Clinical aspects of lower leg compartment syndrome

Abstract

A compartment syndrome is a condition in which increased pressure within a limited space compromises the circulation and function of tissues within that space. Although pathofysiology is roughly similar in chronic exertional and acute compartment syndrome of the lower leg, the clinical presentation and functional outcome are completely different. The chronic version is always exercise related and is therefore generally referred to as Chronic Exertional Compartment Syndrome (CECS). The clinical picture is usually rather mild with a characteristic presentation with disabling, pressure induced, pain while walking or running. Although complaints are generally reversible and don't need emergency treatment, they can cause considerable morbidity and serious limitation of activity. Treatment consists of (elective) percutaneous fasciotomy of the affected compartment. Acute Compartment Syndrome (ACS) is an extremely aggressive form of pressure induced leg pain. It is a complication that is usually related to trauma, but may also follow revascularisation after prolonged critical limb-ischemia. In ACS high intra-compartmental pressures can lead to serious, limb- and even life-threatening conditions, and emergency decompression of the affected compartments through complete dermato-fasciotomies is absolutely indicated to prevent permanent damage. The first part of the thesis deals with CECS. A new diagnostic method was developed using near-infrared spectroscopy. This method can differentiate between saturated and non-saturated Haemoglobin and register tissue saturation in a non-invasive manner by an external electrode. Patients with CECS show very typical tissue de-saturation during exercise. The diagnostic results of this method are good and very comparable to those of invasive intra-compartmental pressure measurements, the standard procedure until now. The natural history of CECS was assessed, by following up on former patients who had not been operated for multiple reasons. Although the syndrome is not self-limiting, many patients learn to live with their complaints after several years. The others clearly benefit from a fasciotomy, even when their test results are in the normal range. In the second part of the thesis ACS was studied, particularly the timing of fasciotomy and prevention of ACS after surgery in the lithotomy position. Prophylactic fasciotomy and therapeutic fasciotomy (performed after development of the first symptoms) were compared in patients with lower leg fractures. Prophylactic operation was superior in prevention of ACS but the morbidity of the fasciotomy itself was larger than expected, with long term sequelae in three quarters of patients. Therefore a prophylactic fasciotomy can only be recommended in patients with a very high risk for development of ACS. Measures were developed to prevent ACS in patients who underwent surgery in the lithotomy position. The measures consist mainly of special leg supports, that do not compress the calves and can be lowered during the major part of surgery, so that tissue perfusion is adequately maintained. The studies in this thesis answer numerous questions on chronic exertional and acute compartment syndrome, but at the same time plenty of matters remain to be investigated, especially in the field of diagnostic modalities and in the selection of patients for operative treatment.