Ann Thorac Surg 2006;82:725-726
© 2006 The Society of Thoracic Surgeons
Case report
Spontaneous Dissection of an Anomalous Systemic Artery in the Lung During Pregnancy: A Rare Cause of Hemoptysis
Shafaque Shaikh, MRCSEDa,*,
Rasheed A. Saad, MRCSEDa,
Gordon Christie, MRCP, PhDb,
Keith M. Kerr, FRCPathc,
Hardy Remmen, MDa
a Department of Cardiothoracic Surgery, Aberdeen Royal Infirmary, Aberdeen, United Kingdom
b Department of Respiratory Medicine, Aberdeen Royal Infirmary, Aberdeen, United Kingdom
c Department of Clinical Pathology, Aberdeen Royal Infirmary, Aberdeen, United Kingdom
Accepted for publication November 8, 2005.
* Address correspondence to Dr Shaikh, 4 Raeden Park Rd, Aberdeen, United Kingdom AB15 5LQ. (Email: drshafaque{at}yahoo.co.in).
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Abstract
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We report a rare case of spontaneous dissection of an anomalous systemic artery supplying a normal basal segment of the right lung during pregnancy, leading to recurrent hemoptysis. This article aims to discuss the clinical presentation, diagnostic curiosity, management using a minimally invasive technique (video-assisted thoracoscopic lobectomy), and finally the histopathologic findings.
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Introduction
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Abnormal systemic arterial supply to normal lung segments is a relatively rare congenital anomaly of the pulmonary blood supply [1]. As with pulmonary sequestration, the aberrant vessel usually arises from the abdominal aorta and frequently involves the left lower lobe [2]. This anomaly is one of the lesions described as part of the sequestration complex, and is sometimes classified as a pseudo-sequestration rather than a true pulmonary sequestration [3].
This vascular anomaly is often asymptomatic, but may lead to pulmonary hypertension due to longstanding shunt, giving rise to symptoms such as cough, hemoptysis, and dyspnea. These may lead to left ventricular enlargement and congestive cardiac failure [4].
A 29-year-old woman of African origin presented at 20 weeks of gestation with a 10-day history of hemoptysis and mild central chest pain after a long-haul flight. Initial investigations including chest roentgenogram and electrocardiograph were unremarkable. Color Doppler ultrasound scan of the lower limbs showed no evidence of deep vein thrombosis. A subsequent ventilation and perfusion scan reported a low probability of pulmonary thromboembolism. No obvious lesions were noted on bronchoscopy. Bronchial angiogram performed for continuing fresh bright red hemoptysis was also normal. Contrast enhanced computed tomographic scan revealed an abnormal area of consolidation in the medial aspect of the right lower lobe (Fig 1) with an anomalous artery arising from the abdominal aorta. A radiologic diagnosis of a sequestrated pulmonary segment with an anomalous systemic artery was made. She responded to conservative treatment and remained stable throughout her pregnancy. After her elective caesarean section, video-assisted thoracoscopic surgery showed an anomalous vessel to the right lower basal segment of the lung along with areas of hemorrhage. A video-assisted thoracoscopic surgery right lower lobectomy was performed. She had an uneventful recovery and was discharged from hospital on the fourth post-operative day. Histopathology revealed dissection of the anomalous vessel with a dissection tract close to the adventitia and clear evidence of both old and recent alveolar hemorrhage (Fig 2A). Interstitial hemorrhage around some vessels and in the pleura signalled pulmonary hemorrhage at high (systemic) pressure. The underlying pulmonary parenchyma was otherwise unremarkable with none of the usual fibro-inflammatory changes associated with pulmonary sequestration. She remains asymptomatic after follow-up of 6 months.
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Fig 1. Chest computed tomographic scan showing consolidation of right lower lobe surrounding abnormal vessel.
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Fig 2. (A) Hematoxylin and eosin stained section in the region of dissecting artery. (B) The elastic van Gieson stain clearly demonstrates the split between the elastic media and adventitia.
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Comment
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Vascular dissections occur rarely during pregnancy. There are several reports of dissection of the aorta, renal, splenic, coronary, and cerebral arteries during pregnancy, the predisposing factors being arterial intimal hyperplasia, reorganization of the media due to hormonal changes and altered hemodynamics [5]. In the present case, the pattern of interstitial pulmonary hemorrhage (Fig 2B) is suggestive of bleeding from a high-pressure system; a classical feature of dissection. There were no major or minor traumatic events such as violent coughing, sneezing, or vomiting identified in our patient. However, she had a long-haul flight prior to her clinical presentation; whether this influenced the occurrence of the dissection remains unknown.
Radiologic investigations are essential in confirming clinical suspicions of this condition. The chest roentgenogram is invariably normal. Occasionally a vessel-like opacity in the lower lung field, possibly behind the heart, with focal obliteration of the descending aortic interface can be seen. A computed tomographic scan remains the investigation of choice. It can demonstrate the anomalous systemic artery, absence of pulmonary arterial supply, and normal bronchial system in the affected segments [6]. In the present case, a radiologic diagnosis of a sequestrated pulmonary segment was made based on computed tomographic scan findings. The subsequent correlation with histopathology confirmed that the lung consolidation was due to recurrent alveolar and interstitial hemorrhage, and not actual pulmonary sequestration.
The management of these cases, especially in the presence of pregnancy, remains a real challenge. The adverse effects of radiation on the fetus and the risk of surgery on the continuation of pregnancy make decisions difficult. Achieving the correct risk-benefit balance in such cases requires a multidisciplinary approach. The risk of re-dissection is also an important consideration, potentially triggered by the strain of coughing and expulsive efforts of labor. This necessitates close observation in a tertiary care hospital as was done in this case.
With significant advancements in video-surgery, digital technology, instrumentations, and surgical expertise, video-assisted thoracoscopic surgery can be offered to these patients. This technique has an established role in the diagnosis and treatment of intrathoracic lesions. Although challenging in the presence of anomalous anatomy, this procedure is still effective and safe in the hands of experienced thoracic surgeons. There are significant advantages, such as less pain and scarring, shorter hospital stay and, in many cases, early return to work as compared with open surgical procedures.
In conclusion, this case highlights a rare cause of recurrent hemoptysis with diagnostic and treatment challenges. With the availability of minimally invasive surgical techniques, this could be managed without the associated morbidity of conventional thoracotomy.
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References
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Abstract
Introduction
