Management of Isolated Anal Strictures in Crohn's Disease.

BACKGROUND: Anorectal stricturing is a particularly morbid manifestation of Crohn's disease resulting in a diminished quality of life related to pain, incontinence, and recurrent operative interventions. OBJECTIVE: To determine the role of medical therapy, endoscopic dilation, and surgical intervention for the treatment of isolated anorectal stricturing. DATA SOURCES: An organized search of MEDLINE, PubMed, EMBASE, Scopus, and the Cochrane Database of Collected Reviews was performed from January 1, 1990 through May 1, 2020. STUDY SELECTION: Full text papers which included management of isolated anorectal strictures in the setting of Crohn's disease. INTERVENTION(S): Medical and surgical management. MAIN OUTCOME MEASURES: Symptomatic relief, need for proctocolectomy. RESULTS: Our search identified a total of 553 papers; after exclusion based on title (n = 430) and abstract (n = 47), 76 underwent full text review with 65 relevant to the management of anorectal strictures. A summary of the retrospective reports suggests that medical therapy can help control luminal inflammation, but fibrosis may ultimately set in resulting in a need for endoscopic or surgical intervention. Surgical options are limited in the anal canal due to inflammation and ulceration and concomitant perianal fistulizing disease. While fecal diversion can provide symptomatic relief, successful restoration of intestinal continuity remains uncommon and most patients ultimately undergo a total proctocolectomy with end ileostomy. LIMITATIONS: Limited literature published, all retrospective in nature. CONCLUSIONS: Despite significant advances in medical and surgical therapy in Crohn's disease over the last decades, there is clearly an unmet need in the management of anorectal strictures in Crohn's disease.

A novel morphological classification for the femoral notch based on MRI: a simple and effective assessment method for the femoral notch.

OBJECTIVE: To propose a novel morphological classification method for notches, which may provide new evidence for notchplasty based on the three-dimensional (3D) features of notches and the risk of anterior cruciate ligament (ACL) injury. MATERIALS AND METHODS: Three hundred individuals in total were included in our study, including 150 patients with ACL ruptures (75 males and 75 females) and 150 age- and gender-matched individuals without ACL ruptures. The notches were divided into four types according to the notch widths at the notch inlet, outlet, and ACL attachment based on the preoperative MRI, the notch volume was calculated, and the risk of ACL injury was compared. The surgical records were reviewed and whether these cases performed notchplasty were collected. RESULTS: The inlet-and-outlet stenosis notch type was associated with smaller notch volume (P = 0.007) and a higher risk of ACL injury (P < 0.001). There were no significant differences in morphological distribution between males and females. The rate of notchplasty in inlet-and-outlet stenosis type was higher than the others. CONCLUSIONS: The new morphological classification method efficiently reflected the association of the notch shape with the 3D notch volume and the risk of ACL injury. The knees with the inlet-and-outlet stenosis notch type and smaller notch volume tended to have a higher risk of ACL injury. Level of evidence Level III, case-control study.

Machine Learning Classification for Assessing the Degree of Stenosis and Blood Flow Volume at Arteriovenous Fistulas of Hemodialysis Patients Using a New Photoplethysmography Sensor Device.

The classifier of support vector machine (SVM) learning for assessing the quality of arteriovenous fistulae (AVFs) in hemodialysis (HD) patients using a new photoplethysmography (PPG) sensor device is presented in this work. In clinical practice, there are two important indices for assessing the quality of AVF: the blood flow volume (BFV) and the degree of stenosis (DOS). In hospitals, the BFV and DOS of AVFs are nowadays assessed using an ultrasound Doppler machine, which is bulky, expensive, hard to use, and time consuming. In this study, a newly-developed PPG sensor device was utilized to provide patients and doctors with an inexpensive and small-sized solution for ubiquitous AVF assessment. The readout in this sensor was custom-designed to increase the signal-to-noise ratio (SNR) and reduce the environment interference via maximizing successfully the full dynamic range of measured PPG entering an analog-digital converter (ADC) and effective filtering techniques. With quality PPG measurements obtained, machine learning classifiers including SVM were adopted to assess AVF quality, where the input features are determined based on optical Beer-Lambert's law and hemodynamic model, to ensure all the necessary features are considered. Finally, the clinical experiment results showed that the proposed PPG sensor device successfully achieved an accuracy of 87.84% based on SVM analysis in assessing DOS at AVF, while an accuracy of 88.61% was achieved for assessing BFV at AVF.

Post-transplant cholangiopathy: Classification, pathogenesis, and preventive strategies.

Biliary complications are the most frequent cause of morbidity, re-transplantation, and even mortality after liver transplantation. In general, biliary leakage and anastomotic and non-anastomotic biliary strictures (NAS) can be recognized. There is no consensus on the exact definition of NAS and different names and criteria have been used in literature. We propose to use the term post-transplant cholangiopathy for the spectrum of abnormalities of large donor bile ducts, that includes NAS, but also intraductal casts and intrahepatic biloma formation, in the presence of a patent hepatic artery. Combinations of these manifestations of cholangiopathy are not infrequently found in the same liver and ischemia-reperfusion injury is generally considered the common underlying mechanism. Other factors that contribute to post-transplant cholangiopathy are biliary injury due to bile salt toxicity and immune-mediated injury. This review provides an overview of the various types of post-transplant cholangiopathy, the presumed pathogenesis, clinical implications, and preventive strategies.

Levenberg-Marquardt Neural Network Algorithm for Degree of Arteriovenous Fistula Stenosis Classification Using a Dual Optical Photoplethysmography Sensor.

This paper proposes a noninvasive dual optical photoplethysmography (PPG) sensor to classify the degree of arteriovenous fistula (AVF) stenosis in hemodialysis (HD) patients. Dual PPG measurement node (DPMN) becomes the primary tool in this work for detecting abnormal narrowing vessel simultaneously in multi-beds monitoring patients. The mean and variance of Rising Slope (RS) and Falling Slope (FS) values between before and after HD treatment was used as the major features to classify AVF stenosis. Multilayer perceptron neural networks (MLPN) training algorithms are implemented for this analysis, which are the Levenberg-Marquardt, Scaled Conjugate Gradient, and Resilient Back-propagation, to identify the degree of HD patient stenosis. Eleven patients were recruited with mean age of 77 ± 10.8 years for analysis. The experimental results indicated that the variance of RS in the HD hand between before and after treatment was significant difference statistically to stenosis (p < 0.05). Levenberg-Marquardt algorithm (LMA) was significantly outperforms the other training algorithm. The classification accuracy and precision reached 94.82% and 92.22% respectively, thus this technique has a potential contribution to the early identification of stenosis for a medical diagnostic support system.

Comparison of inter- and intra-observer reliability among the three classification systems for cervical spinal canal stenosis.

PURPOSE: The aim is to analyze the agreement between different types of physicians in terms of the inter-observer and intra-observer reliability in addition to the agreement between the experienced and non-experienced physicians with respect to three different classification systems for diagnosis of cervical spinal canal stenosis. METHODS: Total nine doctors including experienced group of three doctors and non-experienced group of six doctors classified the patients according to three different classification in an independent, blinded manner using magnetic resonance imaging (MRI) to diagnose cervical canal stenosis. MRI slice included sagittal plane (midline cut) and an image slice from each horizontal plane that penetrated the right center of each disk (C3-4, C4-5, C5-6, and C6-7) was made by PPT format. RESULTS: For the inter-observer reliability, Vaccaro et al.'s classification system showed the excellent reproducibility, followed by Muhle et al. and Kang et al. All three classification systems showed excellent reproducibility and substantial agreement in terms of the intra-observer reliability. CONCLUSIONS: All three classification systems showed excellent reproducibility and also displayed a substantial agreement. The classification system used by Vaccaro et al. was proven to be a method with substantial agreement both in the experienced group and the non-experienced group. It can be a useful classification system for simplifying communication among all physicians.

Clinical usefulness of transabdominal ultrasonography prior to patency capsule for suspected small-bowel strictures.

OBJECTIVE: Patency capsule (PC) examination has made it possible to perform capsule endoscopy (CE) in patients with a suspected small-bowel stricture. However, PC has some drawbacks, so we assessed the usefulness of transabdominal ultrasonography (TUS) prior to PC in patients with suspected small-bowel strictures to avoid unnecessary PC examination. PATIENTS AND METHODS: Fifty-two patients who underwent TUS prior to PC were enrolled in this study. TUS findings were classified as follows: intestinal narrowing and distension at the oral side (Type A); extensive bowel wall thickening (Type B); focal bowel wall thickening (Type C) or no abnormality detected (Type D). We evaluated the TUS and PC findings for the detection of small-bowel strictures. RESULTS: Double-balloon endoscopy (DBE) revealed small-bowel strictures in 13 of 50 patients (26%). TUS yielded Type B or C findings in 12 of 13 patients (92%), while PC revealed strictures in all 13 patients. In Crohn's disease (CD) patients with Type B TUS findings, 8 of 9 (89%) had small-bowel strictures on DBE. However, only two of six non-CD patients (33%) with Type B TUS findings had small-bowel strictures. The incidence of Type B strictures was significantly higher in CD patients. CONCLUSIONS: CD patients with Type B TUS findings should not undergo PC or CE because of the high rate of small-bowel strictures. Non-CD patients diagnosed with Type B TUS strictures, as well as patients diagnosed with Type C or D strictures should undergo CE after confirming small-bowel patency using PC.

Endoscopic therapy in inflammatory bowel diseases (with videos).

Endoscopic therapies are important modalities in the treatment of IBD, adjunct to medical and surgical approaches. These therapeutic techniques are particularly useful in the management of IBD-associated or IBD surgery­associated strictures, fistulas, and sinuses and colitis-associated neoplasia. Although the main focus of endoscopic therapies in IBD has been on balloon stricture dilation and ablation of adenoma-like lesions, new endoscopic approaches are emerging, including needle-knife stricturotomy, needle-knife sinusotomy, endoscopic stent placement, and fistula tract injection. Risk management of endoscopy-associated adverse events is also evolving. The application of endoscopic techniques in novel ways in the treatment of IBD is just beginning and will likely expand rapidly in the near future.

Clinical usefulness of classification by transabdominal ultrasonography for detection of small-bowel stricture.

OBJECTIVE: To assess the clinical usefulness of transabdominal ultrasonography (TUS) for detection of small-bowel stricture. PATIENTS AND METHODS: Subjects were 796 patients undergoing double-balloon endoscopy (DBE), December 2003-October 2011. All underwent TUS prior to DBE. The TUS findings were classified by type as intestinal narrowing and distension at the oral side (Type A); extensive bowel wall thickening (Type B); focal bowel wall thickening (Type C) or no abnormality detected (Type D). We compared TUS findings against DBE findings with respect to small-bowel stricture, defined as failure of the enteroscope to pass through the small bowel. RESULTS: Small-bowel stricture was detected by DBE in 11.3% (90/796) of patients. Strictures resulted from Crohn's disease (n = 36), intestinal tuberculosis (n = 24), malignant lymphoma (n = 9), ischemic enteritis (n = 6), NSAID ulcer (n = 5), radiation enteritis (n = 2), surgical anastomosis (n = 2) and other abnormalities (n = 6). Stricture was detected by TUS in 93.3% (84/90) of patients, and each such stricture fell into one of the three types of TUS abnormality. The remaining 6 strictures were detected only by DBE. DBE-identified strictures corresponded to TUS findings as follows: 100% (43/43) to Type A, 59.1% (29/49) to Type B, 14.8% (12/81) to Type C and 1% (6/623) to Type D. Correspondence between stricture and the Type A classification (vs. Types B, C and D) was significantly high, as was correspondence between stricture and Type B (vs. Types C and D). CONCLUSIONS: TUS was shown to be useful for detecting small-bowel stricture. We recommend performing TUS first when a small-bowel stricture is suspected.

Predictors of recurrent stroke in patients with symptomatic intracranial arterial stenosis.

BACKGROUND AND PURPOSE: Our goal was to investigate whether initial ischemic lesion pattern can predict stroke recurrence in patients with symptomatic intracranial arterial stenosis. METHODS: Of the Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis (TOSS)-2 trial participants, we included patients who underwent diffusion-weighted imaging and fluid attenuation inversion recovery imaging at baseline with a follow-up fluid attenuation inversion recovery imaging at 7 months. Based on the diffusion-weighted imaging findings, we classified the initial ischemic lesion patterns according to location (subcortical versus cortical versus subcorticocortical) and multiplicity (single versus multiple). We also evaluated the occurrence of new ischemic lesions on follow-up fluid attenuation inversion recovery as well as clinical stroke in the symptomatic intracranial arterial stenosis territory. RESULTS: Of 353 patients included in this study, 44 (12.5%) and 13 (3.7%) patients had new ischemic lesions and clinical recurrent stroke in the initial symptomatic intracranial arterial stenosis territory, respectively. On multivariable analysis, the initial lesion patterns of subcorticocortical and multiple lesions were independent predictors of new ischemic lesions in the symptomatic intracranial arterial stenosis territory (OR, 3.01; 95% CI, 1.33-7.01; P=0.03; OR, 2.81; 95% CI, 1.34-5.9; P=0.006). These patterns also predicted clinical recurrent stroke. CONCLUSIONS: Subcorticocortical lesions and multiple lesions are radiological predictors of recurrent ischemic stroke in symptomatic patients with intracranial arterial stenosis. Clinical Trial Registration- URL: www.clinicaltrials.gov. Unique identifier: NCT00130039.

Classification of probe-based confocal laser endomicroscopy findings in pancreaticobiliary strictures.

BACKGROUND AND STUDY AIMS: The accurate diagnosis of indeterminate pancreaticobiliary strictures presents a clinical dilemma. Probe-based confocal laser endomicroscopy (pCLE) offers real-time in vivo microscopic tissue examination that may increase sensitivity for the detection of malignancy. the objective of this study was to develop and validate a standard descriptive classification of pcle in the pancreaticobiliary system. PATIENTS AND METHODS: A total of 102 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) with pCLE to assess indeterminate pancreaticobiliary strictures were enrolled in a multicenter registry; 89 of these patients were evaluable. Information and data on the following were collected prospectively: clinical, ERCP, tissue sampling, pCLE, and follow-up. A uniform classification of pCLE findings ("Miami Classification") was developed, consisting of a set of image interpretation criteria. Thereafter, these criteria were tested through blinded consensus review of 112 randomized pCLE videos from 47 patients, and inter-observer variability was assessed in 42 patients . RESULTS: A consensus definition of the specific criteria of biliary and pancreatic pCLE findings for indeterminate strictures was developed. Single-image interpretation criteria did not have a high enough sensitivity for predicting malignancy. However, combining two or more criteria significantly increased the sensitivity and predictive values. The characteristics most suggestive of malignancy included the following: thick white bands (>20 µm), or thick dark bands (>40 µm), or dark clumps or epithelial structures. These provided sensitivity, specificity, positive predictive value, and negative predictive value of 97%, 33%, 80%, and 80% compared with 48%, 100%, 100%, and 41% for standard tissue sampling methods. Inter-observer variability was moderate for most criteria. CONCLUSION: The Miami Classification enables a structured, uniform, and reproducible description of pancreaticobiliary pCLE. Combining individual characteristics improves the sensitivity for the detection of malignancy.

[Some aspects of classification and treatment strategy of iatrogenic bile duct injury].

Iatrogenic bile duct injury continues to be an important clinical problem, resulting in serious morbidity, and occasional mortality, to patients. None of the classification system is universally accepted and worldwide used as each has its own limitation. This article reviews the various classification systems of bile duct injury. Traditionally, biliary injuries have been classified using the Bismuth's classification. This classification does not encompass the whole spectrum of injuries during laparoscopic cholecystectomy. Strasberg's classification made Bismuth's classification much more comprehensive by including various other types of extrahepatic bile duct injuries. Our own classification is simple enough, embraces the majority possible variants of bile duct injuries and convenient in clinical use.

[The application of thyroid alar cartilage in the reconstruction of subglottic stenosis for children].

Objective: To explore the application value of thyroid alar cartilage(TAC) in the laryngotracheal reconstruction of subglotticstenosis in the paediatric population. Methods: Twelve patients(7 males,5 females; range from 2.3 to 12.0 years) with subglotticstenosis who had undergone laryngotracheal reconstruction procedures at our hospital fromSeptember 2016 to July 2018 were analyzed retrospectively.The degree of stenosis was classified according to Myer-Cotton classification system:grade Ⅱ(n=4),grade Ⅲ(n=6) and grade Ⅳ(n=2). The stenosis planes were subglotticbut did not exceed the 3rd tracheal cartilage ring. Results: Of all 12 patients, 11 were decannulated and 1 failed. All patients with grade Ⅱ and Ⅲ patients were decannulated at one procedure. There were no severe complications such as tube dislogement,asphyxia and unhealed wound. Conclusions: The TAC for widening laryngotracheal lumen is relatively simple and reliable for laryngotracheal reconstruction in the pediatric population with subglottic stenosis. This would't cause any structural damage to the laryngeal cavity.

Predictive criteria of response to endoscopic treatment for severe strictures in primary sclerosing cholangitis.

BACKGROUND: The aim of this study was to identify predictive criteria of improvement after endoscopic treatment (ET) for severe strictures of extrahepatic bile ducts in patients with primary sclerosing cholangitis (PSC). METHODS: PSC patients who had at least one ET for severe stricture were included. Features of magnetic resonance cholangiography (MRC), performed before ET, were evaluated according to a standard model of interpretation, and a radiologic qualitative score of probability of improvement after ET was built. Score 3 (likely) was given in case of severe common bile duct (CBD) stricture with marked dilatation without severe strictures of upstream ducts, Score 1 (unlikely) was given in case of severe multiple strictures of secondary ducts without biliary dilatation and Score 2 (undeterminate) was given to an intermediate pattern. The response to ET was assessed at 2 months (T2-response) from the last ET and at 12 months (T12-response) from inclusion. RESULTS: Thirty-one patients were included. All had severe stricture (reduction ≥ 75% of the diameter) of CBD and 50% had severe stricture of right and/or left hepatic duct (LHD) at MRC before ET. According to the qualitative score, 16 patients had Score 3, 7 had Score 1 and 9 had Score 2. T12-response was obtained in 50% of patients. In univariate analysis, short LHD strictures, bilirubin, transaminases, pruritus and Score 3 were associated with T12-response. Increased bilirubin and transaminases were independent predictive factors of T12-response (HR 24, 95% CI: 3.4-170.4, P = 0.001 and 23.8, 95% CI: 3.4-169.4, P = 0.002, respectively). CONCLUSION: MRC, together with biochemical features, may contribute to identify the PSC patients who are likely to be improved after ET for severe strictures of extrahepatic bile ducts.

Tracheal agenesis in a new born: lessons learnt.

Tracheal agenesis is a rare but fatal congenital tracheal malformation. Lack of prenatal symptom and a typical clinical presentation lead to failure to arrive at a correct diagnosis and confusion during resuscitation. We report a case of a newborn male child with type 2 tracheal agenesis. Despite a typical presentation, diagnosis was delayed after unsuccessful intubation, examination under anaesthesia and emergency tracheostomy. The embryology, diagnostic criteria and potential treatment options are discussed. This case report is valuable in increasing awareness of this rare condition and will help us in being better prepared in managing these children. Future studies should aim to find the optimal replacement for the tracheal.

Interventional IBD: The Role of Endoscopist in the Multidisciplinary Team Management of IBD.

Inflammatory bowel disease (IBD) has been traditionally managed by IBD medical doctors or IBDologists and colorectal surgeons. Complications related to IBD and IBD surgery, such as stricture, fistula, and abscess, are common. For the past decade, endoscopic therapy has emerged as a valid treatment option for those complications. Endoscopic therapy provides more effective therapy for those structural complications than medical treatment, while being a less invasive approach than surgery. Endoscopic therapy plays a growing role in bridging medical and surgical therapies and is becoming an important component in the multidisciplinary approach to complex IBD. In fact, endoscopic therapy has become the treatment of choice for anastomotic stricture and anastomotic sinus. The role of endoscopic resection of colitis-associated neoplasia is currently being explored. Interventional IBD is intellectually and technically challenging. We are calling for proper teaching and training of our next generation of IBD interventionists.

Pattern of pressure gradient alterations after venous sinus stenting for idiopathic intracranial hypertension predicts stent-adjacent stenosis: a proposed classification system.

OBJECTIVE: Venous sinus stenting (VSS) is a safe and effective treatment for idiopathic intracranial hypertension (IIH) with angiographic venous sinus stenosis. However, predictors of stent-adjacent stenosis (SAS) remain poorly defined. METHODS: We performed a retrospective review of 47 patients with IIH and intracranial venous stenosis who underwent VSS with pre- and post-stent venography. Patient characteristics, treatments and outcomes were reviewed. Changes in pressure gradient after VSS were classified according to pattern of gradient resolution into types I-III. RESULTS: Type I gradient resolution, in which mean venous pressure (MVP) in the transverse sinus (TS) decreases towards MVP in the sigmoid sinus (SS), occurred in 18 patients (38.3%). Type II gradient resolution pattern, in which SS MVP increases towards that in the TS, occurred in 7patients (14.9%). Type III pattern, in which MVP equilibrates to a middle value, occurred in 22patients (46.8%). SAS occurred in 0%, 28.6%, and 22.7% of patients in types I, II and III, respectively. Compared with patients with type I gradient resolution, SAS was more common in those with type II (p=0.0181) and type III (p=0.0306) patterns. CONCLUSIONS: The pattern of change in the trans-stenosis venous pressure gradient may be predictive of SAS and is a useful tool for classifying the response of the venous obstruction to stenting. A type I pattern appears to represent the ideal response to VSS. Some patients with type II and III changes, particularly if they have other predictors of recurrent stenosis, may benefit from longer initial stent constructs.

TIA patients with higher ABCD3-I scores are prone to a higher incidence of intracranial stenosis, unstable carotid plaques and multiple-vessel involvement.

The ABCD3-I criteria have proved to be effective for use in regular clinical practice to assist in transient ischemic attack (TIA) risk stratification and treatment. In this prospective study we aimed to explore the relationships between risk stratification and arterial stenosis location, carotid plaque morphology and vessel involvement in 90 TIA patients, stratifying risk by ABCD3-I scores. Clinical variables such as total cholesterol, triglyceride, low-density lipoprotein cholesterol, glycosylated hemoglobin, homocysteine and high-sensitive C-reactive protein levels were recorded. The endpoint was subsequent stroke at seven-day follow-up. Ninety patients were divided into three risk groups on the basis of their ABCD3-I scores. The results revealed that patients with higher ABCD3-I scores showed a higher occurrence of intracranial stenosis (P < 0.05), less organized carotid plaques (P < 0.05) and multiple-vessel involvement (P < 0.05).

Extended and treatment-oriented classification of parotid duct stenosis.

OBJECTIVES/HYPOTHESIS: To provide an extended and treatment-oriented classification of parotid duct stenosis that might be useful in the management of this condition. STUDY DESIGN: Retrospective study in a tertiary referral center. METHODS: A total of 550 symptomatic stenoses of the parotid gland excretory duct in 445 patients were analyzed. Sialendoscopy was performed with semirigid endoscopes. The tissue quality, location, grade of luminal narrowing, and length and number of the stenoses were assessed. RESULTS: Inflammation-dominant stenosis (type 1) was found in 8.9% of the patients, web-associated fibrous stenosis (type 2) in 19.5%, and fibrous (type 3) in 71.6%. Multiple stenoses (≥3) were found in 2.8% of patients, and bilateral stenoses in 11.9%. Type 1 stenoses differed significantly from type 3 stenoses, with lower grades. Type 3 stenoses showed significantly higher grades of luminal narrowing than the other two types (P = .0001). Type 2 stenoses were significantly shorter in comparison with the other two types (P = .0001). Multiple stenoses were observed significantly more often in type 2 than in type 3 stenoses (P = .0001). Due to these differences, the type of stenosis appears to be the most important criterion in the treatment-oriented classification. CONCLUSIONS: Significant differences between the different stenoses were observed. Type 1 stenosis may be considered as a precursor of type 3 stenosis, but type 2 stenosis showed significantly different characteristics. The differences prescribed in this classification may be helpful in the management of parotid duct stenoses. LEVEL OF EVIDENCE: 4. Laryngoscope, 2016 127:366-371, 2017.

[Non transplant-related constrictive bronchiolitis in adults]. / Bronchiolites constrictives de l'adulte, hors contexte de transplantation.

INTRODUCTION: The term bronchiolitis refers to inflammatory disorders of the bronchioles. Constrictive bronchiolitis is the type most frequently encountered. STATE OF THE ART/PERSPECTIVES: The main clinical manifestations include the development of exertional dyspnoea and fixed airflow obstruction. Chest x-ray findings are usually unhelpful, but CT scanning may reveal a mosaic pattern on expiration. Peripheral micronodules are less frequently seen. The causes of constrictive bronchiolitis are numerous. The diagnosis may be clear from the clinical context when a causative event or predisposing condition can be identified (lung or bone marrow transplantation, toxic fume or gas inhalation, rheumatoid arthritis); in other conditions, a stepwise approach to the diagnosis is usually recommended in order to exclude other causes of subacute or chronic obstructive disease. Formal diagnosis requires histological examination of surgical lung biopsies. Despite corticosteroid administration, respiratory failure usually develops. Specific inhibitors of pro-inflammatory cytokines may offer a new and promising therapeutic approach. CONCLUSIONS: If the clinical context or the radiology and clinical findings are not highly suggestive of a constrictive bronchiolitis, a surgical lung biopsy should be considered.