Pulmonary sequestration is a congenital lung malformation lacking respiratory function and supplied by systemic circulation, most commonly from the descending aorta and celiac trunk. The cause of these malformations remains unknown but likely involves abnormal budding of the developing lungs [3]. Identification of pulmonary sequestrations can usually be done by diagnostic imaging showing a soft tissue mass with a non-pulmonary feeding vessel. Postnatally, pulmonary sequestrations may be asymptomatic or present with dyspnea, cyanosis, chronic cough, wheezing, and recurrent pneumonia. Overall, sequestrations are generally considered for resection given the potential for infections [2] and confusion with malignant lesions [4]. Though extralobar sequestrations are much less prone to infectious complications because of their distinct pleura and systemic venous drainage [5], it is still recommended to remove asymptomatic EPS lesions to avoid infection and possible subsequent pneumonitis. Minimally invasive surgical techniques improve cosmetic outcomes and decrease recovery time for these patients.

Extralobar cases account for 25% of pulmonary sequestrations and rarely present below the diaphragm, with up to 15% being subdiaphragmatic [4, 5]. Even more rare are intradiaphragmatic extralobar pulmonary sequestrations (IDEPS). These are proposed to arise from an accessory bud forming at the level of the diaphragm with subsequent embryological fusion of the diaphragm enclosing the EPS within its musculature [4].

Contrast-enhanced CT is the gold standard for investigating the anatomy and arterial supply of pulmonary sequestrations prior to surgical resection [6]. However, as in the present case, it may be unclear from preoperative imaging, including CTA, where the EPS is anatomically located in relation to the diaphragm. Preoperative identification of true intradiaphragmatic sequestration is especially challenging with subsequent difficulty in the selection of the best surgical approach [7].

Kargl et al. sought to categorize the arterial blood supply for 21 cases of PS and CPAM as supradiaphragmatic, subdiaphragmatic, or both. Subdiaphragmatic blood supply was categorized into those arising off the abdominal aorta and celiac trunk, with all except one of these cases representing extralobar pulmonary sequestrations [8]. The majority of EPS lesions are therefore supplied by subdiaphragmatic vessels, regardless of the EPS itself being above or below the diaphragm. Therefore, the location of extralobar pulmonary sequestrations should not be entirely assumed based on its arterial supply.

Due to the rarity of IDEPS, there is limited literature regarding their diagnostic workup and management, and controversy continues to exist on whether a thoracic or abdominal surgical approach should be taken. In their case series, Nijagal et al. agreed that preoperative imaging studies may provide discordant results on the locations of EPS [9]. They recommended that preoperative planning include preparation for a combined thoracoscopic and laparoscopic approach with subsequent removal of the mass using the approach that provides superior visualization [9]. Oreglio et al. noted that, although arterial supply originated from the celiac trunk in their cases, approaching via the thoracic cavity was still preferred for its increased visualization and feasibility in reaching the IDEPS [10]. However, a potential risk of using a thoracic approach is retraction of the feeding vessel into the abdominal cavity resulting in intra-abdominal bleeding that may be missed [10]. There are advantages and disadvantages of both thoracoscopic and laparoscopic approaches and a combined thoracoscopic-laparoscopic approach may be preferred for its superior visualization.