Vladimir B. Sidorov, Mark D. Rechter, and Vladimir K. Minachenko
PERIPHERAL ARTERIOVENOUS ANASTOMOSIS: A N ALTERNATIVE TECHNIQUE Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
A FREE FLAP TRANSFER ABSTRACT Prevention of thrombosis in the inflow and outflow vessels of a free flap is a problem of current interest. The method of creating a peripheral arteriovenous anastomosis within a free flap was validated in an experimental study and substantiated in a clinical case. No thrombotic complications were observed in 16 transfers of saphenous fasciocutaneous flaps in a dog model, as well as in an elderly patient with free radial forearm flap transfer to an irradiated foot. Scanning electron microscopy of the venous anastomosis proximal to the arteriovenous fistula revealed the difference of pathologic changes as early as 4 hr following surgery. It is the conclusion of the authors, that performing a distal arteriovenous fistula in a free flap, is an effective procedure for prevention of early occlusion in a proximally anastomosed artery and vein.
Failure of free-flap transfers is usually associated with thrombosis of the microanastomoses. The thrombosis occurs at the venous, as well as at the arterial, site.'- 4 Ligation of the anastomosed artery at the periphery of the flap leads to a dramatic change of blood flow and thickening of the arterial wall proximal to the ligature.5 In the arteries, mural thrombosis might occur, but thrombi could be washed away by blood flow, while the slower blood flow through the venous anastomosis produces no cleansing effect. The lower extremity is described as a site of major complications, because of anatomic position, function, and pathomorphologic processes.6 In this initial study, an elaborated technique for free-flap transfer, that prevents thrombosis of the microanastomoses, is described.
MATERIALS AND METHODS The experimental portion of the study was done on 16 mongrel dogs, with an average weight of 21 kg, under sterile conditions and using phenobarbital anesthesia. The reimplantation of a free fasciocutaneous saphenous flap was chosen as the experimental model.7 At the right pelvic extremity, the flap was raised (Fig. 1), the saphenous artery and vein were dissected out, and then anastomosed in an orthotopic position with coaptation of a saphenous nerve. At the contralateral extremity, the same procedure was done, but peripheral arteriovenous anastomoses were performed instead of ligation at the arterial and venous peripheral sites (Fig. 2). 277
Department of Plastic and Reconstructive Microsurgery and Department of Operative Surgery and Topographic Anatomy, Yaroslavl Medical Institute, Yaroslavl, Russia Dr. Sidorov is currently a Fellow in the Department of Plastic and Reconstructive Surgery at Eastern Virginia Medical School, Norfolk, VA Reprint requests-. Dr. Sidorov, Eastern Virginia Medical School, Microsurgical Research Center, 700 Olney Rd., Norfolk, VA 23507 Accepted for publication February 25, 1992 Copyright © 1992 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved.
JULY 1992
Figure 1. Raising of a neurovascular fasciocutaneous saphenous free flap in a dog model.
The animals were observed for two weeks, during which time electrophysiologic investigations and scanning electron microscopy were performed. Clinically, an elderly patient underwent excision of an irradiated malignant lesion of the left foot. A radial forearm flap with peripheral arteriovenous anastomosis was successfully transferred.
RESULTS
278
In the experimental study, on the second day after surgery, thrombosis in four of the venous anastomoses and one of the arterial ones was observed in the control group. Each of the flaps became necrotic. There was no evidence of thrombosis of anastomosed vessels at the site of the experimental extremities. Significant hyperemia of the transplanted tissue was observed in the experimental group, as contrasted to the control animals. Although edema was less in the experimental group, the mean temperature of the skin was 2.6°C higher. The pulse of the reconstructed vessels of the pedicle, as well as that of the arteriovenous fistula, was detected by the Doppler probe. Microscopic investigation of the venous anastomosis in the experimental free flaps revealed a difference in pathomorphologic changes as early as 4 hr after surgery. The histologic picture resembled an arterial anastomosis (Fig. 3). However, in two weeks, little discernible difference between control and experimental venous anastomoses could be detected by scanning electron microscopy.
CASE REPORT A 62-year-old female suffered from a melanoma (T3N0M0) of the right foot for five years. This lesion became moist and painful over an eight-month period. The patient experienced pain in her right shin when walking and nocturnal edema in her leg. On examination, the 2 x 1.5 x 1.8 cm pale pink lesion had a pocket of necrosis and was surrounded by cellulitis approximately 8 cm in diameter (Fig. 4). One month before surgery, she underwent radiotherapy to her right foot (6,150 rad centrally and 3,259 rad peripherally). The lesion was excised; the resulting defect was 12 x 7 cm. Because the tissues had been subjected to radiation and tendons were exposed in the wound, it was decided to undertake a free flap transfer to cover the defect. A fasciocutaneous flap was taken from her forearm along with the radial artery, the cephalic vein, and the antebrachial laterocutaneous nerve. The posterior tibial neurovascular bundle was exposed. The branch of the posterior tibial artery, as well as the greater saphenous vein along with the saphenous nerve, were isolated. The thickness of the arterial wall with signs of sclerotic damage was identified during surgery. There was no blood flow in the deep veins at the site of arterial anastomoses. There was marked back flow from the proximal end of the greater saphenous vein, suggesting venous hypertension. The proximal end of the radial artery was anastomosed to the posterior tibial artery and the cephalic vein to the saphenous vein. An arteriovenous fistula was then created at the
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
JOURNAL OF RECONSTRUCTIVE MICROSURGERY/VOLUME 8, NUMBER 4
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
PERIPHERAL ARTERIOVENOUS ANASTOMOSIS/SIDOROV, RECHTER, MINACHENKO
Figure 2. A, Diagram of fasciocutaneous flap with peripheral arteriovenous anastomosis. B, Peripheral arteriovenous anastomosis in the experimental free flap.
distal site of the flap, by anastomosing the distal stumps of the radial artery and cephalic vein end-toend. The nerve of the autotransplant and the saphenous nerve were coapted by epineural sutures. Splitthickness skin grafting at the donor site was done. In the early postoperative period, the transplant became hyperemic, and a distinct pulse was noted in the saphenous vein on the leg. The temperature of the shin exceeded the preoperative temperature by 2.3°C. The autotransplant survived without complications (Fig. 5), and edema was insignificant. Pain at the shin the woman had experienced preoperatively in walking was no longer present nor was the nocturnal edema. Examination six months following surgery revealed sensibility in the flap. No metastasis was observed one-and-a-half years after the transplantation.
DISCUSSION There are two methods for overcoming compromise of the inflow and outflow systems in a free flap: (1) improvement of the operative technique; or (2) initiation of medication. The first method was selected. An arteriovenous anastomosis was carried out in a distal part of fasciocutaneous flaps in experimental animals and in a hospital patient. It is believed that a peripheral arteriovenous anastomosis in a flow-through free flap increases blood flow in the vein, as well as its resistance to external pressure. Additionally, it provides direct and rapid disposal of excess arterial blood and prevents the formation of mural thrombosis in anastomosed
279
m wmmmrsm
JULY 1992
•
B
Figure 3. Scanning electron microscopy of anastomosed vein of the saphenous free flap 4 hr after surgery. A, Experimental free flap; single blood cells can be seen (SEM X40). B, Control free flap; "head" of a mural thrombus. Note three-dimensional framework of fibrin strands with platelets (SEM X3500). C, Control free flap; "tail" of a thrombus. Note delicate three-dimensional framework of fibrin strands with erythrocytes and platelets (SEM x 1700).
vessels distally (no stumps of artery and vein in the The elevation of the temperature of the transplant is flap); it also improves drainage capabilities of the a consequence of the enrichment of arterial blood flow venous system in the autotransplant, as well as in the through the venous system. recipient region. The point of view expressed above was taken as The creation of an arteriovenous fistula within the the basis for a clinical procedure. The arteriovenous flap solved the problem of purging the venous anasto- anastomosis enabled the free fasciocutaneous flap to mosis of mural thromboses. Statistically significant survive under conditions of radiation injury to the results in the experimental group could be ascribed recipient tissue and vascular insufficiency of the exto a change of hemodynamic conditions in the anasto- tremity. Disappearance of pain in the shin is explained 280 mosed vein, which began to resemble arterial ones. by the improvement of arterial blood supply and
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
JOURNAL OF RECONSTRUCTIVE MICROSURGERY/VOLUME 8, NUMBER 4
PERIPHERAL ARTERIOVENOUS ANASTOMOSIS/SIDOROV, RECHTER, MINACHENKO
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
Figure 4. Irradiated melanoma of the right foot.
venous drainage. It appears that the quick occlusion of an arteriovenous fistula may be initiated at any time without serious consequences. It is important to note that the idea for the creation of a peripheral arteriovenous anastomosis in a free flap was a result of the success obtained through the use of venous flap transfer,8-10 free flap transfer without venous return,11 and arterialized venous flaps.12-15
The proposed operative technique could be an alternative to the traditional method of a free flap transfer. This suggests a technology of preventing early thrombosis of the anastomosed vessels in general, and particularly under conditions of insufficiency of the recipient vascular system. At the same time, it does not exclude additional analysis and further clinical evaluation of the initial procedure presented above.
"REFERENCES 1.
Figure 5. After transfer of the radial fasciocutaneous free flap with peripheral arteriovenous anastomosis.
Acland RD, Trachtenberg I: The histopathology of small arteries following experimental microvascular anastomosis. Plast Reconstr Surg 60:868, 1979 2. Baxter TY, O'Brien B, Henderson PN, Bennet RG HistopatholOgy of small vessels following microvascular reconstruction. Br I Surg 59617, 1972 3 Godina M: Preferential use of end-to-side arterial anastomoses in free flap transfers. Plast Reconstr Surg 64:673, 1979 4 Lidman D, Daniel RK: Evaluation of clinical microvascular anastomoses: Reasons for failure. Ann Plast Surg 6:215, 1981 5. Fukui A, Tamai S: Factors influencing the failure of microsurgical composite tissue transplantation.) Reconstr Microsurg 4:285, 1988 6. Serafin D, Voci VE: Reconstruction of the lower extremity: Microsurgical composite tissue transplantation. Clin Plast Surg 10:55, 1983
281
JOURNAL OF RECONSTRUCTIVE MICROSURGERY/VOLUME 8, NUMBER 4 Banis JC, Schwartz KS, Acland RD: Electromagnetic flowmetry: An experimental model for continuous blood flow measurement using a new island flap. Plast Reconstr Surg 66: 534, 1980 8. Beak SM, Weinberg HY, Park CG: Experimental studies in survival of venous flaps without arterial flow. Plast Reconstr Surg 75:88, 1985 9. Fukui A, Inada Y, Tamai S, et al: Skin graft including subcutaneous vein: Experimental study and clinical applications. J Reconstr Microsurg 4:223, 1988 10. Thatte RL, Thatte MR: A study of the saphenous venous island flap in the dog without arterial inflow using a non-biological conduit across a part of the length of the vein. Br I Plast Surg 40:11, 1987
11.
Erer CM, Cerkes N, Ersezen C: Survival of a free radial forearm flap without venous return. Br J Plast Surg 44:60, 1991 12. Inoue G, Maeda N, Suzuki K: Closure of big toe defects after wrap-around flap transfer using the arterialized venous flap. | Reconstr Microsurg 7:1, 1991 13. Koshima ), Soeda S, Nakayama ), et al: An arterialized venous flap using the long saphenous vein. Br I Plast Surg 44:23, 1991 14. Amarante I, Costa H, Reis ), Soares R: Venous skin flaps: An experimental study and report of two clinical distal island flaps. Br I Plast Surg 41:132, 1988 15. Sasa M.Xian WQ, Breidenbach W, etal.-. Survival and blood flow evaluation of canine venous flaps. Plast Reconstr Surg 82: 319, 1988
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
7.
JULY 1992
PERIPHERAL ARTERIOVENOUS ANASTOMOSIS: A N ALTERNATIVE TECHNIQUE Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
A FREE FLAP TRANSFER ABSTRACT Prevention of thrombosis in the inflow and outflow vessels of a free flap is a problem of current interest. The method of creating a peripheral arteriovenous anastomosis within a free flap was validated in an experimental study and substantiated in a clinical case. No thrombotic complications were observed in 16 transfers of saphenous fasciocutaneous flaps in a dog model, as well as in an elderly patient with free radial forearm flap transfer to an irradiated foot. Scanning electron microscopy of the venous anastomosis proximal to the arteriovenous fistula revealed the difference of pathologic changes as early as 4 hr following surgery. It is the conclusion of the authors, that performing a distal arteriovenous fistula in a free flap, is an effective procedure for prevention of early occlusion in a proximally anastomosed artery and vein.
Failure of free-flap transfers is usually associated with thrombosis of the microanastomoses. The thrombosis occurs at the venous, as well as at the arterial, site.'- 4 Ligation of the anastomosed artery at the periphery of the flap leads to a dramatic change of blood flow and thickening of the arterial wall proximal to the ligature.5 In the arteries, mural thrombosis might occur, but thrombi could be washed away by blood flow, while the slower blood flow through the venous anastomosis produces no cleansing effect. The lower extremity is described as a site of major complications, because of anatomic position, function, and pathomorphologic processes.6 In this initial study, an elaborated technique for free-flap transfer, that prevents thrombosis of the microanastomoses, is described.
MATERIALS AND METHODS The experimental portion of the study was done on 16 mongrel dogs, with an average weight of 21 kg, under sterile conditions and using phenobarbital anesthesia. The reimplantation of a free fasciocutaneous saphenous flap was chosen as the experimental model.7 At the right pelvic extremity, the flap was raised (Fig. 1), the saphenous artery and vein were dissected out, and then anastomosed in an orthotopic position with coaptation of a saphenous nerve. At the contralateral extremity, the same procedure was done, but peripheral arteriovenous anastomoses were performed instead of ligation at the arterial and venous peripheral sites (Fig. 2). 277
Department of Plastic and Reconstructive Microsurgery and Department of Operative Surgery and Topographic Anatomy, Yaroslavl Medical Institute, Yaroslavl, Russia Dr. Sidorov is currently a Fellow in the Department of Plastic and Reconstructive Surgery at Eastern Virginia Medical School, Norfolk, VA Reprint requests-. Dr. Sidorov, Eastern Virginia Medical School, Microsurgical Research Center, 700 Olney Rd., Norfolk, VA 23507 Accepted for publication February 25, 1992 Copyright © 1992 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved.
JULY 1992
Figure 1. Raising of a neurovascular fasciocutaneous saphenous free flap in a dog model.
The animals were observed for two weeks, during which time electrophysiologic investigations and scanning electron microscopy were performed. Clinically, an elderly patient underwent excision of an irradiated malignant lesion of the left foot. A radial forearm flap with peripheral arteriovenous anastomosis was successfully transferred.
RESULTS
278
In the experimental study, on the second day after surgery, thrombosis in four of the venous anastomoses and one of the arterial ones was observed in the control group. Each of the flaps became necrotic. There was no evidence of thrombosis of anastomosed vessels at the site of the experimental extremities. Significant hyperemia of the transplanted tissue was observed in the experimental group, as contrasted to the control animals. Although edema was less in the experimental group, the mean temperature of the skin was 2.6°C higher. The pulse of the reconstructed vessels of the pedicle, as well as that of the arteriovenous fistula, was detected by the Doppler probe. Microscopic investigation of the venous anastomosis in the experimental free flaps revealed a difference in pathomorphologic changes as early as 4 hr after surgery. The histologic picture resembled an arterial anastomosis (Fig. 3). However, in two weeks, little discernible difference between control and experimental venous anastomoses could be detected by scanning electron microscopy.
CASE REPORT A 62-year-old female suffered from a melanoma (T3N0M0) of the right foot for five years. This lesion became moist and painful over an eight-month period. The patient experienced pain in her right shin when walking and nocturnal edema in her leg. On examination, the 2 x 1.5 x 1.8 cm pale pink lesion had a pocket of necrosis and was surrounded by cellulitis approximately 8 cm in diameter (Fig. 4). One month before surgery, she underwent radiotherapy to her right foot (6,150 rad centrally and 3,259 rad peripherally). The lesion was excised; the resulting defect was 12 x 7 cm. Because the tissues had been subjected to radiation and tendons were exposed in the wound, it was decided to undertake a free flap transfer to cover the defect. A fasciocutaneous flap was taken from her forearm along with the radial artery, the cephalic vein, and the antebrachial laterocutaneous nerve. The posterior tibial neurovascular bundle was exposed. The branch of the posterior tibial artery, as well as the greater saphenous vein along with the saphenous nerve, were isolated. The thickness of the arterial wall with signs of sclerotic damage was identified during surgery. There was no blood flow in the deep veins at the site of arterial anastomoses. There was marked back flow from the proximal end of the greater saphenous vein, suggesting venous hypertension. The proximal end of the radial artery was anastomosed to the posterior tibial artery and the cephalic vein to the saphenous vein. An arteriovenous fistula was then created at the
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
JOURNAL OF RECONSTRUCTIVE MICROSURGERY/VOLUME 8, NUMBER 4
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
PERIPHERAL ARTERIOVENOUS ANASTOMOSIS/SIDOROV, RECHTER, MINACHENKO
Figure 2. A, Diagram of fasciocutaneous flap with peripheral arteriovenous anastomosis. B, Peripheral arteriovenous anastomosis in the experimental free flap.
distal site of the flap, by anastomosing the distal stumps of the radial artery and cephalic vein end-toend. The nerve of the autotransplant and the saphenous nerve were coapted by epineural sutures. Splitthickness skin grafting at the donor site was done. In the early postoperative period, the transplant became hyperemic, and a distinct pulse was noted in the saphenous vein on the leg. The temperature of the shin exceeded the preoperative temperature by 2.3°C. The autotransplant survived without complications (Fig. 5), and edema was insignificant. Pain at the shin the woman had experienced preoperatively in walking was no longer present nor was the nocturnal edema. Examination six months following surgery revealed sensibility in the flap. No metastasis was observed one-and-a-half years after the transplantation.
DISCUSSION There are two methods for overcoming compromise of the inflow and outflow systems in a free flap: (1) improvement of the operative technique; or (2) initiation of medication. The first method was selected. An arteriovenous anastomosis was carried out in a distal part of fasciocutaneous flaps in experimental animals and in a hospital patient. It is believed that a peripheral arteriovenous anastomosis in a flow-through free flap increases blood flow in the vein, as well as its resistance to external pressure. Additionally, it provides direct and rapid disposal of excess arterial blood and prevents the formation of mural thrombosis in anastomosed
279
m wmmmrsm
JULY 1992
•
B
Figure 3. Scanning electron microscopy of anastomosed vein of the saphenous free flap 4 hr after surgery. A, Experimental free flap; single blood cells can be seen (SEM X40). B, Control free flap; "head" of a mural thrombus. Note three-dimensional framework of fibrin strands with platelets (SEM X3500). C, Control free flap; "tail" of a thrombus. Note delicate three-dimensional framework of fibrin strands with erythrocytes and platelets (SEM x 1700).
vessels distally (no stumps of artery and vein in the The elevation of the temperature of the transplant is flap); it also improves drainage capabilities of the a consequence of the enrichment of arterial blood flow venous system in the autotransplant, as well as in the through the venous system. recipient region. The point of view expressed above was taken as The creation of an arteriovenous fistula within the the basis for a clinical procedure. The arteriovenous flap solved the problem of purging the venous anasto- anastomosis enabled the free fasciocutaneous flap to mosis of mural thromboses. Statistically significant survive under conditions of radiation injury to the results in the experimental group could be ascribed recipient tissue and vascular insufficiency of the exto a change of hemodynamic conditions in the anasto- tremity. Disappearance of pain in the shin is explained 280 mosed vein, which began to resemble arterial ones. by the improvement of arterial blood supply and
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
JOURNAL OF RECONSTRUCTIVE MICROSURGERY/VOLUME 8, NUMBER 4
PERIPHERAL ARTERIOVENOUS ANASTOMOSIS/SIDOROV, RECHTER, MINACHENKO
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
Figure 4. Irradiated melanoma of the right foot.
venous drainage. It appears that the quick occlusion of an arteriovenous fistula may be initiated at any time without serious consequences. It is important to note that the idea for the creation of a peripheral arteriovenous anastomosis in a free flap was a result of the success obtained through the use of venous flap transfer,8-10 free flap transfer without venous return,11 and arterialized venous flaps.12-15
The proposed operative technique could be an alternative to the traditional method of a free flap transfer. This suggests a technology of preventing early thrombosis of the anastomosed vessels in general, and particularly under conditions of insufficiency of the recipient vascular system. At the same time, it does not exclude additional analysis and further clinical evaluation of the initial procedure presented above.
"REFERENCES 1.
Figure 5. After transfer of the radial fasciocutaneous free flap with peripheral arteriovenous anastomosis.
Acland RD, Trachtenberg I: The histopathology of small arteries following experimental microvascular anastomosis. Plast Reconstr Surg 60:868, 1979 2. Baxter TY, O'Brien B, Henderson PN, Bennet RG HistopatholOgy of small vessels following microvascular reconstruction. Br I Surg 59617, 1972 3 Godina M: Preferential use of end-to-side arterial anastomoses in free flap transfers. Plast Reconstr Surg 64:673, 1979 4 Lidman D, Daniel RK: Evaluation of clinical microvascular anastomoses: Reasons for failure. Ann Plast Surg 6:215, 1981 5. Fukui A, Tamai S: Factors influencing the failure of microsurgical composite tissue transplantation.) Reconstr Microsurg 4:285, 1988 6. Serafin D, Voci VE: Reconstruction of the lower extremity: Microsurgical composite tissue transplantation. Clin Plast Surg 10:55, 1983
281
JOURNAL OF RECONSTRUCTIVE MICROSURGERY/VOLUME 8, NUMBER 4 Banis JC, Schwartz KS, Acland RD: Electromagnetic flowmetry: An experimental model for continuous blood flow measurement using a new island flap. Plast Reconstr Surg 66: 534, 1980 8. Beak SM, Weinberg HY, Park CG: Experimental studies in survival of venous flaps without arterial flow. Plast Reconstr Surg 75:88, 1985 9. Fukui A, Inada Y, Tamai S, et al: Skin graft including subcutaneous vein: Experimental study and clinical applications. J Reconstr Microsurg 4:223, 1988 10. Thatte RL, Thatte MR: A study of the saphenous venous island flap in the dog without arterial inflow using a non-biological conduit across a part of the length of the vein. Br I Plast Surg 40:11, 1987
11.
Erer CM, Cerkes N, Ersezen C: Survival of a free radial forearm flap without venous return. Br J Plast Surg 44:60, 1991 12. Inoue G, Maeda N, Suzuki K: Closure of big toe defects after wrap-around flap transfer using the arterialized venous flap. | Reconstr Microsurg 7:1, 1991 13. Koshima ), Soeda S, Nakayama ), et al: An arterialized venous flap using the long saphenous vein. Br I Plast Surg 44:23, 1991 14. Amarante I, Costa H, Reis ), Soares R: Venous skin flaps: An experimental study and report of two clinical distal island flaps. Br I Plast Surg 41:132, 1988 15. Sasa M.Xian WQ, Breidenbach W, etal.-. Survival and blood flow evaluation of canine venous flaps. Plast Reconstr Surg 82: 319, 1988
Downloaded by: University of Pennsylvania Libraries. Copyrighted material.
7.
JULY 1992
