Long-Term Success of Metal Endobronchial Stents in Lung Transplant Recipients.

BACKGROUND: Bronchial stenosis is a common complication following lung transplantation. We evaluated long-term associations of the use of self-expandable metal stents (SEMSs) with lung function tests, patient safety, and survival. METHODS: A retrospective chart review of 582 lung transplantations performed at our institution between January 2002 and January 2018. Fifty-four patients with SEMSs (intervention group) were matched one-to-one to patients without SEMSs (control group) using propensity score matching for age, sex, the year, and type of transplantation (unilateral/bilateral), and underlying disease. Data regarding long-term lung function and survival were compared between the groups. RESULTS: During a median follow-up of 54.8 months, the difference in survival between the study groups was not statistically significant (p = 0.2). Following 5, 7.5 and 10 years, values of mean forced expiratory volume in 1 second (FEV1) were comparable between patients with and without SEMSs as follows: 59.5 versus 62.6% (p = 0.2), 55.9 versus 55.0% (p = 0.4), and 63.5 versus 61.9% (p = 0.3), respectively. In the intervention group, a significant increase in the mean FEV1 was observed in 60 days after stent insertion (from 41.9 ± 12.8 to 49.5 ± 16.7% days, p < 0.001). Long-term complications following stent insertion included severe bleeding (1.8%), stent fractures (7.4%), stent stenosis (7.4%), stent collapse (3.7%), endobronchial pressure ulcer (1.9%), and stent migration (1.9%). CONCLUSION: SEMS insertion is associated with a positive sustained effect on lung function, without increasing long-term mortality. Thus, airway stenosis after lung transplantation can be safely and successfully treated using endobronchial metal stenting, with tight bronchoscopic follow-up and maintenance.

Transbronchial Cryobiopsies for the Diagnosis of Diffuse Parenchymal Lung Diseases: Expert Statement from the Cryobiopsy Working Group on Safety and Utility and a Call for Standardization of the Procedure.

Transbronchial cryobiopsies (TBCB) have recently been introduced as a promising and safer alternative to surgical lung biopsy in the diagnostic approach to diffuse parenchymal lung diseases (DPLD). Despite a substantial and expanding body of literature, the technique has not yet been standardized and its place in the diagnostic algorithm of DPLD remains to be defined. In part, this reflects concerns over the diagnostic yield and safety of the procedure, together with the rapid spread of the technique without competency and safety standards; furthermore, there is a substantial procedural variability among centers and interventional pulmonologists. We report this expert statement proposed during the third international conference on "Transbronchial Cryobiopsy in Diffuse Parenchymal Lung Disease" (Ravenna, October 27-28, 2016), which formulates evidence- and expert-based suggestions on the indications, contraindications, patient selection, and procedural aspects of the procedure. The following 5 domains were reviewed: (1) what is the role of TBCB in the diagnostic evaluation of DPLD: patient selection; (2) pathological considerations; (3) contraindications and safety considerations; (4) how should TBCB be performed and in what procedural environment; and (5) who should perform TBCB. Finally, the existence of white paper recommendations may also reassure local hospital credentialing committees tasked with endorsing an adoption of the technique.

The diagnostic value of tissue button technique for specimen accusation during endobronchial ultrasound-guided transbronchial fine-needle aspiration.

INTRODUCTION: The quality of tissue acquisition during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a major determinant of the diagnostic yield of the procedure. In the tissue button (TB) technique, the retrieved cellular specimen is fixed in ethanol and subsequently scraped from slide using surgical blade into formaldehyde and processed like ordinary tissue biopsy thus potentially increasing its diagnostic value. OBJECTIVES: To retrospectively evaluate the diagnostic yield of a TB technique in patients undergoing EBUS-TBNA for various malignant and benign conditions. METHODS: The diagnostic yield of specimen obtained by two methods (TB and traditional cell-block technique) performed during the same procedure are outlined in 46 patients who underwent EBUS-TBNA (median age = 65, range 19-85 years). RESULTS: Overall, in both malignant and benign conditions, TB resulted in clear diagnostic material in 43/46 (93.4%) patients. Specifically, TB provided clear histological diagnosis of malignancy (either primary lung cancer or metastases from extra-thoracic cancer) in 30/46 (65.2%) patients and granulomatous inflammation in 11/46 (23.9%) of patients. Only in two patients TB did not provide diagnostic material. CONCLUSIONS: The newly introduced TB technique provides valuable histological diagnostic material during EBUS-TBNA both malignant and benign conditions. Given its simplicity and its high diagnostic yield, TB should be considered to be used as one of the preferred specimen acquisition modalities during EBUS-TBNA specimen processing. Direct comparison to alternative tissue processing techniques during EBUS-TBNA should be explored in further randomized prospective studies.

Prospective Randomized Trial Evaluating Ketamine for Adult Bronchoscopy.

BACKGROUND AND OBJECTIVES: Ketamine has been used in pediatric flexible fiberoptic bronchoscopy (FFB). Its efficacy and safety for sedation of adults undergoing FFB has not been thoroughly investigated, and, consequently, it is not used by most interventional bronchoscopists. We aimed to evaluate the safety and efficacy of sedation for FFB under ketamine-propofol-midazolam (KPM) compared with the fentanyl-propofol-midazolam (FPM) regimen. MATERIALS AND METHODS: This was a prospective randomized trial of adult patients (n=80) undergoing FFB, randomized to receive sedation with either KPM (n=39) or FPM (n=41). Vital signs including transcutaneous carbon dioxide tension (TcPCO2) were continuously monitored. Sedation-related complications and interventions to maintain respiratory and hemodynamic stability were compared. Both operator and patient were blinded to the sedation regimen used. The operator's and patient's satisfaction from sedation were assessed following recovery. RESULTS: Maximal intraprocedural TcPCO2 values and minimal oxygen saturation did not differ significantly between the KPM and FPM groups (63.2±11.4 mm Hg vs. 61.1±7.2 mm Hg) and (77.1%±12.5% vs. 81.8%±12.0%), respectively. No significant differences were noted between the KPM and FPM groups with respect to sedation-related respiratory or hemodynamic complications. The operator's and patient's satisfaction from sedation was similar between the groups. CONCLUSIONS: Ketamine is as safe and effective as fentanyl for adult analgesia and sedation during FFB. In light of this observation and the fact that ketamine does not cause hemodynamic suppression, like most sedative agents, and is a potent bronchodilator, should encourage its more widespread use for adult sedation during FFB.

Long-term Outcome of Short Metallic Stents for Lobar Airway Stenosis.

BACKGROUND: Whereas stents are considered an excellent treatment for proximal central major airway stenosis, the value of stenting for distal lobar airway stenosis is still controversial. Our aim was to explore the short-term and long-term outcome of metallic stents placed for benign and malignant lobar airway stenosis. METHODS: Between July 2007 and July 2014, 14 patients underwent small airway stent insertion. The clinical follow-up included serial semiannual physical examinations, pulmonary function tests, imaging, and bronchoscopy. RESULTS: The etiologies for airway stenosis were: early post-lung transplantation bronchial stenosis (N=5), sarcoidosis (N=1), amyloidosis (N=1), anthracofibrosis (N=1), right middle lobe syndrome due to external lymph node compression (N=1), lung cancer (N=4), and stenosis of the left upper lobe of unknown etiology (N=1). Stents were placed in the right upper lobe bronchus (N=2), right middle lobe bronchus (N=6), left upper lobe bronchus (N=4), linguar bronchus (N=1), and left lower lobe bronchus (N=1). The median follow-up period ranged from 2 to 72 months (median 18 mo). Immediate relief of symptoms was achieved in the vast majority of patients (13/14, 92%). Out of 10 patients with benign etiology for stenosis, 9 (90%) experienced sustained and progressive improvement in pulmonary function tests and clinical condition. CONCLUSIONS: We describe our positive experience with small stents for lobar airway stenosis; further prospective trials are required to evaluate the value of this novel modality of treatment.

Survival following lung transplantation for artificial stone silicosis relative to idiopathic pulmonary fibrosis.

BACKGROUND: Silicosis is a progressive lung disease resulting from the inhalation of respirable crystalline silica. Lung transplantation is the only treatment for end-stage silicosis. The aim of this study was to analyze the survival experience following lung transplantation among patients with silicosis. METHODS: We reviewed data for all patients who underwent lung transplantation for silicosis and a matched group undergoing lung transplantation for idiopathic pulmonary fibrosis (IPF) at a single medical center between March 2006 and the end of December 2013. Survival was followed through 2015. RESULTS: A total of 17 lung transplantations were performed for silicosis among 342 lung transplantations (4.9%) during the study period. We observed non-statistically significant survival advantage (hazard ratio 0.6; 95%CI 0.24-1.55) for those undergoing lung transplantation for silicosis relative to IPF patients undergoing lung transplantation during the same period. CONCLUSIONS: Within the limits of a small sample, survival in silicosis patients following lung transplantation was not reduced compared to IPF. Am. J. Ind. Med. 60:248-254, 2017. © 2017 Wiley Periodicals, Inc.

Bronchoscopic Drainage of Lung Abscesses Using a Pigtail Catheter.

BACKGROUND: Lung abscesses are commonly treated with antibiotics. However, some patients fail to respond and may require percutaneous catheter drainage or surgical intervention. Bronchoscopic drainage (BD) of lung abscesses emerged as a therapeutic alternative in selected patients. OBJECTIVE: To describe our experience with 15 patients who underwent BD at our center during 2006-2016. METHODS: Patients underwent flexible bronchoscopy. Under fluoroscopic guidance, a pigtail catheter was introduced into the abscess cavity, its correct position being confirmed by the injection of contrast medium. The catheter remained in place for a few days and was flushed repeatedly with antibiotics. RESULTS: Fifteen patients (9 males; median age 59 years) underwent 16 BD procedures. A pigtail catheter was successfully inserted and pus was drained from the abscess cavity in 13 procedures (81%) conducted in 12 patients, leading to rapid clinical improvement in 10 of them; resolution of fever occurred a median of 2 days (range <1-4) following pigtail insertion, and patients were discharged after 8 days (range 4-21). The pigtail catheter was extracted after a median of 4 days (range 2-6). CONCLUSION: BD of lung abscesses was achieved in 13 out of 16 procedures, leading to rapid improvement in the majority of patients. This work adds to the existing literature in establishing this procedure as an acceptable therapeutic alternative in selected patients who fail to respond to antibiotics, especially those with an airway obstruction or a fairly central lung abscess.

Erratum to "Endobronchial Enigma: A Clinically Rare Presentation of Nocardia beijingensis in an Immunocompetent Patient".

[This corrects the article DOI: 10.1155/2015/970548.].

Airway bacterial colonization and serum C-reactive protein are associated with chronic obstructive pulmonary disease exacerbation following bronchoscopic lung volume reduction.

INTRODUCTION: Stable chronic obstructive pulmonary disease (COPD) patients often have lower airway bacterial colonization (ABC) which may modulate exacerbation frequency. Data regarding the association between ABC and post-procedural COPD exacerbations following bronchoscopic lung volume reduction (BLVR) are scant. OBJECTIVES: Our aim was to explore the correlation among ABC, serum C-reactive protein (CRP) level and the risk of COPD exacerbation within a month following BLVR. METHODS: Pre-procedure bronchoalveolar lavage (BAL) quantitative bacterial cultures and serum levels of CRP were evaluated in severe COPD patients (N = 70, mean FEV1 = 34.6%) before BLVR by polymeric lung sealant. RESULTS: Colonization with potential pathogenic microorganism (PPM) was observed in 40 (57.1%) patients. Out of 28 patients (40%) who had COPD exacerbation within 30 days of BLVR, 23 (82.1%) had PPM in BAL culture compared with only 14 (33.3%) out of 42 patients who had uneventful procedure (P = 0.0027). Serum CRP level was significantly higher in patients with exacerbation compared with those with no exacerbation (mean 47.8 ± 66.0 mg/L vs 13.05 ± 27.7 mg/L, respectively, P = 0.0063). The combination of CRP level above 3.12 mg/L and PPM growth in BAL was observed in 89.2% of patients with exacerbation compared with only 52.3% of patients without exacerbation (P = 0.0031). CONCLUSIONS: ABC is common in severe COPD patients undergoing BLVR, and along with elevated CRP level both are associated with high risk of immediate post-procedural COPD exacerbation. These patients should be identified, carefully observed and possibly benefit from prophylactic microbiologically directed antibiotic treatment.

Successful Rituximab Therapy in Steroid-Resistant, Cryptogenic Organizing Pneumonia: A Case Series.

Cryptogenic organizing pneumonia (COP) is an interstitial lung disease that is usually responsive to corticosteroid treatment. The treatment of COP has not been studied in randomized controlled trials; thus, treatment decisions are based on practice guidelines. We herein present, for the first time, 4 cases of patients with biopsy-proven COP who did not respond to corticosteroids but benefited from rituximab therapy. This report consists of a retrospective case series of patients who experienced steroid-resistant, biopsy-proven COP. Patients included in this case series suffered from acute or chronic COP and did not respond to corticosteroid treatment for a few weeks to months but later responded to rituximab. In a series of 4 patients, 1 patient had a complete radiological and clinical response after rituximab therapy, and the steroids could be gradually tapered. Three patients had a chronic course but had been able to lower steroid dosage or even discontinue the drug after being treated with rituximab. Since 40% of the patients with COP do not respond to or stay dependent on steroids, we think that even the ability to lower the steroid dosage by using rituximab as a steroid-sparing agent with a good safety profile is worth the effort. However, further studies are warranted.

Safety of Cryo-Transbronchial Biopsy in Diffuse Lung Diseases: Analysis of Three Hundred Cases.

BACKGROUND: Transbronchial biopsy (TBB) which is performed with metal forceps (forceps TBB) has been accepted as a useful technique in establishing diagnoses of diffuse lung diseases (DLDs). The use of cryoprobes to obtain alveolar tissue (cryo-TBB) is a new method which is currently used by our institute as well as others with excellent results. OBJECTIVES: To assess the safety of cryo-TBB compared with conventional forceps TBB. METHODS: We performed a retrospective data evaluation of 300 consecutive patients who underwent cryo-TBB between January 2012 and April 2014 and compared them with historical cases treated with forceps TBB between 2010 and 2012. The results of both diagnostic modalities were compared based on pathological reports. The major complications (significant bleeding and pneumothorax) were compared, along with postprocedural hospitalization. RESULTS: Pneumothorax was observed in 15 cases (4.95%) treated with cryo-TBB versus 9 cases (3.15%) treated with forceps TBB, with no significant difference (p = 0.303). The insertion of a chest tube was necessary in 6 (2%) and 4 (1.3%) of the cases having undergone cryo-TBB or forceps TBB, respectively (p = 0.8). In the cryo-TBB group, bleeding was encountered in 16 cases (5.2%), and it occurred in 13 cases (4.5%) of the forceps TBB group, with no significant difference in rates (p = 0.706). Also, there was no significant difference in hospital admission rates between the groups [cryo-TBB: 10 (3.3%); forceps TBB: 4 (1.44%); p = 0.181]. The safety profile of cryo- and forceps TBB remained the same even when stratified according to indications for TBB, i.e. immunocompromised hosts, patients after lung transplantation and those with DLDs. CONCLUSION: In patients with DLDs, cryo-TBB is as safe as forceps TBB.

Long-term effects of a 12-week exercise training program on clinical outcomes in idiopathic pulmonary fibrosis.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a chronic, devastating, lung disease, with few therapeutic options. Data are limited with respect to the long-term effect of exercise training (ET) in IPF. This study sought to evaluate the long-term effects of a 12-week ET program on clinical outcomes in IPF patients. METHODS: Thirty-four IPF patients were randomly allocated to ET or control groups. ET group participated in a 12-week supervised exercise program, while the control group continued with regular medical treatment alone. Exercise capacity, 30 s-chair-stand test for leg strength, dyspnea, and Saint George's Respiratory Questionnaire (SGRQ) for quality of life (QOL) were assessed at baseline and re-evaluated at 11 months from baseline. In addition, at 30-month time point from baseline, the impact of the 12-week intervention was analyzed with respect to survival and cardio-respiratory-related hospitalizations. RESULTS: Thirty-two patients completed the 12-week intervention and 28 patients (14 in each group) were re-evaluated. At 11-month follow-up, no significant differences between the groups and time effect were demonstrated for most outcomes. ET group showed preserved values at the baseline level while the control group showed a trend of deterioration. Only the 30 s-chair-stand test (mean difference 3 stands, p = 0.01) and SGRQ (mean difference -6 units, p = 0.037) were significantly different between the groups. At 30 months, the survival analysis showed three deaths, eight hospitalizations occurred in the control group versus one death, one lung transplantation and seven hospitalizations in the ET group, with no significant differences between groups. CONCLUSIONS: At 11-month follow-up, the 12-week ET program showed clinical outcomes were preserved at baseline levels with some maintenance of improvements in leg strength and QOL in the ET group. The control group showed a trend of deterioration in the outcomes. At 30 months, the 12-week ET program did not show benefits in prognosis although the study was underpowered to detect such differences. We suggest including ET as a long-term continued treatment and as a core component of pulmonary rehabilitation programs for IPF patients.

Lipid profile and statin use: the paradox of survival after acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: A paradoxical association between cholesterol level and clinical outcome has been suggested, yet never previously established, in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVES: The authors sought to investigate the interaction between long-term survival, lipid profile and statin use in patients after acute exacerbation of COPD (AECOPD). METHODS: A retrospective study evaluating demographic, clinical and laboratory data of 615 consecutive patients admitted for AECOPD over a mean follow-up period of 24.8 months. Kaplan-Meier survival curves and multivariate analysis were used to identify independent prognostic predictors for all-cause mortality. RESULTS: Mean ± standard deviation (SD) age of the study population was 71.8 ± 11.4 years. Unexpectedly, mean serum cholesterol ± SD levels were significantly higher in survivors (N = 340) versus nonsurvivors (N = 275): 181.5 ± 43.6 versus 171.6 ± 57.2 mg/dL, respectively, (P = 0.0043). Median survival for patients with cholesterol levels <150 and >200 mg/dL were 16.0 and 64.4 months, respectively (P = 0.0173). On multivariate analysis, cholesterol level <150 mg/dL was an independent predictor of mortality, irrespective of cardiovascular risk factors (hazard ratio [HR] = 1.8430, 95% confidence interval [CI] = 1.2547-2.7072, P = 0.0019). Statin use had an independent protective effect, regardless of cholesterol level (HR = 0.4924, 95% CI = 0.2924-0.8292, P = 0.0080). CONCLUSIONS: Low cholesterol levels are significantly associated with increased mortality after AECOPD. Nonetheless, as statin treatment was associated with reduced mortality over the entire range of cholesterol levels, its use should be considered in all COPD patients.

Bronchial artery embolization for massive hemoptysis: long-term follow-up.

AIM: Bronchial artery angiography with embolization has become a mainstay in the treatment of massive hemoptysis. Whereas the immediate success rate is high, the reported long-term success rate varies widely among different groups. We aimed to explore the long-term outcome and clinical predictors associated with recurrent bleeding following bronchial artery embolization. METHODS: We reviewed the clinical characteristics, underlying etiologies, procedure details, and outcome of bronchial artery embolization performed for massive hemoptysis between 1999 and 2012. RESULTS: All 52 consecutive patients treated by bronchial artery embolization during the study period were included. The major etiologies of massive hemoptysis were bronchiectasis (mostly post-infectious) in 53.8%, and primary and metastatic lung cancer in 30.8%. The immediate success rate was high (48/52; 92%). Of 45 patients who survived more than 24 hours following bronchial artery embolization, recurrent bleeding did not occur in 19 (42.2%) during a median follow-up period of 60 months (range 6-130 months). Bleeding recurred in 26 (57.7%); within 30 days in 15 (33.3%) and after 1 month in the other 11 (24.4%). The average time to onset of early and late repeat bleeding was 2 and 506 days, respectively. Idiopathic bronchiectasis and lung cancer were associated with a high likelihood of late bleeding recurrence. CONCLUSIONS: Bronchial artery embolization is an effective immediate treatment for massive hemoptysis. Because the bleeding recurrence rate is high in patients with lung cancer or idiopathic bronchiectasis, surgery should be considered in these patients following initial stabilization by bronchial artery embolization. For other underlying etiologies, the long-term outcome is excellent.

D-dimer as a prognostic biomarker for mortality in chronic obstructive pulmonary disease exacerbation.

BACKGROUND: A major barrier to chronic obstructive pulmonary disease (COPD) research and management is lack of easily obtained biomarkers that are predictive of clinically important outcome measures. OBJECTIVES: We sought to investigate in patients admitted for acute exacerbation of COPD (AECOPD) the association of D-dimer (fibrin degradation product) obtained upon admission with in-hospital mortality and postdischarge prognosis. METHODS: Clinical and laboratory data were evaluated in 61 patients admitted for AECOPD in whom D-dimer levels were obtained and in whom venous thromboembolism/pulmonary embolism was excluded. Receiver operating characteristics curve was used to determine the optimal cutoff level for D-dimer that discriminated survivors versus nonsurvivors during index hospitalization, and during follow-up that extended to a median observation period of 62.6 months. RESULTS: Mean (± SD) age of the study cohort was 71.2 ± 10.5 years. Mean D-dimer level in nonsurvivors (n = 12) was significantly higher than in survivors (n = 49): 3.18 ± 0.97 mg/L versus 1.45 ± 1.18 mg/L, respectively, P = 0.0006. D-dimer level >1.52 mg/L predicted in-hospital mortality with a sensitivity and specificity of 100% and 63.6%, respectively. After discharge, median survival of patients with D-dimer above and below 1.52 mg/L were 9.6 and 62.6 months, respectively (hazard ratio = 2.636; 95% confidence interval = 1.271-6.426, P = 0.0111). CONCLUSIONS: Elevated D-dimer is a reliable prognostic marker for both short-term and long-term survival in patients admitted for AECOPD. Prospective studies are required to further establish the appropriate role of D-dimer as a prognostic biomarker in patients with COPD.

Endobronchial Enigma: A Clinically Rare Presentation of Nocardia beijingensis in an Immunocompetent Patient.

Nocardiosis is an opportunistic infection caused by the Gram-positive weakly acid-fast, filamentous aerobic Actinomycetes. The lungs are the primary site of infection mainly affecting immunocompromised patients. In rare circumstances even immunocompetent hosts may also develop infection. Diagnosis of pulmonary nocardiosis is usually delayed due to nonspecific clinical and radiological presentations which mimic fungal, tuberculous, or neoplastic processes. The present report describes a rare bronchoscopic presentation of an endobronchial nocardial mass in a 55-year-old immunocompetent woman without underlying lung disease. The patient exhibited signs and symptoms of unresolving community-acquired pneumonia with a computed tomography (CT) scan that showed a space-occupying lesion and enlarged paratracheal lymph node. This patient represents the unusual presentation of pulmonary Nocardia beijingensis as an endobronchial mass. Pathology obtained during bronchoscopy demonstrated polymerase chain reaction (PCR) confirmation of nocardiosis. Symptoms and clinical findings improved with antibiotic treatment. This patient emphasizes the challenge in making the diagnosis of pulmonary nocardiosis, especially in a low risk host. A literature review presents the difficulties and pitfalls in the clinical assessment of such an individual.

Retrieval of various aspirated foreign bodies by flexible cryoprobe: in vitro feasibility study.

INTRODUCTION: Retrieval of aspirated foreign bodies (FB) by flexible bronchoscopy is challenging. Many types of ancillary equipment, including forceps, grasping claws, snares, balloon-tipped catheters and magnets, have been developed to allow FB extraction using flexible bronchoscopes. The ability to remove a FB by flexible cryoprobe (cryoextraction) depends on the cryoadhesive properties of the retrieved object, which in turn depends on its physical properties. OBJECTIVES: Our aim was to explore ex vivo on a lung model the cryoadhesive properties of various commonly aspirated objects. METHODS: The tested FB compromised of nine organic and nine inorganic commonly aspirated objects. An attempt was made to retrieve each object from a lung model by flexible cryoprobe at 5 and 10 s application time and following rinsing by normal saline. RESULTS: Whereas most organic objects (for example chicken and fish bones) were retrievable by cryoprobe, most inorganic objects (for example safety pin and paper clip) are not retrievable by cryoadhesion. On the other hand, several inorganic objects (for example dental cup) despite their low water content were cryoadhesive. CONCLUSION: FB retrieval by cryoprobe is feasible for many organic and inorganic aspirated objects. However, the cryoadhesive properties of most inorganic FB and several organic objects is unpredictable, hence, if the nature of the FB is known, an identical object should be used to practice the technique of retrieval in vitro, prior to attempting to perform the procedure in the patient.