{'fraction_non_alphanumeric': 0.027449005288340468, 'fraction_numerical': 0.01592797783933518, 'mean_word_length': 5.483673469387755, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Therapeutic rigid bronchoscopy at a tertiary care center in North India: Initial experience and systematic review of Indian literature

we report our initial 1‑year experience with this procedure. Materials and Methods: A prospective observational study on the indications, outcomes, and safety of various rigid bronchoscopy procedures performed between November 2009 and October 2010. Improvement in dyspnea, cough, and the overall quality of life was recorded on a visual analog scale from 0 to 100 mm. A systematic review of PubMed was performed to identify studies reporting the use of rigid bronchoscopy from India. Results: Thirty‑eight rigid bronchoscopies (50 procedures) were performed in 19 patients during the study period. The commonest indication was benign tracheal stenosis followed by central airway tumor, and the procedures performed were rigid bronchoplasty, tumor debulking, and stent placement. The median procedure duration was 45 (range, 30‑65) min. There was significant improvement in quality of life associated with therapeutic rigid bronchoscopy. Minor procedural complications were encountered in 18 bronchoscopies, and there was no procedural mortality. The systematic review identified 15 studies, all on the role of rigid bronchoscopy in foreign body removal. Conclusions: Rigid bronchoscopy is a safe and effective modality for treatment of a variety of tracheobronchial disorders. There is a dire need of rigid bronchoscopy training at teaching hospitals in India. ABSTRACT


INTRODUCTION
Rigid bronchoscopy is the transoral (or trans-tracheotomy) passage of rigid instruments for diagnostic or therapeutic purposes in the tracheobronchial tree. It was reported in the 19 th century by Gustav Killian, and remained the only method for diagnostic and therapeutic procedures in the airways for a significant period. [1] The practice of rigid bronchoscopy greatly decreased following the invention of bronchoscope can be passed through the barrel of the rigid bronchoscope and removes the restriction of visualization of the upper lobes and peripheral lesions. [6] Ideally, an interventional pulmonologist should be well versed with both rigid and flexible instruments while performing therapeutic bronchoscopic interventions.
We started therapeutic rigid bronchoscopy in 2009, and herein we report our initial 1-year experience with this procedure.

MATERIALS AND METHODS
This was a prospective observational study conducted at the Department of Pulmonary Medicine at Postgraduate Institute of Medical Education and Research, Chandigarh, between November 2009 and October 2010. The primary objective of the study was to observe the indications, outcomes, and safety of various rigid bronchoscopy procedures. The study population included all consecutive patients undergoing the rigid bronchoscopy procedure during the study period. The study protocol was approved by the Ethics Review Committee, PGIMER, Chandigarh, and a written informed consent was obtained from all patients (or next of the kin) prior to the procedure. All the patients had their history reviewed and underwent relevant physical examination prior to procedure. Preprocedure assessment included performance of complete blood count, coagulation profile, urea, and electrolytes.

Instruments for rigid bronchoscopy
Rigid tracheoscope and tracheobronchoscopes (Karl Storz, Germany) of lengths 33 cm and 43 cm, respectively, of varying internal diameters (3.5-14 mm) with proximally inserted prismatic light deflectors were used. Optical images were obtained using a Hopkins Straight Forward Telescope (with fiberoptic light system incorporated) of 2.9 mm diameter and 50 cm length. TONN stent applicator system (for stent with OD 14-18 mm and maximum 10 cm length) was employed for silicon stent deployment. Balloon dilatation was performed using controlled radial expansion (CRE) balloons (Boston Scientific, USA).

Anesthesia for rigid bronchoscopy
Rigid bronchoscopy was performed using total intravenous anesthesia. Patients were kept fasting for at least 6 h (2-3 h in emergency situations) prior to the procedure. All procedures were performed in the operating suite, where facilities of a trained anesthesia team were readily available. Induction was performed with propofol and fentanyl. Subsequently, suxamethonium was administered and rigid bronchoscopic intubation was carried out. Anesthesia was maintained with propofol infusion and muscle relaxation by suxamethonium or atracurium as intermittent boluses. At the end of the procedure, reversal of anesthesia was achieved with neostigmine and glycopyrrolate. Indications for continuing postprocedure ventilatory support were individualized according to patient's clinical condition, duration of procedure, and degree of laryngeal manipulation. In patients with critical narrowing of the airway lumen, only deep sedation was initially employed. Neuromuscular blockers were administered only once the airway was secured after negotiating the rigid bronchoscope across the obstructed airway.

Rigid bronchoscopic procedures
Rigid bronchoscopic intubation was performed according to the standard technique. [6] Once the trachea was intubated, the anesthetist ventilated the patient through the ventilating channel of the bronchoscope. The scope was further advanced into the trachea for visualization. Tracheal dilatation was performed by gentle corkscrewing motion of the barrel across the stenosed segments. Occasionally, CRE balloons were initially employed followed by passage of the rigid barrel. Luminal patency in central airway tumor was accomplished by mechanical debulking using the bevel of the rigid bronchoscope. [7] In all these procedures, care was taken to maintain the rigid barrel parallel to the tracheobronchial axis.

Outcomes
We recorded the time taken for the procedure, time to recovery from anesthesia, time to extubation, and procedural complications. Improvement in dyspnea, cough, and the overall quality of life was recorded on a visual analog scale (VAS) from 0 to 100 mm (0 = no improvement; 100 = complete relief). Routine radiological investigations and/or flexible bronchoscopy were performed to assess improvement in nature of lesion. Data are presented in a descriptive fashion using mean (standard deviation [SD]). The improvement in the pre-and post-procedure VAS was analyzed using the Wilcoxon signed-rank (matched pairs) test.

Systematic review
A systematic review of the PubMed database (1965 to April 2012) was performed using the following the search terms: (Rigid bronchoscopy OR rigid bronchoscope OR rigid tracheoscopy) AND (India OR Indian). We excluded case reports and series with <10 patients.

RESULTS
During the study period, 38 rigid bronchoscopies were performed on 19 patients. The median number of rigid bronchoscopies performed per patient was two (range, one to six). In 30 (79%) procedures, flexible bronchoscopy was performed for assessment prior to rigid bronchoscopy. The indications for rigid bronchoscopy are summarized in Table 1. The most common indication was benign tracheal stenosis followed by CAO due to tumors. Fifty procedures were performed during 38 interventions [ Table 2]. Tracheal silicon and Montgomery T-tube stent placement was performed in five and two patients, respectively, with postintubation tracheal stenosis. In two patients with lung cancer and CAO, a silicone Y-stent was inserted [ Figures 1-3]. The other procedures performed included suctioning of endobronchial mucus plugs (one patient), stent repositioning (three patients), stent removal (three patients), suction, and tamponade along with endobronchial adrenaline instillation (one patient), right main bronchus balloon dilatation (one patient), and mitomycin C application over tracheal stenosis postrigid bronchoplasty (one patient). Rigid bronchoscope alone was used in 22 interventions (57.9%) and in 16 (42.1%) interventions, flexible bronchoscope was passed through the rigid barrel. Minor complications were encountered in 18 interventions [ Table 3]; there was no procedural mortality.
The mean (SD) duration of the procedure was 66 (29) min. Twenty-five instances (65.8%) required assisted mechanical ventilation following the procedure. The median time to extubation was 8 h. The median time to discharge from the hospital following the procedure was 5 days (range, 1-22 days). Repeat interventions prior to discharge were carried out following the nine rigid bronchoscopies. Therapeutic bronchoscopy procedures were associated with a significant improvement in the quality of life scores as assessed by VAS [ Table 4].

Systematic review
Our search yielded 39 references and 15 references met our criteria for inclusion [ Table 5]; [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] the remaining were mainly case-reports or small case series. All the reports are those involving foreign body removal using the rigid bronchoscope, some reports are those of combined rigid and flexible bronchoscopy. [8,9,22] The majority are those from the domain of the otorhinolaryngologist, in fact only one report involved the pulmonary physician. [9] The complication rate is variable and mortality has also been reported [ Table 5]. There is no study reporting the use of rigid bronchoscopy for interventional pulmonology       Tracheotomy done in four patients and foreign body was removed through tracheostoma in one patient Singh et al. [14] 2009 Foreign body aspiration 342 children with foreign body obstruction RB Rigid bronchoscopy was successful in retrieving the foreign bodies in 338 (98.8%) cases Four (1.2%) cases required additional tracheostomy, either to protect the airway during the procedure or to assist in removing the foreign body.
No mortality or long-term complication because of the tracheostomies Shubha et al. [15] 2009 Foreign body aspiration in infants
The primary aim of the study was to compare indication and recovery characteristics of sevoflurane and halothane; M: F (32:12)

RB
The authors concluded that halothane is as suitable as sevoflurane for children undergoing RB but sevoflurane has an advantage of quicker recovery. Exact details of RB procedure outcome not described as the study was focussed on the anesthesia perspective Bradycardia and arrhythmias occurred in nine patients and desaturation (SpO 2 <93%) occurred in nine patients. No procedure-related mortality reported Shivakumar et al. [20] [21] 2003 To evaluate the merits and demerits of pediatric rigid bronchoscopy for foreign body removal with or without the use of Hopkins telescope 60 pediatric patients. 0-3 years of age (M: F 3:1). 30 underwent the telescopic and 30 underwent nontelescopic procedure RB Telescope provided better illumination, higher optical resolution, and magnification. Foreign body removal with telescope was completed with minimal complications (less foreign body drops and lesser grasping attempts) though the procedure took more time. Patients in the telescope group had shorter duration of hospital stay The major complications encountered in the nontelescopic group were pneumothorax 2 (6.7%) and further impaction of the foreign body in 3 (10%).
In the telescopic category, further impaction of the foreign body owing to the accidental pushing down of the object during the procedure was recorded in 3 (10%). Other minor complications were controllable bleeding and minor mucosal abrasions Kapoor [22] 1982

DISCUSSION
This study was conducted in the setting of one of the largest tertiary care teaching institutes of North India. During the study duration, the majority of the therapeutic bronchoscopy procedures were performed using the rigid bronchoscope. In 80% cases, the therapeutic rigid bronchoscopic intervention was performed for the management of CAO. In India, the most commonly reported use of rigid bronchoscopy is for foreign body removal. In fact, our systematic review did not identify any study reporting the use of rigid bronchoscopy for interventional pulmonology procedures such as tumor debulking, stent placement, and others. At the time of initiation of the study, we had anticipated that most procedures would be performed for palliation in malignant tracheobronchial obstruction. In contrast to our expectation, the majority of these interventions were in benign conditions (77.2%) with a therapeutic rather than palliative intent.
Bronchoplasty in cases of benign tracheal stenosis was performed with the barrel of the rigid scope by sequential dilatation and occasionally using the CRE balloon. Dilatation was followed by silicon stent placement in seven cases of tracheal stenosis. There was dramatic symptom relief in all these cases as has been well highlighted in the literature. [6,[23][24][25] All our patients with tracheal stenosis had circumferential strictures that have been shown to be associated with poorer outcomes. They also require more aggressive intervention than the eccentric strictures. [26] This was apparent by the repeated requirement of rigid bronchoscopic dilatations and repeated restenosis. Mitomycin C application was applied after rigid bronchoscopic dilatation of tracheal stenosis in one patient, but its use in benign tracheal stenosis is a controversial topic. [27] The definitive treatment of benign tracheal stenosis remains tracheal reconstruction surgery. [28] However, surgery could not be performed in our patients both because of lack of surgical expertise and unwillingness of the patients. Five rigid bronchoscopy procedures were performed for foreign body removal of which four were successful.
One patient had a long history of foreign body inhalation with excessive granulation tissue covering the foreign body. In one patient, rigid bronchoscopy was used successfully for the management of massive hemoptysis, where it is the method of choice due to its better suction ability. [29] Previously, external beam radiation was considered the treatment of choice for patients with CAO. If interventional pulmonology services are available, endoscopic interventions should be strongly considered as the first line of management of CAO as the results of external beam radiation are delayed and often unpredictable. Rigid bronchoscopy allows immediate results and has a favorable safety profile. [30] Although tumor excision has been performed using the flexible bronchoscope, [31] it can be most rapidly and safely accomplished through the rigid bronchoscope. [32] Radiation therapy can then consolidate the effect of endoscopic therapy, usually in patients whose performance status has been improved by a first-line bronchoscopic intervention.
Performance of therapeutic rigid bronchoscopy requires teamwork especially understanding between the interventionist and the anesthetist as they share the airway. At least three team members are required for quick and easy performance of the procedure. We had a primary assistant who stood beside the operator and was involved in cleaning the telescope tip in between the insertions and management of the equipment assembly and optics, suctioning and manipulation of the forceps, and the CRE balloon as and when required. The respiratory technician was present behind the operating team and was involved in the management and handing over the instruments to the operating team.
In conclusion, this study reports our initial experience with rigid bronchoscopy and highlights the advantage of this procedure. Currently, the flexible bronchoscope is being employed for the majority of the diagnostic and many therapeutic bronchoscopic procedures. This has led to decline in rigid bronchoscopy training, even at most teaching institutes. However, it is essential that the pulmonologists are familiar with rigid bronchoscopy as the rigid bronchoscope remains the "gold" standard technique for therapeutic airway procedures.