Pharmacological treatment for Buerger's disease.

Background: Buerger's disease (thromboangiitis obliterans) is a non-atherosclerotic, segmental inflammatory pathology that most commonly affects the small and medium sized arteries, veins, and nerves in the upper and lower extremities. The aetiology is unknown, but involves hereditary susceptibility, tobacco exposure, immune and coagulation responses. In many cases, there is no possibility of revascularisation to improve the condition. Pharmacological treatment is an option for patients with severe complications, such as ischaemic ulcers or rest pain.This is an update of the review first published in 2016.

Objectives: To assess the effectiveness of any pharmacological agent (intravenous or oral) compared with placebo or any other pharmacological agent in patients with Buerger's disease.

Search Methods: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, AMED, the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 15 October 2019. The review authors searched LILACS, ISRCTN, Australian New Zealand Clinical Trials Registry, EU Clinical Trials Register, clincialtrials.gov and the OpenGrey Database to 5 January 2020.

Selection Criteria: We included randomised controlled trials (RCTs) involving pharmacological agents used in the treatment of Buerger's disease.

Data Collection And Analysis: Two review authors, independently assessed the studies, extracted data and performed data analysis.

Main Results: No new studies were identified for this update. Five randomised controlled trials (total 602 participants) compared prostacyclin analogue with placebo, aspirin, or a prostaglandin analogue, and folic acid with placebo. No studies assessed other pharmacological agents such as cilostazol, clopidogrel and pentoxifylline or compared oral versus intravenous prostanoid. Compared with aspirin, intravenous prostacyclin analogue iloprost improved ulcer healing (risk ratio (RR) 2.65; 95% confidence interval (CI) 1.15 to 6.11; 98 participants; 1 study; moderate-certainty evidence), and helped to eradicate rest pain after 28 days (RR 2.28; 95% CI 1.48 to 3.52; 133 participants; 1 study; moderate-certainty evidence), although amputation rates were similar six months after treatment (RR 0.32; 95% CI 0.09 to 1.15; 95 participants; 1 study; moderate-certainty evidence). When comparing prostacyclin (iloprost and clinprost) with prostaglandin (alprostadil) analogues, ulcer healing was similar (RR 1.13; 95% CI 0.76 to 1.69; 89 participants; 2 studies; I² = 0%; very low-certainty evidence), as was the eradication of rest pain after 28 days (RR 1.57; 95% CI 0.72 to 3.44; 38 participants; 1 study; low-certainty evidence), while amputation rates were not measured. Compared with placebo, the effects of oral prostacyclin analogue iloprost were similar for: healing ischaemic ulcers (iloprost 200 mcg: RR 1.11; 95% CI 0.54 to 2.29; 133 participants; 1 study; moderate-certainty evidence, and iloprost 400 mcg: RR 0.90; 95% CI 0.42 to 1.93; 135 participants; 1 study; moderate-certainty evidence), eradication of rest pain after eight weeks (iloprost 200 mcg: RR 1.14; 95% CI 0.79 to 1.63; 207 participants; 1 study; moderate-certainty evidence, and iloprost 400 mcg: RR 1.11; 95% CI 0.77 to 1.59; 201 participants; 1 study; moderate-certainty evidence), and amputation rates after six months (iloprost 200 mcg: RR 0.54; 95% CI 0.19 to 1.56; 209 participants; 1 study, and iloprost 400 mcg: RR 0.42; 95% CI 0.13 to 1.31; 213 participants; 1 study). When comparing folic acid with placebo in patients with Buerger's disease and hyperhomocysteinaemia, pain scores were similar, there were no new cases of amputation in either group, and ulcer healing was not assessed (very low-certainty evidence). Treatment side effects such as headaches, flushing or nausea were not associated with treatment interruptions or more serious consequences. Outcomes such as amputation-free survival, walking distance or pain-free walking distance, and ankle brachial index were not assessed by any study. Overall, the certainty of the evidence was very low to moderate, with few studies, small numbers of participants, variation in severity of disease of participants between studies and missing information (for example regarding baseline tobacco exposure).

Authors' Conclusions: Moderate-certainty evidence suggests that intravenous iloprost (prostacyclin analogue) is more effective than aspirin for eradicating rest pain and healing ischaemic ulcers in Buerger's disease, but oral iloprost is not more effective than placebo. Very low and low-certainty evidence suggests there is no clear difference between prostacyclin (iloprost and clinprost) and the prostaglandin analogue alprostadil for healing ulcers and relieving pain respectively in severe Buerger's disease. Very low-certainty evidence suggests there is no clear difference in pain scores and amputation rates between folic acid and placebo, in people with Buerger's disease and hyperhomocysteinaemia. Further well designed RCTs assessing the effectiveness of pharmacological agents (intravenous or oral) in people with Buerger's disease are needed.