ABLL has previously been classified as Pryce’s type I pulmonary sequestration, but has become recognized as a pulmonary vessel malformation that is different from pulmonary sequestration [6]. Most previously reported cases describe aberrant arteries arising from the descending aorta; reports of ABLL in which the aberrant artery arises from the celiac artery, as in the present case, are relatively rare (6%) [7]. The median diameter of the aberrant artery has been reported to be 10.0 mm (range 4.0–20.0 mm); the aberrant artery in our case is the larger than past reports [7]. This meant that a two-staged approach was required in the present case, in contrast to the methods reported in other studies.
Surgical resection of the aberrant artery and ipsilateral lobectomy are generally performed for patients with ABLL, and embolization is indicated for inoperable cases [8]. Recently, certain studies have reported the division of blood flow from an aberrant artery without pulmonary resection with an uneventful postoperative course [9, 10]. In the present case, given the large diameter of the aberrant artery, we considered that preoperative reduction of blood flow of the aberrant artery by embolization was a safe approach to prevent unexpected intraoperative bleeding. However, coil embolization is not recommended in cases where the inner vessel diameter is 10 mm or greater because of the risk of incomplete occlusion and coil migration [11]. Even though embolization for a narrow segment of the aberrant artery was an option, we prioritized shutting down the abnormal blood flow of the pulmonary arteriovenous fistula; therefore, we first performed surgical resection of the aberrant artery and left lower lobectomy prior to coil embolization for the remnant aberrant artery as a staged procedure. There is one report of successful embolization of an aberrant artery in an operable patient [12]; however, no other case studies have performed combined operative procedures with resection of the aberrant artery and subsequent coil embolization for remnant flow, partly because the aberrant artery is too large and partly because there might be a possibility of concomitant pulmonary arteriovenous fistula. Although we performed an unprecedented staged operation, it might be a feasible procedure in such cases, and as a result, the postoperative course was uneventful.
With regard to surgical procedures, it has been reported that the resection of aberrant arteries using an endoscopic stapler is a safe procedure, which we performed the same way [5]. Before surgery, we were concerned about using an endoscopic stapler for the aneurysmal aberrant artery; however, intraoperatively, we confirmed that the artery wall was thick and firm; therefore, we resected it using an endostapler. Furthermore, the diameter of the patient’s aberrant artery was the same as the descending aorta, which was larger than the previously reported diameters. Thus, we reinforced the stump using Teflon pledgets without any complications [7]. During the surgery, a resection of the left lower pulmonary vein was performed first because the presence of preoperative pulmonary arteriovenous fistula was possible; however, as a result of rapid congestion of the left lower lobe, it was considered that the resection of the aberrant artery prior to pulmonary vein might be desirable to prevent ipsilateral pulmonary congestion. The good outcome of this case indicates that the optimal surgical strategy for variable ABLL should be considered and decided depending on each case.
Considering the histopathological features of the aberrant artery, the presence of an elastic artery with dissection of the tunica media might be complicated when an aneurysm forms with high blood flow, which is the same as our case. Indeed, there are several reports of aneurysms of aberrant arteries leading to fatal ruptures [2, 3]. Giant aberrant arteries like that of the present case carry the risk of dissection and rupture; therefore, appropriate treatment must be carried out in a timely manner following diagnosis.