Arterial dissection in scuba divers: a potential adverse manifestation of the physiological effects of immersion

Abstract

Introduction: Aortic dissections and dissections of cervical, cerebral, and coronary arteries have been previously reported in scuba divers. These incidents may be the consequence of a variety of physiological effects. We review the reported cases of arterial dissection in scuba divers and discuss potential contributing factors related to immersion and diving.

Methods: Medline, CINAHL Plus, and SPORTDiscus were searched for published reports of arterial dissection and the Australasian Diving Safety Foundation fatality database was searched for additional cases from Australia. Identified cases were recorded and scrutinised for possible contributing factors.

Results: Nineteen cases of arterial dissection, both fatal and non-fatal, were identified. These included cervical or intracranial artery dissection (n = 14), aortic dissection (n = 4), and coronary artery dissection (n = 1). There were 14 male and five female victims; mean age 44 years (SD 14, range 18-65). Contributing factors may include a combination of vasoconstriction and blood redistribution, untreated hypertension, increased pulse pressure, abnormal neck movement or positioning, constrictive and burdensome equipment, exercise, increased gas density and circuit resistance with concomitant elevated work of breathing, atheroma, and possibly the mammalian dive response.

Conclusions: Dissecting aneurysms of the aorta or cervical, cerebral, and coronary arteries should be considered as a potential complication of scuba diving. The development of aneurysms associated with scuba diving is likely multifactorial in pathogenesis. Detailed reporting is important in the evaluation of cases. The potential role of the mammalian dive response as a contributing factor requires further evaluation.

Keywords: Dissecting aneurysm; Dissecting aortic aneurysm; Dissecting coronary artery; Diving; Immersion; Mammalian dive response; Osteogenesis imperfecta.

Figure 1

Pulse and blood pressure recording from a rat trained to swim underwater through a tunnel; down arrow – start of dive; up arrow – end of dive. There is a marked bradycardia beginning immediately at the commencement and ceasing directly at the end of the dive. The blood pressure rise is slightly delayed and persists a short time after the dive. The pulse pressure increases from 20 mmHg to 40 mmHg during submersion. From WM Panneton, with kind permission

Figure 2

Magnetic resonance angiography from case 11; arrows show the dissection site in a sub cranial location where there is a 2 cm long with near total occlusion of the left internal carotid artery. From Prof M. Brodmann with kind permission