Cardiovascular ochronosis

Ease of sutureless aortic valve replacement in a patient with unexpected ochronosis: a case report

BACKGROUND

Alkaptonuria is a rare congenital metabolic disorder characterized by homogentisic acid accumulation in body cartilage and connective tissues due to a deficient homogentisic acid dioxygenase enzyme. This disorder manifests in various clinical symptoms, including spondyloarthropathy, ocular and dermal pigmentation, genitourinary tract obstruction by ochronosis stones, and cardiovascular system involvement. Cardiac ochronosis is a rare manifestation of alkaptonuria that may present as aortic stenosis, sometimes accompanied by other cardiovascular complications.

CASE PRESENTATION

We report an unexpected case of ochronosis diagnosed during cardiac surgery. Due to the fragile, thin, and atheromatous nature of the ascending aorta in patients with ochronosis, we opted for a sutureless aortic valve replacement procedure. This approach appears to be more suitable for patients with ochronosis.

CONCLUSIONS

Although cardiac ochronosis is rare, surgeons should remain vigilant and consider the possibility of this condition when examining patients with aortic valve stenosis, paying close attention to the clinical manifestations of alkaptonuria.

Surgical management of calcific valvular and coronary disease in a patient with alkaptonuria: a case report

Background

Alkaptonuria is a rare metabolic disease that causes an increase in homogentisic acid (HGA) due to a lack of enzymatic activity. Commonly, accumulation of HGA presents with dark discoloration of skin and other tissues, also known as ochronosis. Additionally, alkaptonuria can result in other clinical manifestations, including arthritis and cardiac disease. This case highlights alkaptonuria-related cardiac disease and challenges that cardiac surgery teams may face when treating this patient population.

Case summary

A 62-year-old male with a history of alkaptonuria, Hodgkin's lymphoma treated with chemoradiation, hypertension, and hyperlipidaemia originally presented with shortness of breath in the setting of known cardiac disease. Cardiac work-up demonstrated aortic stenosis, mitral stenosis, and multivessel coronary artery disease requiring aortic valve replacement, mitral valve replacement, and coronary artery bypass grafting. During the operation, significant discoloration of tissue was observed. This correlated with areas of severe calcification, which was noted throughout both valves. Extensive debridement was required prior to proceeding to valve replacements. Additionally, near-infrared spectroscopy failed to provide accurate measurements of cerebral oxygenation.

Discussion

Alkaptonuria is correlated with cardiovascular disease, particularly valvular disease. Intraoperatively, these patients may exhibit noticeable discoloration and severe calcification of various tissues. Additionally, traditional infrared-based methods of cerebral oxygenation monitoring may not be reliable; however, other options of cerebral monitoring may be feasible. With proper pre-operative planning, however, patients with alkaptonuria may safely undergo cardiac surgery.

Minocycline induced discoloration of the aortic intima and valve: A case report

CASE REPORT

Ochronosis refers to the blue-black discoloration of connective tissue. While cardiovascular ochronosis has been described resulting from alkaptonuria, it may also result from chronic minocycline use which is exceedingly rare. Cardiovascular ochronosis often presents with insidious development, often identified incidentally during aortic valve replacement (AVR). Herein, we describe the case of a 71-year-old male undergoing AVR and coronary artery bypass grafting found to have minocycline-induced ochronosis of the aortic valve and aorta.

CONCLUSIONS

Given the rarity of this case, descriptions of cardiovascular ochronosis cases secondary to minocycline use are imperative in ensuring that it is on the differential diagnosis when identified by others in future cases. Additional care must be taken intraoperatively to ensure that the correct anatomy is identified as discoloration hinders visualization of the anatomy potentially resulting in unintentional consequences such as heart block or perivalvular leak as traditional visual cues for suture placement are distorted.

Incidental diagnosis of ochronosis by aortic valve replacement

Alkaptonuria is a rare inherited metabolic disease caused by homogentisic acid oxidase enzyme deficiency. Homogentisic acid formed during phenylalanine and tyrosine metabolism cannot be further metabolized and accumulates due to this enzyme deficiency. Some of the homogentisic acid that cannot be removed by metabolism is excreted with urine, some of it causes this accumulation known as ochronosis, which is characterized by dark pigmented color change in tissues. The classic clinical triad of the disease is darkening of the urine color, degenerative arthritis in the joints and dark colored pigmentation in the connective tissue. Herein, we present a case of ochronosis detected incidentally during aortic valve replacement with the diagnosis of aortic insufficiency.

Ochronotic heart disease leading to severe aortic valve and coronary artery stenosis

Cardiac ochronosis is a rare disease, estimated to affect 1 in 250,000 persons. While there is extensive evidence of the musculoskeletal alterations of the disease, cardiac involvement has not been widely studied and most information we currently have derives from case reports and case series. We report the case of a 64-year old patient with a known history of alkaptonuria who presented with dyspnea and weight loss. On evaluation, he was found to have severe aortic stenosis, coronary artery disease, and interventricular septal hypertrophy. Surgery revealed extensive ochronotic pigment deposition affecting the cardiac septum, both internal thoracic arteries, the native coronary arteries, and the aortic valve. Ochronotic heart disease is an often disregarded presentation of alkaptonuria. More information is needed on the course of the disease, as well as long-term outcomes after valve replacement surgery and/or coronary artery bypass grafting in patients with alkaptonuria.