Microsurgical repair of neonatal iliac artery injuries with saphenous vein grafts

1 Background

Cardiac catheterization has become a common treatment modality for children with heart disease; however, vascular injury is common [1–3]. Treatment algorithms for limb ischemia in infants include heparinization, surgical intervention, or both [4]. Past reports [5–8] describe surgical treatment of catheter-related injuries in neonates. Here we present two additional cases in which saphenous vein grafts are used to repair iliac artery avulsions in neonates.

2 Case reports

2.1 Case 1

Patient 1 was a 35 weeks gestational age female weighing 3.4 kg, with transposition of the great arteries. On day-of-life 1, a balloon atrial septostomy was performed to correct hypoxemia. The right iliac artery was inadvertently cannulated, and tissue was adherent to the sheath upon removal. The septostomy was completed through the left femoral vein; however, the patient developed a right flank hematoma and became hypothermic and bradycardic. She had a cool, mottled right leg with poor turgor (Fig. 1), and lacked distal and femoral artery Doppler signals.

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Fig.1.

Upon consultation, the patient’s right lower extremity was mottled, cool, with poor turgor, and lacked Doppler signals.

An extended laparotomy incision was used to expose the common iliac artery, and the external iliac artery was found to be avulsed. The common femoral artery was retracted in the thigh. We harvested the ipsilateral greater saphenous vein and administered systemic heparin. At this point, the patient’s hemodynamics were improving. Using an operating microscope, we interposed the six cm reversed graft (end-to-side to the common iliac artery and end-to-end to the common femoral artery), with a maximum lumen diameter of 1.5 mm (Fig. 2). The patient’s right foot became pink, and Doppler signals returned. Lower leg and foot fasciotomies were performed due to prolonged ischemia time (Fig. 3). She returned to the unit on an epinephrine drip and was kept hypothermic for 24 hours for neuroprotection. She underwent staged abdominal closure, and an arterial switch procedure was performed weeks later. Now three years old, she is advancing cognitively and is able to walk and run. She has a 0.3 cm and 0.2 cm leg length discrepancy of the tibia and femur respectively.

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Fig.2.

The 6-cm greater saphenous vein interposition graft, with anastomoses to the common iliac artery and the common femoral artery.

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Fig.3.

At the conclusion of the procedure, the foot was reperfused and pink, with Doppler signals at the femoral and popliteal arteries. A silastic patch was used for temporary abdominal closure. Leg and foot fasciotomies were performed due to prolonged ischemia.

2.2 Case 2

Patient 2 was a 32 weeks gestational age female with aortic coarctation, 16p11.2 microdeletion, and Grade I intraventricular hemorrhage. On day-of-life 31, left heart catheterization with angioplasty was performed for transverse aortic arch stenosis. At the end of the procedure, the sheath was resistant to removal from the right femoral artery, and the leg was pulseless and pale. Doppler signal was detectable only at the femoral artery. Pallor progressed to mottling (Fig. 4), and the patient was taken emergently to the operating room.

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Fig.4.

Pre-operatively, the patient’s right lower extremity was mottled, cool, and without Doppler signals. The left leg was well perfused.

After retroperitoneal exposure, external iliac avulsion from the common iliac artery was identified. Under an operating microscope, a 2.5 cm ipsilateral reversed saphenous vein graft was interposed (end-to-side to the common iliac artery and end-to-end to the common femoral artery), with a maximum lumen diameter of 2.0 mm. Shortly after, the distal anastomosis clotted and was revised. The leg became pink to the upper tibial level. Right lower leg fasciotomies were performed, and systemic heparinization was initiated.

The patient required an epinephrine drip. Her foot remained white. Two days later the patient underwent right foot fasciotomies. Ischemic demarcation occurred distally to the level of the metatarsals, and the patient later underwent a transmetatarsal amputation eight days after revascularization. She gained right foot sensation based on withdrawal to cool temperatures and dorsiflexion by 3 months of age. At 16 months old, she was able to crawl and cruise. She is followed for a 2-cm and 0.8-cm leg length discrepancy of the tibia and femur respectively

Peripheral vascular injuries in children younger than 5 are most commonly iatrogenic [1]. Pediatric catheterization has a complication rate as high as 9% [2, 3], and vascular complications occur more frequently in patients younger than six months [2, 3].

For infants with non-limb-threatening ischemia, heparin and thrombolytics have been advocated, especially given infants’ ability to establish collateral circulation. Furthermore, revascularization in this patient population has historically poor surgical outcomes [9]. General guidelines promote systemic heparin if the patient lacks pulses after catheterization and clinical ischemia is present, with exploration if no improvement in 6 to 8 hours [4]. In limbs with signs of critical ischemia not responding to anticoagulation, operative management is commonly accepted [9]. Signs of critical ischemia include pallor, pain, lack of turgor, absence of capillary refill, loss of pulses or Doppler signal. If these signs do not improve or resolve within an hour or two after initiation of thrombolytic therapy or anticoagulation, then operative intervention should be pursued to avoid irreversible soft tissue loss. Direct arterial repair has superior outcomes to thrombectomy and angioplasty [1]. In our cases, reverse saphenous vein grafts were a necessary alternative.

A few reports of similar injuries and surgeries exist. Kay [5] describes a neonate who had iliac artery avulsion. Vein graft reconstruction was performed; however, the anastomosis occluded twice with improved clinical status after thrombolysis. Devaraj [6] reports a neonate who had avulsion of the common iliac artery. This was reconstructed with a vein graft and also occluded, improving clinically with thrombolysis. Vanmaele [7] describes a 1-day-old whose superficial femoral artery was transected during venous cutdown. A vein graft was interposed and occluded days later, but the patient did well clinically. Clugston [8] performed a vein graft from the popliteal artery to the posterior tibial artery in an infant following a crush; thrombectomy and leech therapy were also used.

Case 1 is the youngest patient to have a successful vein graft reconstruction of her external iliac artery, with an excellent outcome. The graft stayed patent throughout admission despite a narrow lumen, hypothermia, and prolonged vasopressor therapy. This supports microsurgical repair of arterial injuries in the youngest, sickest patients.

Case 2 cannot be considered an outright success given the transmetatarsal amputation. Nonetheless, it identifies challenges of emergent microvascular surgery in a neonate. The anastomoses were small, and the common femoral artery had vasospasm and clot. Post-operative use of vasopressors may have further diminished perfusion to her foot. Finally, ischemia may have been irreversible at the distal foot at the end of the nine-hour case. Immediate foot fasciotomies may have been helpful. She has limb length discrepancy, a known sequela of vascular compromise after catheterization [4]. The favorable aspects of care for this patient of the case included early diagnosis and intervention, preservation of limb length, and avoidance of inevitable ischemic compromise to the gluteal musculature that may have led to rhabdomyolysis and its sequelae.

4 Conclusion

These cases highlight the importance of early diagnosis and treatment of ischemic limbs regardless of patient size or age, and the importance of long-term follow-up with monitoring for limb-length discrepancies. In our cases, microsurgery was limb-saving and perhaps even life-saving.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.