Outcome of medical thoracoscopy in patients admitted to abbasia chest hospital

Results A total of 123 patients were available for analysis. Their mean age was 58.63 (22–80) years, and 64 (52%) were male. The mean duration of chest drain after procedure was 9.79 (3–41) days, and the duration of hospital stay was 24.54 (10–55) days. Malignant histology was reported in 108 (87.8%) patients, with 75 (61%) cases of mesothelioma. In 108 (87.8%) patients, pleurodesis was performed. The incidence of complications among the patients was 12.2% of all patients. The most common complications were blocked drain and empyema; other complications included subcutaneous emphysema, drain dislodgement,


Introduction
Thoracoscopy was introduced more than 100 years ago by Hans-Christian Jacobaeus from Sweden and has become today the second most important endoscopic technique in respiratory medicine after bronchoscopy [1]. Inclusion criteria were as follows: (a) patients were eligible when they presented with exudative pleural effusion and had thoracocentesis as a nonconclusive diagnostic procedure and (b) patients should be able to give informed written consent. Exclusion criteria were as follows: (a) general contraindications to thoracoscopy, (b) lack of a pleural space owing to pleural adhesions, (c) inability to lay supine, (d) inability to tolerate a pneumothorax, (e) severe cardiac disease, (f) severe respiratory disease unrelated to the effusion, (g) severe coagulopathy (i.e. platelet count <60 000 and the international normalized ratio <1.2.), (h) uncontrolled cough, and (i) hypoxemia not owing to pleural effusions [2]. Medical thoracoscopy involves passage of an endoscope through the chest wall and offers the clinician an access for direct visualization and taking pleural biopsies. It is a valuable diagnostic procedure, and in some cases, it can also be a therapeutic procedure [3]. Medical thoracoscopy is a relatively safe procedure with an extremely low mortality rate [4]. Indications of medical thoracoscopy include workup and diagnosis of idiopathic pleural effusions, staging of lung cancer, staging for malignant pleural mesothelioma (MPM), site-directed biopsy of parietal pleura, and pleurodesis [5]. Major contraindications to thoracoscopy include the lack of a pleural space owing to pleural adhesions, inability to lay supine, inability to tolerate a pneumothorax, severe cardiac disease, severe respiratory disease unrelated to the effusion, and severe coagulopathy. Relative contraindications are uncontrolled cough and refractory hypoxemia that is not owing to pleural effusions [2].

Patients and methods
We performed a retrospective analysis of patients who underwent thoracoscopy for unexplained exudative pleural effusion at Abbassia Chest Hospital over a 12-month period (from October 2015 to September 2016).
Demographic details, procedure date, and histology reports were recorded from the procedure record book in our dedicated thoracoscopy room. Admission and discharge dates and date of death (if happened) were obtained from the hospital's patient administration system database.
Thoracoscopy was done using a thoracoscope, Richard wolf rigid thoracoscope (Germany). By the single entry technique under local anesthesia, followed by drainage of fluid present in the pleural space, and then induction of an ipsilateral pneumothorax to allow good visual exposure, suspicious areas instead of abnormal areas. Biopsies were collected in formalin solution for histopathological examination. Finally, at the end of the procedure, an intercostal tube under water seal was then inserted before wound closure to evacuate air and residual fluid. Chest tubes were removed when the amount of drained pleural fluid became less than 100 ml daily. Chemical pleurodesis was done for proved malignant cases.
Data were coded and entered using the statistical package SPSS (statistical package for the social sciences; SPSS Inc., Chicago, Illinois, USA) version 24. Data were summarized using mean, standard deviation, median, minimum, and maximum in quantitative data and using frequency (count) and relative frequency (percentage) for categorical data. Comparisons between quantitative variables were done using the nonparametric Mann-Whitney test [6]. For comparing categorical data, χ 2 -test was performed. Exact test was used instead when the expected frequency is less than 5 [7]. Correlations between quantitative variables were done using Spearman's correlation coefficient [8]. P values less than 0.05 were considered as statistically significant. P values equal or less than 0.001 were considered as highly significant. P values equal or more than 0.05 were considered as statistically insignificant.
The mean duration of hospital stay was 24.54±8.46 days, and the mean duration of post-thoracoscopic drainage with intercostal chest tube was 9.79±5.65 days.
A total of 108 (87.8%) patients were diagnosed as having malignant pleural effusion, whereas 15 (12.19%) patients were diagnosed as having nonmalignant. The most common diagnosis was malignant mesothelioma in 75 (61%) cases followed by mesothelioma versus metastatic carcinoma in 22 (17.9%) cases. The least common diagnosis was tuberculous effusion in seven (5.7%) patients. The most common cytology finding was epithelioid cells in 70 (56.91%) cases, followed by mesothelial cells and lymphocytes in 12 (9.75%) cases, and the least common cytology finding was multicystic cells in one case.
Of 123 patients, 15 (12.2%) had complications. The most common complications were blocked drain and empyema; other complications included subcutaneous emphysema, drain dislodgement, and bronchopleural fistula, and the least common complications are respiratory failure and atrial fibrillation ( Table 1).
In 93.49% (n=115) of the patients, a specific diagnosis was established. In 87.8% (n=108), pleurodesis was performed. Overall, 85.36% (n=105) were referred for oncotherapy, and 2.4% (n=3) of the patients died before referral to oncotherapy (mortality was owing to the main disease and not related to the procedure itself). in 5.7% (n=7), antituberculous treatment was given, and 2.4% (n=3) of the patients died. The indication for pleurodesis was malignant pleural exudate with subsequent need for thoracocentesis.
There were significant differences between patients with malignant and those with nonmalignant effusion regarding age. There were insignificant differences between patients with malignant and those with nonmalignant effusion regarding sex. There was a significant statistical difference between patients with malignant and those with nonmalignant effusion regarding age and living in Cairo (Table 2).
A positive correlation was found between duration of hospital stay and age.
There was a significant relation between complications and duration of drainage of intercostal tube (ICT). As  (Table 3).
Moreover, a significant relation between mortality and duration of ICT drainage was found. Mean duration of ICT drainage in the dead patients was 28.67±12.50 days, whereas in the rest of the patients, it was 9.15 ±4.68 days (Table 4).
There was no significant relation between diagnosis and complications (Table 5).
There was no significant relation between diagnosis and mortality (Table 6).
There was a highly significant statistical relation between malignant pleural effusion and residence in Helwan, Qaliobia, and other cities rather than Cairo. However, there is a significant statistical relation between malignant pleural effusion and residence in Cairo (Table 7).

Discussion
Medical thoracoscopy is a valuable diagnostic procedure and, in some cases, can also be a therapeutic procedure. It involves passage of an endoscope through the chest wall and offers the clinician an access for direct visualization and taking pleural biopsies [3].
This study is a retrospective study of the outcome of medical thoracoscopy in Abbassia Chest Hospital retrospectively from October 2015 to September 2016.
The present study included 123 patients, and all of them had pleural effusion that has not been finally diagnosed after history, general and local examination, and investigations including thoracocentesis with physical, chemical, bacteriological, and cytological examination of the pleural fluid.
Of the studied 123 patients, 59 (48.0%) were females and 64 (52.0%) were males; the age of patients in the  Regarding residence, in the current study, there was a highly significant statistical relation between malignant pleural effusion and residence in Helwan, Qaliobia and other cities rather than Cairo. However, there is a significant statistical relation between malignant pleural effusion and residence in Cairo. This result does not match with Mabrouk et al. [9], who studied 103 cases of pleural effusion at Abbassia Chest hospital and found a significant association between malignant effusion and living in Helwan only. This also does not match with Madkour et al. [11], who studied 3892 cases, where 2913 of them were environmentally exposed to asbestos and a control group of 979 with no history of exposure; they found that there is exposure response relationship between asbestos and MPM. This was an epidemiological and environmental study that was carried out in Shubra El-Kheima City, Greater Cairo. The unmatching may be owing to increased industrial regions and increased pollution rate in all cities of Egypt.
In the current study, the mortality ratio is 2.4% (mortality was owing to the main disease and not related to the procedure itself); the incidence of complications between the patients was 12.2%. The most common complications were blocked drain (4.06%) and empyema (3.25%); other complications included subcutaneous emphysema (2.44%), drain dislodgement (1.63%) and bronchopleural fistula (1.63%), and the least common complications are respiratory failure (0.8%) and atrial fibrillation (0.8%). This does not match with the results obtained by Michaud et al. [2]. Their study was conducted on 50 patients with unexplained pleural effusion referred for medical thoracoscopy at Abbassia Chest Hospital, and they showed that 10% had minor complications: 4% had infection (cellulitis) at the drain site, 4% had surgical emphysema, and 2% had bronchopleural fistula. This also does not match with results of Ahmed et al. [12]. Their study was carried out at the chest department of Zagazig University Hospitals in the period from October 2014 to October 2015. It included 36 patients with undiagnosed pleural effusion. They showed that postthoracoscopic complications in their studied groups were surgical emphysema and prolonged air leak in three (8.3%) patients, pain during procedure in two (5.6%) patients, wound infection in two (5.6%) patients, and dislodged tube in two (5.6%) patients (high incidence of surgical emphysema and prolonged air leak  [12]. Their study was carried out at the Chest Department of Zagazig University Hospitals in the period from October 2014 to October 2015. It included 36 patients with undiagnosed pleural effusion, and they showed the following: the histopathological yield of thoracoscopic pleural biopsies was as follows: 25 (69.4%) malignant cases, two (5.6%) patients with tuberculous pleuritis, one (2.8%) patient diagnosed with empyema, and another one (2.8%) with rheumatoid arthritis; moreover, there were seven (19.4%) patients with nonspecific inflammation. Study limitations in this research include missing detailed data about the sclerosing material and its success rate, and also the cause of death in patients with malignant pleural effusion, and this is may be contributed to being a retrospective study.

Conclusion
Medical thoracoscopy is a minimally invasive procedure that allows visualization of the pleural space and intrathoracic structures. Medical thoracoscopy enables taking pleural biopsies under direct vision and performing therapeutic drainage of pleural effusion. Persistent and recurrent exudative pleural effusions become common, and thoracocentesis does not give a definitive diagnosis in many patients. Therefore, thoracoscopy today remains the gold standard for these cases.