to the skin by a single stitch. After every procedure, the pleural cavity was placed under negative suction at − 20 cmH2O for at least 48 h to favor the visceral and parietal pleura apposition.

Fig. 1
figure 1

Insufflation of sterile talc for talc poudrage through the dedicated thoracic port

Full size image
Fig. 2
figure 2

Intrathoracic endoscopic view: results of the deposition of talc after insufflation

Full size image

When necessary, a few days after MT with TP, the instillation of intrapleural talc was repeated in slurry mode using a chest drain already in place by mixing sterile talc (Steritalc®, Novatech, France) in a suspension with 50 ml NaCl. After each slurry treatment, the drainage was clamped for 120–180 min and maintained under suction for 48 h. If clamping was not feasible because of the high airflow supply from the pleural cavity, the drain was positioned in a loop elevated above the patient’s level without suction for 120–180 min. At the end of this time interval, the drainage was put on suction again.

Postprocedural Assessment

Each patient was managed in an inpatient setting in a pulmonary unit at an academic hospital. The post-procedural observation in the endoscopic suite lasted 30–60 min, and a post-procedural chest X-ray was requested for each patient. All patients were subsequently monitored by thoracic ultrasound and chest X-ray during their hospitalization.

Review of Clinical Documentation

The medical records of patients were retrospectively reviewed via an electronic medical record by two different operators (AF and NC), and the following data were recorded: gender, age, smoking history, comorbidities, type and etiology of the PNX, PNX side, previous personal history of same side PNX, any previous treatments for PNX, date of radiological diagnosis, size of the PNX at diagnosis (width at the level of the hilum), chest computed tomography pattern, date of the procedure, days from the radiological diagnosis to the procedure, thoracoscopic appearance of the lung, endoscopic presence of pleural adhesions, thoracoscopic staging according to Vanderschueren [33], presence of pleural plaques, grams of talc used during talc poudrage, cumulative grams of talc instilled in the pleural cavity during hospitalization, size of the drain positioned at the end of the thoracoscopy, complications (bleeding, empyema, subcutaneous emphysema, drain dislocation, other), achievement of the primary endpoint (yes/no), need for additional procedures, length of time the chest drain remained in place, length of hospitalization, recurrence of PNX in the patient’s subsequent medical history, and date of eventual death.

Endpoints

The primary endpoint evaluated in the present study was the observation of complete radiographical lung re-expansion and absence of air supply from the chest drain within 7 days of MT. The primary endpoint was considered achieved even if the thoracic drainage remained in place longer than 7 days after MT, as long as the absence of air supply from the pleural cavity was well defined in the clinical documentation and a chest X-ray demonstrated complete lung expansion within the established time limit. The results obtained were then evaluated by studying the separate outcomes of the PSP and SSP subgroups.

The secondary endpoint evaluated was achieving no recurrence of ipsilateral PNX at 24 months post-discharge. The results and the primary endpoint were evaluated by studying the separate outcomes in the PSP and SSP subgroups.

Statistical Analyses

Data was expressed as numbers and percentages for categorical variables, while it was presented as median and interquartile range for quantitative variables. The Shapiro–Wilk test was used to analyze quantitative variables and determine whether they had a normal distribution. The association between categorical variables was examined using the chi-squared or Fisher exact tests, while quantitative variables were analyzed with Student’s t test or Mann–Whitney test as appropriate.

A logistic regression analysis was performed to identify the variables associated with a risk of non-resolving PNX at 7 days and a relapsing PNX within 24 months post-discharge. Unadjusted odds ratios (ORs) were computed to assess the strength of the association between physical variables and the predetermined endpoints. The OR estimates were calculated using 95% confidence intervals (CIs).

The cumulative incidence method was used to illustrate PNX recurrence, accounting for the presence of competing risks, such as mortality during the follow-up period.

The acceptable level of significance was defined as a p value < 0.05. Statistical analyses were performed using the Stata statistical software package (version 18.0; Stata Statistical Software: College Station, TX, USA).

Results

We enrolled 97 hospitalized patients with PNX between June 2008 to September 2021. After excluding patients because of missing data, we considered 95 patients (Fig. 3).

Fig. 3
figure 3

Recruitment diagram of the population considered. PSP primary spontaneous pneumothorax, SSP secondary spontaneous pneumothorax

Full size image

The median of patients age was 63.42 years (interquartile range, IQR 45), and 73 (76.84%) patients were men (see Supplementary file). Patients with SSP were significantly older than those with PSP (respective median age 73.07 vs. 23.69 years; p < 0.001) (see Supplementary file). Most patients (76/95, 80%) were current or former smokers. The majority of the cohort was made up of cases of PSP (32.63%) and SSP (63.16%), with a minority of cases of iatrogenic and traumatic PNX (3.15% and 1.05%, respectively). The etiologies of SSPs were COPD/emphysema (66.67%), interstitial lung disease (ILD) (21.67%), malignancy (5.00%), and acute infection (5.00%) (Table 1).

Table 1 Characteristics of the PNX in the recruited population
Full size table

The PNX cases were equally divided between the left and right hemithorax, with a median size of 50 mm. Overall 30.52% of patients had had at least one ipsilateral PNX before the episode evaluated by this study. Patients with PSP had a previous history of ipsilateral PNX in a more significant percentage of cases than SSPs (54.84% vs. 16.67%; p = 0.003). The median size of the PNX was larger for SSPs than PSPs (52.00 vs. 45.00 mm), but there was no statistically significant difference (p = 0.868). A trend was found in deferring MT for a slightly longer median time interval in cases of SSP compared to PSP (5 days vs. 4 days), although this was not statistically significant (p = 0.481). SSPs had a more pathological lung conformation on endoscopic evaluation compared to PSPs, demonstrating multiple blebs or multiple bullae more frequently (58.33% vs. 29.02%) and more frequently manifesting as grade III or IV Vanderschueren staging (60.00% vs. 32.25%). The SSP group had a higher prevalence of pleural adhesions on endoscopic evaluation (40.00% vs. 32.26%; p = 0.012). There was no difference in the presence or absence of pleural plaques at endoscopic evaluation between SSPs and PSPs (16.67% vs. 6.45%; p = 0.172). Median talc dosage administration during MT and hospitalization was not different between SSPs and PSPs. A trend was found in the positioning of larger caliber drains at the end of MTs performed for SSP compared to a PSP; however, no statistically significant difference was detected (p = 0.152) (see Supplementary file). Complications occurred in both SSPs (subcutaneous emphysema 15/60, 25.00%; empyema 2/60, 3.33%; drainage dislocation 1/60, 1.67%) and cases of iatrogenic PNX (subcutaneous emphysema 2/3, 66.67%; drainage dislocation 1/3, 33.3%), and in no case of PSP and post-traumatic PNX (See Supplementary file). No cases of bleeding were reported in the procedures investigated in the present study.

A subgroup (17/95; 17.89%) of patients required an additional procedure to MT with TP alone, and only one patient with SSP required subsequent surgery. The need for further interventions was more significant in the SSP group (15/60; 25.00%) than in all the other groups: PSP (2/31; 6.45%), iatrogenic (0/3; 0.00%) and post-traumatic (0/1; 0.00%) (Table 2).

Table 2 Hospitalization and follow-up details for the cumulative population
Full size table

The median time from placement of the chest drain at the end of MT to its removal was longer in SSPs than in PSPs (7.0 vs 4.0 days; p < 0.001). Also, the median LOS was longer for SSPs when compared to PSPs (19.5 vs. 7.0 days; p < 0.001). Considering the entire recruited population, the median time with chest drain in situ was 5 days, while the average LOS was 13 days.

A recurrence of PNX occurred on the same side within 24 months of discharge in 9.47% of patients, while 12.63% of patients had a recurrence of PNX during the entire observation period of the cohort (Fig. 4).

Fig. 4
figure 4

Cumulative incidence: survival (months) and probability of pneumothorax recurrence over the entire time interval considered in the follow-up of the cohort. PSP primary spontaneous pneumothorax, SSP secondary spontaneous pneumothorax

Full size image

Primary Endpoint

The primary endpoint, characterized by the achievement of lung expansion demonstrated radiographically in the absence of air leaks from the chest drain within 7 days of MT, was achieved by 74 patients (77.89% of the recruited population). The PSP group was statistically significantly more likely to achieve the primary endpoint than the SSP group (OR 0.25; CI [0.07–0.93]; p = 0.038) (Table 3).

Table 3 Endpoint details for PSP and SSP groups
Full size table

A variable significantly associated with reaching the primary endpoint was the pleural morphology visualized during MT: patients with a normal morphology or normal with anthracosis reached the primary endpoint in 89.96% of cases, while patients with blebs or bullae reached it in 69.39% of cases (OR 0.34; CI [0.19–0.97]; p = 0.004) (see Supplementary file). Receiving a cumulative dose of talc greater than or equal to 4 g during hospitalization was associated with a lower risk of meeting the primary endpoint (OR 0.14; CI [0.05–0.40]; p < 0.001).

Secondary Endpoint

The secondary endpoint, defined as the absence of recurrence of ipsilateral PNX 24 months after discharge, was achieved by 86 patients (90.52% of the recruited population). No statistically significant difference was found in the achievement of the secondary endpoint between PSP and SSP cases.

Contrary to what was observed for the primary endpoint, receiving a cumulative dose of talc greater than or equal to 4 g during hospitalization in all cases led to achieving the secondary endpoint, which occurred only in 89.23% of patients treated with less than 4 g. All the patients managed with a chest drain smaller than 28Fr met the secondary endpoint.

Discussion

The cohort recruited here predominantly comprised male patients and current or former smokers, the epidemiological groups most associated with spontaneous PNX [13, 34].

The finding of a more significant proportion of patients with previous episodes of PNX in the PSP group compared to the SSP one is dictated by the fact that, according to the protocol of the institution hosting the study and the considered guidelines during the study execution interval [35, 36], the first case of PSP detected at the institution is managed conservatively with observation only or subjected to either aspiration or drainage placement without carrying out procedures aimed at obtaining pleurodesis. Conversely, subsequent relapses of PSP, according to the local protocol, may be subject to surgical therapy or MT with TP on the basis of the specific case, often being discussed at a multidisciplinary group level with the thoracic surgical team. On the contrary, all SSP cases were candidates for invasive treatment after the first episode of PNX was detected; for this reason, most SSP cases recruited were managed with MT and TP during their first recorded episode.

The times from hospitalization to MT were not significantly different for the SSP group compared to the PSP one. However, in our clinical practice, it is usually preferred to wait a longer time interval in SSP in order to check for spontaneous resolution or the results of an initial minimally invasive treatment, such as percutaneous chest drainage with or without talc slurry or blood patch, which if proved unsuccessful is then followed by MT with TP. We report that intrapleural treatments performed prior to MT with TP were not recorded in the current study.

Both endoscopically assessed lung macroscopic morphology and Vanderschueren classification were significantly worse in grade in SSPs than in PSPs. This is justifiable since SSP foresees by definition the presence of a lung pathology at the basis of its etiology; in addition, patients with SSP, being older, have an aged lung, frequently exposed to chronic damage from smoking, environmental and work exposures [16, 17, 37, 38].

No significant difference was demonstrated between PSPs and SSPs in the grams of talc used during MT and throughout the hospital stay. This finding is probably due to the limited sample size. Of the patients undergoing further treatment and requiring additional instillation of talc, the majority were affected by SSP. Of the patients undergoing additional talc treatments, 12 received a talc slurry through the drainage positioned at the end of MT (10 cases of SSP and 2 cases of PSP), while 2 had a repeated MT with TP (2 cases of SSP).

The size of the chest drain positioned at the end of the procedure did not appear to be different on the basis of the type of PNX. At our institution there is no protocol for choosing the drainage lumen used at the end of the procedure, which is left as a choice to the operator who carries out the MT. Typically, we try to avoid drains with a lumen smaller than 24Fr. Generally, the operator is led to choose a larger-bore drain the greater the predictable airflow from the pleural cavity so as to avoid the development of subcutaneous emphysema [39].

The complications encountered occurred only in cases of PSP, SSP, and iatrogenic PNX. Of the 17 cases of subcutaneous emphysema identified, 16 were associated with SSP and 1 with a post-transbronchial biopsy iatrogenic PNX in an elderly patient with extensive lung emphysema. This finding is compatible with a greater degree of lung injury at the level of the visceral pleura, which leads to a high flow of air in the pleural cavity and the subcutaneous tissue layers [40, 41]. Cases of empyema occurred only in SSPs. A plausible reason is that these patients are fragile and suffer from many comorbidities, as well as frequently needing to keep the chest drain in place for prolonged periods, as demonstrated in the present study, favoring the development of pleural cavity infections [42]. Drain dislocation occurred in two cases of SSP and one iatrogenic PNX; the rate detected is low as all patients were hospitalized and managed in a highly specialized inpatient area with prolonged experience in managing pleural diseases and chest devices [43]. No patient demonstrated significant bleeding or died during the hospitalization investigated by this study.

Most patients (82.20%) did not require further procedures after MT with TP. Only one patient, aged 67, with sufficient performance status, underwent thoracic surgery after failure of MT with TP. This detail is an index of the effectiveness of MT with TP, which avoids the need for surgery in a significant proportion of cases, and of the frailty of patients affected by PNX, especially in cases of SSP, who are often poor candidates for general anesthesia. In fact, they frequently have considerably reduced lung function and comorbidities, often limiting their treatment alternatives [44,45,46].

Two patients required additional treatments without talc instillation: one required the placement of an additional chest drain to empty a large pocket of residual intrapleural air, while the other required the maintenance of a Heimlich valve as, after MT with TP was not effective, it was decided to opt for transfer to hospice care to start palliative measures.

Patients affected by PSPs reached the primary endpoint in a more significant proportion than SSPs, achieving lung re-expansion and closure of the air leak within 7 days of MT in 90.33% of cases; on the contrary, only 70% of SSPs achieved the objective. All considered cases of iatrogenic and traumatic PNX met the primary endpoint. This result is justified by a more compromised lung structure in patients with SSP. In the present study, visibly appreciable blebs or bullae during MT were associated with a greater risk of not reaching the primary endpoint. In addition, it is appropriate to observe that the majority of PSPs’ air leaks managed here would have predictably resolved in the interval time considered by the primary endpoint even with chest drainage alone; however, the treatment with MT and TP in these cases was aimed at obtaining a reduction in the rate of future recurrence of PNX.

On the contrary, in cases of SSP, the treatment with MT and TP had both an acute therapeutic purpose in causing inflammation at the level of the visceral pleura aimed at inducing the closure of the pleural breaches and a long-term prevention purpose in reducing the recurrence rate of PNX by generating adhesions between the parietal and visceral pleura. A significant finding was that the intrapleural administration of an amount equal to or greater than 4 g of talc during the hospitalization was associated with a greater risk of not reaching the primary endpoint. This data must be considered in light of which types of patients received additional doses of talc by repeating MT or receiving talc slurry, 12 of which were cases of SSP and 2 of PSP. These patients had air leaks that lasted for more extended periods and therefore needed to repeat the talc treatment, hence the greater risk of not reaching the conclusion of the air leaks within 7 days of drain placement.

No difference between PSPs and SSPs was found regarding the achievement of the secondary endpoint defined by the absence of recurrence of PNX 24 months after discharge. Patients with PSPs had a relapse in the time interval considered by the endpoint in 9.67% of cases, while SSPs in 10.00% of cases. Three additional patients with SSP had a recurrence after the end of the time interval considered by the secondary endpoint, until the end of the observation time of the cohort. All cases of iatrogenic and traumatic PNX reached the secondary endpoint and had no subsequent relapses. Considering all the etiologies of PNX included in the study, the recurrence rate was 9.47% at 24 months after discharge. This finding supports the efficacy of MT with TP regardless of the etiology of the treated PNX in selected patients. The intrapleural administration of an amount equal to or greater than 4 g of talc during the hospitalization resulted in the achievement of the secondary endpoint in all cases. This data must be interpreted as a possible chronic effect of the high dose of talc administered, which creates a greater share of pleural adhesions that prevent the detachment of the visceral and the parietal pleura. The finding that all patients managed with a chest drain smaller than 28Fr reached the secondary endpoint is justifiable by the presence of a less severe form of PNX in patients in this specific group.

Our therapeutic results for SSP appear to align with the scientific literature. A case series by Lee et al. indicated that over a 3-year follow-up, TP in SSP due to COPD had a 95% success rate; their analysis included four fatalities (9.8%) that were recorded within 30 days of therapy [11]. These outcomes are consistent with those in a case series reported by Tschopp et al., who found that 95% of cases treated with TP for persistent air leak or PNX recurrence did not relapse over a 5-year follow-up [47]. The results we obtained for PSP also align with the pertaining literature. Tschopp et al. conducted a randomized trial in the setting of PSP, comparing conservative treatment against intercostal tube drainage without intrapleural treatment vs. MT with TP for the initial treatment of PSP and found that TP was superior in preventing recurrence at 5 years (34% vs. 5% relapse rate), also increasing cost-effectiveness [9]. However, usually pleurodesis is not carried out in the first PSP episode and the current guidelines recommend preferring more conservative therapies such as observation, needle aspiration, or the placement of an ambulatory device [48]. Even though the least expensive PSP treatments include aspiration, monitoring, or chest drain placement [49,50,51], a surgical approach to patients during the initial episode of PSP appears to ensure a lower recurrence rate than that of less invasive treatments, as various systematic studies have demonstrated [49,50,51]. It is unknown, though, which patients have a greater recurrence rate following the initial PSP episode and have to be considered right away for a more invasive intervention [52]. In addition, notwithstanding the initial available evidence supporting MT in the therapeutic setting of PSP, the guidelines currently recommend VATS or thoracotomy as treatments for recurrent PSP [48].

It is debatable whether the use of MT is preferential to that of uniportal VATS without intubation. This surgical procedure to date performed only in centers of excellence and high specialization has clinical indications whose margins are blurred compared with MT and greater procedural tolerance when compared to traditional VATS even by the frail patient [53,54,55].

The procedural workflow described in the current article is considered the standard of care for MT in the literature pertinent to interventional pulmonology [3].

We are not aware of any studies that have subjected patients with iatrogenic or traumatic PNX to MT with TP, and in our analysis, although there were few cases, the observed results were excellent. This outcome can certainly be interpreted as a selection bias on the operator’s part, who may have selected less severe PNX cases with a greater probability of resolution associated with the procedure.

The retrospective nature of this study, focused on recruiting patients undergoing a specific interventional procedure, presents several inherent limitations that warrant careful consideration. First and foremost, retrospective studies rely on existing medical records, potentially leading to incomplete or missing data. As far as this study is concerned, within the variables considered, only two patients were excluded as a result of missing data. Additionally, the lack of a control population and the potential for confounding variables pose challenges in establishing causal relationships between variables. The study’s retrospective design limits the ability to implement randomization, impacting the establishment of a cause-and-effect relationship and making it challenging to account for potential sources of bias. The outcomes observed in the study can certainly be interpreted as a selection bias on the operator’s part, who may have selected less severe PNX cases with a greater probability of resolution associated with the procedure. In addition, the absence of an evaluation and comparison of the hospitalization period prior to MT with TP, where different intrapleural treatments may have been carried out between the various patients, represents a limitation of the study. Furthermore, the generalizability of the findings may be compromised, as the study population may not be representative of the broader population undergoing similar procedures. In summary, while this retrospective study offers valuable insights into a real-world clinical scenario, readers must be cautious in interpreting its results because of the inherent limitations associated with its design.

Conclusions

Our study supports prior evidence showing a high level of safety and efficacy of MT in treating PNX both in the short and long term. Future prospective and preferentially randomized clinical trials will serve to determine which PNX phenotype corresponds to the best prognostic outcome secondary to MT treatment with TP and which types of pathologies are best treated with other procedures. In addition, the cost-effectiveness of MT with TP in the various types of PNX is poorly addressed in the literature and also deserves adequately designed prospective studies.

MT as a therapeutic alternative must not aim to replace the surgical options for the pathological entities considered in this document but must find its role as a low-cost, safe, and highly effective therapeutic choice in the hands of the interventional pulmonologist.

In order to reduce the risk of recurrence of PNX, minimize healthcare costs, LOS, and morbidity, patients affected by this clinical entity must be promptly cared for by personnel expert in the management of PNX once it has been identified.