Gunshot Wound to the Right Superior Pulmonary Vein With Bullet Embolization to the Aortic Bifurcation: Emergent Surgical Repair

Bullet embolization is a rare complication of gunshot wound injuries with most of the literature consisting of case reports. We report a case regarding bullet embolization to the distal aorta following entry into the right superior pulmonary vein as a result of a gunshot wound to the posterior chest. The patient presented with signs of lower extremity ischemia. Imaging revealed an intrabdominal bullet at the level of L4 and laparatomy identified the bullet to be within the aorta at the bifurcation. Successful repair of the cardiac injury and removal of the intra-aortic bullet were achieved by sternotomy and laparatomy.

Topographic location and branching pattern of the superior mesenteric artery with its clinical relevance: a cadaveric study

BACKGROUND

The topographic location of the superior mesenteric artery (SMA) and its branching pattern are usually arbitrary in textbooks. This study, therefore, aims to provide topographic information of SMA with reference to the vertebral bodies, ventral branches of aorta and branching pattern of SMA.

MATERIALS AND METHODS

The study was conducted on 35 embalmed adult human cadavers. We performed detailed dissection of the SMA to topographically locate its origin in respect to vertebral level and other ventral branches of the abdominal aorta. We have categorised the branching pattern of SMA into three different types depending upon the number of arterial pedicles, traced from proximal to distal to look into their anastomoses and formation marginal artery of Drummond.

RESULTS

Vertebral level of origin of SMA varied between the lower third of twelfth thoracic vertebra (T12) to lower third of first lumbar vertebra(L1), most commonly arose at the level of the lower third of L1(77.14%). The average distances between the origin of SMA and celiac trunk (CT), inferior mesenteric artery (IMA) and aortic bifurcation were 1.84 cm, 6.67 cm and 10.39 cm respectively. Depending on the branching pattern, type A was found in 29 (82.85%) cases, type B in 5 (14.28%) and type C in one (2.85%). In two cases (both of type B), the marginal artery was incomplete.

CONCLUSIONS

The most common topography of origin of the SMA was opposite the lower third of L1. The celiac-superior mesenteric relationship was most consistent than between any other two points on the abdominal aorta; 85% of the SMAs were concentrated within a space of 1.00 cm (0.60-1.50 cm) from the CT. Type A branching pattern was most commonly seen in our study population.

The Viabahn balloon expandable stent for endovascular reconstruction of the infrarenal aorta and its bifurcation in cases of severe obstructive disease

INTRODUCTION

The covered endovascular reconstruction of the aortic bifurcation (CERAB) represents a promising technique for the treatment obstructive lesions involving the aortic bifurcation. The aim of this report is to describe the use of a new generation balloon-expandable stent-graft (Viabahn VBX, W.L. Gore&Associates, AZ, USA), in the CERAB configuration for the treatment of aorto-iliac obstructive lesions involving the infrarenal aorta and bifurcation.Technical note: This technique was adopted in two patients with severe aorto-iliac obstructive lesions. After bilateral iliac recanalization, an 11 mm diameter VBX stent was deployed in the infrarenal aorta; a post-dilatation up to 16 mm with a non-compliant balloon was performed to adapt the proximal edge of the stent to the aortic diameter. Two 8 mm diameter VBX stents were then deployed at the aortic bifurcation in a kissing conformation, overlapping with the previously positioned aortic stent for 15 mm. A post-ballooning with two kissing 12 × 20 mm compliant balloons (Powerflex Pro PTA, Cordis, CA, USA) was performed to adapt the parallel stents to the aortic cuff. A post-operative angio-CT demonstrated optimal conformability of the aortic cuff to the aortic wall, and apposition of the kissing stents to the aortic cuff.

CONCLUSIONS

This preliminary experience shows that the VBX stent may allow an effective reconstruction of the aortic bifurcation; the conformability and flaring capability may allow to overcome the diameter mismatch between the aorta and the iliac arteries.

Meta-analysis of Individual Patient Data After Kissing Stent Treatment for Aortoiliac Occlusive Disease

PURPOSE

To evaluate short- and long-term technical and clinical outcomes after kissing stent treatment of aortoiliac occlusive disease (AIOD) based on an individual participant data (IPD) meta-analysis.

MATERIALS AND METHODS

A search of the Scopus database identified 156 articles on KS treatment of AIOD; of these 22 met the inclusion criteria. Authors of 19 articles with contact information were approached to join an IPD consortium. Eight author groups responded and 5 provided anonymized data for merging into an IPD database. The number of included procedures was equal before and after 2005. The primary study outcome was the cumulative patency at 24 months. Secondary outcomes were patency at up to 60 months, complications, and changes in Rutherford category and ankle-brachial index. The predictive value of stent protrusion length, pre-/postdilation, stent type, and patient demographics on primary patency were examined with Cox proportional hazard modeling; outcomes are reported as the hazard ratio (HR). The Kaplan-Meier method was employed to estimate patency rates.

RESULTS

In total, 605 (40.9%) of 1480 patients presented in the literature were included in the IPD analysis. The indication for intervention was intermittent claudication in 84.2% and critical limb ischemia in 15.8%. Lesions were classified as TransAtlantic Inter-Society Consensus (TASC) A or B in 52.8% and TASC C and D in 47.2%. The overall primary patency estimate was 81% at 24 months. Primary patency significantly increased after 2005 (p=0.005). Cox regression analysis revealed only age as a significant predictor of sustained primary patency (HR 0.60, p<0.005). Any previous endovascular intervention (HR 2.52, p=0.02) was the main predictor for loss of secondary patency; history of cardiovascular disease (HR 0.27, p=0.04) was the main predictor of sustained secondary patency.

CONCLUSION

The kissing stent technique has a good safety profile and acceptable patency rates up to 2 years, even in TASC C and D lesions, supporting an endovascular-first approach for AIOD.

Influence of Iliac Stenotic Lesions on Blood Flow Patterns Near a Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) Stent Configuration

PURPOSE

To investigate the effect of distal stenotic lesions on flow patterns near a covered endovascular reconstruction of the aortic bifurcation (CERAB) configuration used in the treatment of aortoiliac occlusive disease.

METHOD

Laser particle image velocimetry measurements were performed using in vitro models of the aortic bifurcation with and without a CERAB configuration in place. A hemodynamically nonsignificant stenosis (ΔP: 9 mm Hg), a hemodynamically significant (ΔP: 26 mm Hg) stenosis, and a total occlusion were simulated in the left iliac arteries. Velocity fields and time-averaged wall shear stress (TAWSS) were calculated.

RESULTS

Hemodynamically significant distal lesions did not influence the inflow patterns or TAWSS (0.5-0.6 Pa) in either model. However, hemodynamically significant distal stenotic lesions caused a 2-fold decrease in peak outflow velocities (control: 106 vs 56 cm/s, CERAB: 96 vs 54 cm/s) and a 3-fold decrease in TAWSS (control: 1.34 vs 0.44 Pa, CERAB: 0.75 vs 0.21 Pa). There was a 2-fold decrease in wall shear stress in the CERAB outflow compared with the control, independent of lesion severity.

CONCLUSION

In the CERAB technique, adequate distal runoff is identified as an important parameter to ensure patency. This in vitro study showed that distal stenotic lesions influence aortic bifurcation outflow patterns and TAWSS more extensively in the CERAB configuration. Distal stenotic lesions could therefore increase the risk of disease progression and loss of stent patency. In vivo studies are necessary to confirm these observations.

Initial Experience With Covered Endovascular Reconstruction of the Aortic Bifurcation in Conjunction With Chimney Grafts

PURPOSE

To show feasibility of the covered endovascular repair of the aortic bifurcation (CERAB) technique in conjunction with chimney grafts in aortic side branches for complex aortoiliac occlusive disease.

METHODS

Two European centers and one facility located in New Zealand participated in a retrospective observational study that enrolled 14 consecutive patients (mean age 61.2±8.9 years; 11 men) treated with CERAB in conjunction with chimney graft(s) between December 2012 and May 2015. Indications for treatment included disabling claudication in 9 and critical limb ischemia in 5. Lesions were classified as TransAtlantic Inter-Society Consensus II B (n=1), C (n=1), or D (n=12).

RESULTS

A total of 15 chimney grafts were used to perfuse the inferior mesenteric artery (n=8), the right renal artery (n=4), and the left renal artery (n=3). Technical success was achieved in all cases. Procedural complications included 5 unintended dissections and 1 vessel thrombosis, all of which were successfully treated intraoperatively. Five patients developed access-site hematoma/ecchymosis (3 at the brachial access). Mean follow-up was 12 months (range 6-24) without death or loss to follow-up. One patient suffered occlusion of a CERAB limb and an IMA chimney graft; the former was recanalized, but the IMA graft was not; there were no signs of bowel ischemia. Ankle-brachial indices significantly increased from 0.54 (range 0.47-0.60) preoperatively to 0.97 (range 0.90-1.00) in 11 patients examined at 12 months, and all patients had an improvement in the Rutherford category. All CERAB limbs, including the one recanalized, were patent at the most recent follow-up, as were 14 of 15 chimney grafts.

CONCLUSION

Chimney-CERAB is technically feasible and may offer an alternative to open surgery for complex aortoiliac occlusive disease. Further prospective studies are needed to confirm these findings.

Pelvic nodal CTV from L4-L5 or aortic bifurcation? An audit of the patterns of regional failures in cervical cancer patients treated with pelvic radiotherapy

OBJECTIVE

To assess the patterns of recurrence in cervical cancer patients treated with pelvic nodal clinical target volume at L4-L5 junction instead of aortic bifurcation.

METHODS

Records of patients with locally advanced cervical cancer treated with chemo-radiation were reviewed. Patients treated with standard pelvic fields (superior border of the field at L4/L5 junction), without any radiological evidence of regional lymphadenopathy (<10 mm) were included in the study. The level of aortic bifurcation was retrospectively documented on computed tomography. Patterns of recurrences were correlated to the aortic bifurcation and the superior border of the radiation fields (L4/L5).

RESULTS

Aortic bifurcation was above the radiation fields (above L4/5) in 82 of 116 (70.7%) patients. Of the nine patients that recurred above the radiation field, 5 (55%) were above L4/5 failures, i.e. between aortic bifurcation and L4/5, and 4 (45%) had para-aortic failures. On retrospective analysis, 16 patients were found to have subcentimeter lymph nodes and higher nodal failures (7/16) were observed in patients with subcentimeter regional lymph nodes at diagnosis.

CONCLUSIONS

Superior border of nodal clinical target volume should ideally include the aortic bifurcation instead of L4-L5 inter space in patients with locally advanced cervical cancer. Radiotherapy fields need to be defined cautiously in patients with subcentimeter pelvic lymph nodes.

Anatomical variations in the aortic bifurcation in new zealand white rabbits on arteriography

The radiologic anatomy of the aortic bifurcation in the rabbit has received little study but it is important as this anatomical area is widely used in atherosclerosis research. Thirty rabbits were used to study the aortic bifurcation and subsequent branching patterns on arteriography. Fifteen different arteries were identified. Mean arterial diameters of 2.88 ± 0.7 and 2.27 ± 0.55 mm were obtained for the aorta and external iliac arteries, respectively. The cranial and middle aspects at the seventh lumbar vertebra (L7) were the most frequent anatomical landmarks (53.3% of the cases) for aortic and common iliac bifurcations, respectively. The caudal aspect of L6 was the most frequent origin (50% of the cases) for the median sacral artery. Deep circumflex iliac arteries originated from common iliac arteries and not the abdominal aorta in the rabbit, showing anatomical asymmetry in 73.3% of the cases. No gender disparity was found in the anatomical location of any of the arteries of the study. Knowledge of normal vascular landmarks for the aortic bifurcation as well as anatomical variations should be helpful to future experimental studies.