Introduction

Pararenal aneurysms of the abdominal aorta can be treated endovascularly by fenestrated endovascular aortic repair (FEVAR) [1] with the implantation of a custom-made device (CMD). The main limitation of such CMDs is the lead time: it can take up to approximately 3 months from decision to operation (depending on the need for special design and manufacturer), increasing the risk for aneurysm-related complications during this period [2]. Several approaches exist to overcome this limitation including the off-label use of off-the-shelf branched devices, parallel grafts, in situ fenestrations and physician-modified endografts (PMEGs). Although these procedures are technically demanding, a rapid progression regarding the number of aortic centers using PMEGs can be observed [3], especially since the early and mid-term results are promising.

We report a case of an asymptomatic pararenal aneurysm that was treated with a 4-vessel fenestrated PMEG. Using a PMEG instead of an off-the-shelf branched endograft, a relatively shorter proximal landing zone could be achieved which enabled us to preserve the Adamkiewicz artery, which was detected on computed tomography angiography (CTA) images [3].

Case presentation

A 75-year-old male with a history of chronic obstructive pulmonary disease, coronary artery disease and umbilical hernia repair was admitted to a tertiary aortic center with a large aortic aneurysm detected incidentally on abdominal ultrasound (US). CTA confirmed an 88 mm pararenal aortic aneurysm with no sign of imminent rupture. A large Adamkiewicz artery was detected originating from the left 9th intercostal artery (Fig. 1A). Ectatic (41 mm) supraceliac aortic segment, median arcuate ligament compression of the celiac artery and severe tortuosity of the common iliac arteries made an endovascular repair challenging (Fig. 1B and C). The patient was unfit for open surgical repair based on the anesthesiologist. The ostium of the Adamkiewicz artery should have been covered during an off-the-shelf branched endovascular aortic repair (BEVAR). We have refrained from using an off the shelf branched graft as the necessary proximal extension would have covered the ostium of the Adamkiewicz artery, thus CMD and PMEG repair was considered by our aortic team. The patient preferred expedited PMEG repair over waiting for a CMD.

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Perioperative imaging. A: Curved planar reformation of the great radicular artery of Adamkiewicz, originating from the left 9th intercostal artery (asterisk). Note the characteristic anastomosis (arrow) with the anterior spinal artery (arrowheads). B: Curved planar reformation of the aortic lumen. Note the compression of the celiac trunk (arrow) and the posterior bulge of the paravisceral aorta (arrowheads). C: Volume rendering of the paravisceral aneurysm showing the mural thrombus (asterisk). D: Selective angiography of the left 9th intercostal artery, filling a great radicular artery of Adamkiewicz (arrowheads). E: Fluoroscopy image during the positioning of the physician-modified endograft (asterisks) inserted via the contralateral gate (arrow) of the partially deployed abdominal endograft (arrowheads). F: Fluoroscopy image of the flaring maneuver of the right renal bridging stent. Note the indentation on the flaring balloon that was inflated exceeding nominal pressure (arrowheads) and the yet unstented celiac fenestration with the four markers of the Hungaroring (asterisk). E: Follow-up CT angiography with dynamic protocol to exclude endoleak after 6 months

Citation: Imaging 2024; 10.1556/1647.2024.00227

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To achieve sealing in the ectatic supra-celiac landing zone a thoracic device (45 × 150 mm Valiant, Medtronic Inc., Dublin, Ireland) was used as a proximal PMEG extension of a standard bifurcated main body (35 mm Excluder, W.L. Gore & Associates, Newark, DE, USA). Prior to insertion, backtable modification of the thoracic prosthesis was performed to create a device with four fenestrations for the celiac, superior mesenteric and renal arteries. Each fenestration was created and reinforced with a Hungaroring as reported earlier [4]. The completed device was then successfully reloaded into the original delivery system, taking extra care to preserve the nose-cone to enable sheathless delivery of the rather large device.

First, Adamkiewicz artery was identified by selective angiography (Fig. 1D). The bifurcation main body was then inserted from the left side, partially opened at the estimated position (Fig. 2). The contralateral gate was cannulated from the right side, through which the PMEG was inserted while maintaining the position of the partially deployed bifurcation from the left (Fig. 1E and F). The PMEG was then positioned at the desired height, after which the main body was released under the ostium of the Adamkiewicz artery completely in a position to maximize overlap between the PMEG and the bifurcation main body. After main body deployment, the PMEG was released at the optimal position taking extra care to avoid craniocaudal or circumferential misalignment of the fenestrations and the visceral ostia. Superior mesenteric and renal arteries were cannulated via transfemoral access. Bridging stents (iCover, iVascular, Barcelona, Spain) were deployed and flared with a flaring balloon (Advance, Cook Medical Inc, Bloomington, IN, USA) above nominal pressure to achieve optimal sealing. The compressed celiac trunk was stented from a brachial access. Technical success was confirmed by completion angiography and cone-beam CT. A contrast volume of 190 mL (Ultravist; Bayer Healthcare, Berlin, Germany) was used during the procedure. The procedure was performed with a fluoroscopy time of 40 min, with a cumulative air kerma of 135 mGy and a dose-area product of 25.25 Gy cm² in a hybrid operating theater equipped with fusion imaging (Discovery; GE Healthcare, Chicago, Illinois, USA).

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Graphic showing the simultaneous deployment technique. A: Partial deployment of the abdominal main body below the right renal artery. B: Introduction of the thoracic component via the contralateral gate of the partially opened abdominal main body. C: Positioning of the thoracic component according to the right renal artery, after full deployment of the abdominal main body. D: Cannulation of the four branches after deployment of the thoracic component. E: Final image with the four bridging stents in place and the aortic components fully deployed

Citation: Imaging 2024; 10.1556/1647.2024.00227

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On-table extubation was performed to check for the symptoms of spinal cord injury to exclude the need of a therapeutic cerebrospinal fluid drainage. After an uneventful postoperative course, the patient was discharged on the 5th day. Follow-up CTA at 6 months showed patent branches and the complete exclusion of the aneurysm without any endoleaks (Fig. 1G and H).

Discussion

There is an ongoing debate over the best practice regarding non-infrarenal aortic aneurysms requiring expedited repair. Currently, multidisciplinary team decisions are usually made on an individual basis and are largely dependent on local expertise [5] and device availability besides anatomical feasibility [6].

Patient specific risk factors can be modified if there is time before the urgent procedure. In our case the patient was at high risk due to his pulmonary and cardiac status, but a short-term medical preparation could lower the perioperative risk of any cardiac or pulmonary event. The renal function can be spared with reducing contrast with the use of fusion imaging [7].

The risks and benefits of utilizing a more proximal sealing zone within the visceral aorta for juxta-/pararenal complex aortic repair needs further investigation, but data suggest a trend towards higher risk of spinal cord ischemia following supraceliac sealing [8]. Beside the careful analysis of the main arteries providing collaterals to the spinal cord blood supply (subclavian, internal iliac arteries), identification of the Adamkiewicz artery – for planning and performing the reconstruction to preserve it – may help to reduce the risk of spinal cord ischemia. CMDs appear to limit the extent of unnecessary aortic coverage and the theoretical subsequent risk of spinal cord ischemia compared to off-the shelf multibranched devices in a recent retrospective study [9].

Although early and mid-term results of the PMEG technique are promising [10], there is a lack of data regarding the long-term outcome of such interventions. Theoretically, PMEG fenestrations without any reinforcement (eg. in situ fenestrations) and fenestrations with non-circular reinforcement (eg. guidewire and snare) have an inherent risk of late degeneration and dilation of the fenestration, leading to disconnection and IIIc endoleak. With the use of the Hungaroring [4], this risk might be eliminated so that we can expect a similar durability of the fenestration as what is seen regarding the fenestrations of company manufactured CMDs.

Conclusion

Using a PMEG for pararenal anatomy may help to achieve a shorter proximal landing zone compared to off-the-shelf branched endografts, which is crucial to lower the risk of spinal cord injury after proper risk assessment and meticulous planning. Closed-ring reinforcement of PMEG fenestrations using the Hungaroring may increase the durability of such repairs, which is supported by the 6 months follow-up CTA scan as well.

Declarations

Authors' contribution: Reviewed the final version of the manuscript and agreed to submit it to IMAGING for publication: C.N.C., Z. S., A.H., E.T., P.O., Z.M. Conceptualization: C.N.C, Z.S.; visualization A.H, C.N.C, roles/writing—original draft Z.M., E.T., P.O., and AH.; writing—review and editing C.N.C, Z.S.

Funding sources

There was no funding involved.

Conflict of interests

The authors have no conflict of interest to disclose.

Ethical statement

The author clarifies that written informed consent was obtained and the anonymity of the patient was ensured. The case report submitted to IMAGING have been conducted in accordance with the Declaration of Helsinki and according to requirements of all applicable local and international standards. Written informed consent was obtained from the patient for publication of this case report and any accompanying images.