Hyperbaric oxygen as effective adjuvant therapy in the treatmentof distal calcific uraemic arteriolopathy

Is there a role for hyperbaric oxygen therapy in the treatment of refractory wounds of rare etiology?

INTRODUCTION

Delayed wound healing indicates wounds that have failed to respond to more than 4-6 weeks of comprehensive wound care. Wounds with delayed healing are a major source of morbidity and a major cost to hospital and community healthcare providers. Hyperbaric oxygen therapy (HBOT) is a treatment designed to increase the supply of oxygen to wounds and has been applied to a variety of wound types. This article reviews the place of HBOT in the treatment of non-healing vasculitic, calcific uremic arteriolopathy (CUA), livedoid vasculopathy (LV), pyoderma gangrenosum (PG) ulcers.

METHODS

We searched electronic databases for research and review studies focused on HBOT for the treatment of delayed healing ulcers with rare etiologies. We excluded HBOT for ulcers reviewed elsewhere.

RESULTS

We included a total of three case series and four case reports including 63 participants. Most were related to severe, non-healing ulcers in patients with vasculitis, CUA, LV, and PG. There was some evidence that HBOT may improve the healing rate of wounds by increasing nitric oxide (NO) levels and the number of endothelial progenitor cells in the wounds. HBOT may also improve pain in these ulcers.

CONCLUSION

We recommend the establishment of comprehensive and detailed wound care registries to rapidly collect prospective data on the use of HBOT for these problem wounds. There is a strong case for appropriately powered, multi-centre randomized trials to establish the true efficacy and cost-effectiveness of HBOT especially for vasculitis ulcers that have not improved following immunosuppressive therapy.

Patient Outcomes and Factors Associated with Healing in Calciphylaxis Patients Undergoing Adjunctive Hyperbaric Oxygen Therapy

Calcific uremic arteriolopathy, also known as calciphylaxis, is a rare syndrome of small vessel calcification of unknown etiology causing painful, violaceous skin lesions that progress to form chronic non-healing ulcers and gangrene. Hyperbaric oxygen therapy (HBOT) can be used as adjunctive therapy in the treatment of these ulcers. However, due to paucity of cases, there is limited data on the clinical benefit of HBOT and identifying factors associated with healing. The purpose of this study was to determine patient outcomes and factors associated with healing in patients with calciphylaxis undergoing HBOT. A retrospective chart review was completed on patients who were diagnosed with calciphylaxis and had hyperbaric medicine consultation between May 2012 and January 2016. Clinical outcomes, demographics, risk factors, laboratory values, wound distribution, and HBOT profiles were collected and analyzed. We identified 8 patients. Out of 8 patients consulted for calciphylaxis, five were consented and underwent HBOT (2 males and 3 females). All had coexisting ESRD and Diabetes. All males were able to tolerate being in the chamber and received therapeutic treatments (at least 20 HBOT) with complete resolution of ulcers. HBOT was discontinued in one female due to an inconsistent biopsy report and two others due to death secondary to septic shock or respiratory arrest and severe uremia. Calciphylaxis is a devastating disease with a high mortality rate. Our results demonstrated a positive response to HBOT especially when receiving at least 20 treatments. A majority of calciphylaxis cases are females and indeed female gender has been cited as a risk factor for this disease. However, current literature has not conferred a relationship between gender nor the number of HBOT received and outcomes. Our results showed that males had a more favorable outcome provided they received at least twenty HBOT. Further prospective studies are needed to elucidate these outcomes.

Calciphylaxis: from the disease to the diseased

Calciphylaxis, or calcific uremic arteriolopathy, is a vascular ossification-calcification disease involving cutaneous or visceral arterioles, with ischemic damage of the surrounding tissues, usually in the setting of chronic kidney disease. Pathogenesis is still unclear and probably comprises the participation of vascular smooth muscle cells, endothelial cells and macrophages surrounded by a uremic and/or pro-calcifying environment. According to the original concept of calcific uremic arteriolopathy coined by Hans Selye, risk factors may be divided into sensitizers and challengers and their knowledge is useful in clinical practice to pre-emptively identify both uremic and non-uremic 'at risk' patients and guide treatment. Systemic calcific uremic arteriolopathy is a rarity. Cutaneous calcific uremic arteriolopathy is more frequent and clinically presents as a first phase of cutaneous hardening and erythema, followed by a second phase of ulcerations and scars; these two phases are probably associated with the initial development of arteriolar lesion and tissue ischemic damage, respectively. Clinical history, physical examination, laboratory analysis, histology and imaging are the main tools to exclude important differential diagnoses and obtain a definitive diagnosis. Treatment is generally unrewarding and consists of rigorous control of comorbid conditions, anti-oxidant, anti-inflammatory and antithrombotic strategies, avoidance of iatrogeny and wound and pain management. Prognosis remains poor in terms of morbidity and mortality. Efforts should be made towards a greater awareness of calcific uremic arteriolopathy, development of better therapies and improvement of clinical outcomes.

Calcific uremic arteriolopathy in end stage renal disease: pathophysiology and management

BACKGROUND

Calcific uremic arteriolopathy (CUA), a debilitating condition with high morbidity and mortality, is most commonly seen in patients with kidney disease. The pathophysiology of CUA is multifactorial, leading to a disruption in the balance between factors that promote and those that inhibit calcification, although the exact pathophysiological mechanisms of CUA remain to be elucidated.

METHODS

This review provides an overview of the pathophysiology, clinical presentation and diagnosis, and treatment of CUA.

RESULTS

Diagnosis of CUA requires a high degree of suspicion; skin biopsy with histological examination remains the gold standard to confirm the diagnosis. Treatment of CUA requires a multidisciplinary approach.

CONCLUSION

With a high degree of clinical suspicion and early diagnosis, an aggressive multifactorial treatment approach involving optimal wound management, minimization/avoidance of risk factors and precipitating causes, and correction of calcium-phosphorus abnormalities can significantly improve patient outcomes.