Guidelines for Clinical Studies with Compression Devices in Patients with Venous Disorders of the Lower Limb

Abstract

Objectives: Endovascular repair of descending thoracic aortic lesions is associated with a substantial risk of perioperative spinal cord ischaemia (SCI) which may lead to permanent paraplegia.We performed a retrospective analysis of our experience in the endovascular treatment of descending thoracic aortic lesions to define the incidence of SCI and to identify factors that contributed to its development.Methods: 67 consecutive patients underwent stent graft repair for descending thoracic aortic lesions including degenerative aneurysm (n ϭ 19), type B dissection (acute n ϭ 2, chronic n ϭ 15), traumatic rupture (acute n ϭ 14, chronic n ϭ 4), penetrating aortic ulcer (n ϭ 5), anastomotic false aneurysm (n ϭ 4), mycotic aneurysm (n ϭ 3) and embolic aortic lesion (n ϭ 1) between June 2000 and June 2005.All procedures were performed with the patient under general anaesthesia and strict blood pressure monitoring. No patient had intra-operative monitoring of spinal evoked potential or cerebrospinal fluid (CSF) drainage to prevent SCI. Neurological evaluation was realized after recovery from general anaesthesia.Fifteen factors, including nature of aortic disease, length of aortic coverage, number of stent-grafts, coverage of the distal third of the thoracic aorta and subclavian artery coverage, were investigated as possible predictors of postoperative SCI.Results: Five patients (7.5%) had postoperative neurological deficits (immediate n ϭ 2, delayed n ϭ 3) referable to SCI. Univariate analysis showed that length of aortic coverage (p Ͻ 0.001) and number of stentgrafts deployed (p ϭ 0.02) were significant predictors of SCI. Multivariate logistic regression analysis showed that length of aortic coverage was the only independent significant predictor of SCI. ROC curve analysis revealed 205 mm of aortic length coverage as the threshold for increased risk of postoperative SCI (p ϭ 0.001), with specificity and sensitivity of 95.2 and 80% respectively.Conclusion: In our study, length of aortic coverage is the only independent predictive factor of SCI after endovascular treatment with 205 mm as a threshold for increased risk. Hence, methods to prevent SCI, especially those aimed at restoration of an adequate spinal cord perfusion pressure, should be offered to patients requiring extensive coverage of the descending thoracic aorta.

An investigation of the ability to produce a defined ‘target pressure’ using the PressCise compression bandage

“…Calculations based on the mean of the repetitions split by position and state gave CIs that were at most 5 mmHg from 50 mmHg. According to the guidelines for categorising the sub‐bandage pressure as strong , we achieved this in all the cases both for the separate repetitions and for the mean values.…”

“…Two pressure sensors were placed on the leg of a healthy female volunteer at the recommended places for sub‐bandage pressure monitoring —at the positions called B1 and C. The B1 position is approximately 10–15 cm proximal to the medial malleolus where the Achilles tendon changes into the calf muscles, while the C position is where the calf is at its maximum girth. The pressure measurement device that was used was PicoPress by Microlab Italia, a sensor that is thin and flexible . A previous study and our own tests showed that PicoPress ® was the most reliable device currently on the market.…”

“…At the present time, different classification systems are used in the USA, UK, France and Germany. A common international compression standard is lacking, but guidelines were established by members of the International Compression Club (ICC) , where a classification system was defined for the clinical studies of compression devices for venous disorders of the lower limbs. According to these guidelines, sub‐bandage pressure of <20 mmHg is categorised as mild , 20–40 mmHg as medium , 40–60 mmHg as strong and ≥ 60 mmHg as very strong .…”

“…Although a common pressure standard might have been agreed upon, the main problem remains; the compression obtained is highly dependent on the individual applying the bandages . Reynolds measured the impact of a training programme on nurses' bandaging skills to establish whether any improvements are maintained over time.…”

“…Recently, a new compression bandage (PressCise, PressCise AB, Sweden) has been developed, and it is claimed that this new bandage provides a predefined pressure, irrespective of leg radius and irrespective of who applies it, provided that the person applying it follows the visual guide for the bandage. This study aims to evaluate this bandage by addressing the following questions: Question 1: Is the expected pressure within the guidelines for strong sub‐bandage pressure, i.e. 40–60 mmHg, achieved when different nurses apply the bandage? Question 2: Is the pressure homogeneous over the leg? Question 3: Is the pressure homogeneous over the states (i.e.…”