# A Case of Chronic Expanding Hematoma Presenting as a Subcutaneous Mass 24 Years after Konno Procedure

**Authors:** Yoshinobu Watabe, Koji Sato, Taiki Ito, Satoru Wakasa

PMC · DOI: 10.70352/scrj.cr.25-0310 · 2025-10-21

## TL;DR

A rare case of a chronic hematoma appearing as a subcutaneous mass 24 years after heart surgery is reported, highlighting the need for timely surgical treatment.

## Contribution

This paper presents a unique clinical case of a long-term complication following a Konno procedure, emphasizing diagnostic and surgical considerations.

## Key findings

- A 37-year-old man with a history of a Konno procedure presented with a pulsatile subcutaneous mass 24 years later.
- Surgical resection of the hematoma and reconstruction of the right ventricular outflow tract were successfully performed.
- The case highlights the importance of considering chronic expanding hematoma in post-cardiac surgery patients.

## Abstract

Here, we report a very rare case of chronic expanding hematoma presenting as a gradually enlarging subcutaneous pulsatile mass detected 24 years after a Konno procedure.

A 37-year-old man, who had undergone a Konno procedure at the age of 13 for severe aortic stenosis caused by a bicuspid aortic valve, presented with a pulsatile subcutaneous mass that had gradually increased in size over a 4-month period. CT revealed a large mediastinal mass compressing the right ventricular outflow tract, and a transthoracic echocardiogram showed an elevated pressure gradient between the right ventricle and pulmonary artery. Surgical resection of the mass and reconstruction of the right ventricular outflow tract were performed. The mass was completely excised, and the outflow tract was reconstructed using a short valved composite graft. The patient had an uneventful postoperative course.

This case underscores the importance of considering chronic expanding hematoma in the differential diagnosis of new pulsatile masses in patients with a history of cardiac surgery and demonstrates that timely surgical intervention can be performed safely and effectively.

## Linked entities

- **Diseases:** aortic stenosis (MONDO:0042981)

## Full-text entities

- **Diseases:** aortic stenosis (MESH:D001024), Hematoma (MESH:D006406), bicuspid aortic valve (MESH:D000082882), pulsatile masses (MESH:D014012)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12554377/full.md

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Source: https://tomesphere.com/paper/PMC12554377