Medical College, Aga Khan University, Stadium Road, Karachi, 74800, Pakistan.
Department of Medicine, Aga Khan University Hospital, Karachi, Pakistan.
J Med Case Rep. 2024 Jul 8;18(1):313. doi: 10.1186/s13256-024-04643-8.
Pulmonary arteriovenous malformations are a relatively uncommon medical condition, affecting roughly 1 in every 2500 individuals. Of those suffering from pulmonary arteriovenous malformations, 80% have an underlying genetic condition: hereditary hemorrhagic telangiectasia.
We present the case of a 20-year-old Pakistani male with a history of persistent slower-onset frontal headaches that increased in severity within the course of the day. His hemoglobin was 18 g/dl, indicating polycythemia, for which he had undergone seven venesections in a month previously. His physical examination was unremarkable. His computed tomography scan depicted multiple dilated tortuous vessels with branching linear opacities in the right lower lobe of the lungs. The multiple feeding arteries were supplied by the right main pulmonary artery, and the large draining veins led to the right inferior pulmonary vein. This was identified as a diffuse pulmonary arteriovenous malformation. He was recommended for a right pulmonary artery angiogram. It showed multiple tortuous vessels with a nidus and large draining veins-features of a diffuse arteriovenous malformation in the right lower lobe of the lung consistent with the computed tomography scan. Embolization of two of these vessels feeding the arteriovenous malformation was conducted, using Amplatzer Vascular plug 2, whereas multiple pushable coils (five coils) were used for embolizing the third feeding vessel. This achieved 70-80% successful embolization of right pulmonary AVM; however, some residual flow was still seen in the arteriovenous malformation given the complexity of the lesion. Immediately after, his oxygen saturation improved from 78% to 96%.
Diffuse pulmonary arteriovenous malformations, as seen in this patient, are rare, accounting for less than 5% of total pulmonary arteriovenous malformations diagnosed. The patient presented with a complaint of progressive frontal headaches, which can be attributed to low oxygen saturation or the presence of a cerebral arteriovenous malformation. There was no history of hereditary hemorrhagic telangiectasia in the patient's family. Furthermore, although most patients with hereditary hemorrhagic telangiectasia and hence pulmonary arteriovenous malformation have complaints of iron-deficiency anemia, our patient in contrast was suffering from polycythemia. This can be explained as a compensatory mechanism in hypoxemic conditions. Moreover, the patient had no complaint of hemoptysis or epistaxis, giving a varied presentation in comparison with a typical pulmonary arteriovenous malformation.
肺动静脉畸形是一种相对罕见的医学病症，每 2500 个人中约有 1 人受到影响。在患有肺动静脉畸形的人群中，80%存在潜在的遗传状况：遗传性出血性毛细血管扩张症。
我们介绍一位 20 岁的巴基斯坦男性病例，其病史为持续性、发作较慢的额部头痛，且在一天内逐渐加重。他的血红蛋白为 18 g/dl，表明存在红细胞增多症，此前一个月他已进行了 7 次静脉放血。他的体格检查无明显异常。他的计算机断层扫描显示右肺下叶有多个扩张扭曲的血管，伴分支线性不透明。多个供血动脉由右肺动脉主干供应，大引流静脉通向右下肺静脉。这被确定为弥漫性肺动静脉畸形。他被推荐进行右肺动脉血管造影。造影显示多个扭曲的血管伴病灶和大引流静脉，这些特征与计算机断层扫描一致，提示右肺下叶弥漫性动静脉畸形。使用 Amplatzer 血管塞 2 对其中两条供血血管进行了栓塞，对第三条供血血管使用了多个可推送的线圈（5 个线圈）进行栓塞。这使右肺 AVM 的栓塞成功率达到 70-80%；然而，由于病变复杂，仍可见动静脉畸形中有残留血流。栓塞后，他的血氧饱和度从 78%提高到 96%。
如本例所见，弥漫性肺动静脉畸形较为罕见，占诊断出的所有肺动静脉畸形的不到 5%。该患者主诉进行性额部头痛，这可归因于低血氧饱和度或存在脑动静脉畸形。患者家族中没有遗传性出血性毛细血管扩张症的病史。此外，尽管大多数遗传性出血性毛细血管扩张症患者因此患有肺动静脉畸形，会有缺铁性贫血的主诉，但与典型的肺动静脉畸形相比，我们的患者相反患有红细胞增多症。这可以解释为低氧条件下的代偿机制。此外，患者没有咯血或鼻出血的主诉，其表现与典型的肺动静脉畸形不同。
