Ateriovenous subclavia-shunt for head and neck reconstruction

THE DESIGN OF THE ARTERIOVENOUS VASCULAR LOOP DOES NOT AFFECT ITS PATENCY: EXPERIMENTAL STUDY

OBJECTIVE

To evaluate the effect of the design of a femoral vascular loop with anastomosis in the femoral artery of rabbits on the presence of flow (patency) after seven days.

METHODS

A total of 39 rabbits underwent arteriovenous microanastomosis using the microsurgical technique. Two loop designs were used: one circular and the other angled. The parameters evaluated were presence or absence of flow, signs of hemolysis and hemodynamic changes.

RESULTS

After seven days, flow was present in 68% of the angled loops and 75% of the circular loops (p > 0.05). There was a significant intragroup decrease in pCO₂ and a significant increase in pH. For the other parameters evaluated, no significant differences between the two loop models were found.

CONCLUSIONS

A reproducible vascular loop model was shown. There was no significant difference between the two vascular loop models about the presence of flow after seven days. Level of Evidence V, Animal experimental study.

Arteriovenous fistulas for microvascular head and neck reconstruction

BACKGROUND

In head and neck cancer patients, multiple surgeries and radiation can leave the neck depleted of recipient vessels appropriate for microvascular reconstruction. The creation of temporary arteriovenous fistulas using venous interposition for subsequent microvascular reconstruction has rarely been reported in the head and neck. The authors report the largest series of temporary arteriovenous loops for head and neck reconstruction in vessel-depleted necks.

METHODS

The authors performed a case series of major head and neck reconstructions using temporary arteriovenous fistulas with a saphenous vein graft. A subclavian surgical approach was used. All reconstructions were performed at least two weeks after the creation of the initial fistula.

RESULTS

The authors have performed nine reconstructive cases for malignancy using five different free flaps. The subclavian and transerve cervical arteries were used, and the subclavian, internal jugular and cephalic veins were used for microanastomosis. Two cases of flap hematoma and one case of venous pedicle compression were recorded. No cases of flap failure were reported.

CONCLUSIONS

Reconstruction using temporary arteriovenous fistulas is a reliable technique that can be used in the vessel-depleted neck, with excellent outcomes in experienced hands.

Arteriovenous fistulas for microvascular head and neck reconstruction

Background

In head and neck cancer patients, multiple surgeries and radiation can leave the neck depleted of recipient vessels appropriate for microvascular reconstruction. The creation of temporary arteriovenous fistulas using venous interposition for subsequent microvascular reconstruction has rarely been reported in the head and neck. The authors report the largest series of temporary arteriovenous loops for head and neck reconstruction in vessel-depleted necks.

Methods

The authors performed a case series of major head and neck reconstructions using temporary arteriovenous fistulas with a saphenous vein graft. A subclavian surgical approach was used. All reconstructions were performed at least two weeks after the creation of the initial fistula.

Results

The authors have performed nine reconstructive cases for malignancy using five different free flaps. The subclavian and transerve cervical arteries were used, and the subclavian, internal jugular and cephalic veins were used for microanastomosis. Two cases of flap hematoma and one case of venous pedicle compression were recorded. No cases of flap failure were reported.

Conclusions

Reconstruction using temporary arteriovenous fistulas is a reliable technique that can be used in the vessel-depleted neck, with excellent outcomes in experienced hands.

A reappraisal of saphenous vein grafting

Autologous saphenous vein grafting has been broadly used as a bypass conduit, interposition graft, and patch graft in a variety of operations in cardiac, thoracic, neurovascular, general vascular, vascular access, and urology surgeries, since they are superior to prosthetic veins. Modified saphenous vein grafts (SVG), including spiral and cylindrical grafts, and vein cuffs or patches, are employed in vascular revascularization to satisfy the large size of the receipt vessels or to obtain a better patency. A loop SVG helps flap survival in a muscle flap transfer in plastic and reconstructive surgery. For dialysis or transfusion purposes, a straight or loop arteriovenous fistula created in the forearm or the thigh with an SVG has acceptable patency. The saphenous vein has even been used as a stent cover to minimize the potential complications of standard angioplasty technique. However, the use of saphenous vein grafting is now largely diminished in treating cerebrovascular disorders, superior vena cava syndrome, and visceral revascularization due to the introduction of angioplasty and stenting techniques. The SVG remains the preferable biomaterial in coronary artery bypass, coronary osteoplasty, free flap transfer, and surgical treatment of Peyronie disease. Implications associated with saphenous vein grafting in vascular access surgery for the purpose of dialysis and chemotherapy are considerable. Vascular cuffs and patches have been developed as an important and effective means of enhancing the patency rates of the grafts by linking the synthetic material to the receipt vessel. In addition, saphenous veins can be a cell source for tissue engineering. We review the versatile roles that saphenous vein grafting has played as well as its current status in therapy.