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The Doppler and its use in axial flaps
The Doppler and Its Use in Axial Flaps Theodore I?. Corwin, MD, Gainesville, Hal G. Bingham, MD, Gainesville,
Florida
Florida
The Doppler or ultrasonic flowmeter has proved to have wide applicability in vascular problems [1,2]. This electronic device allows determination of pulsatile flow of blood through intact skin preoperatively, within a surgical wound during operation, or postoperatively after wound closure. Measurements can be repeated many times without side effects and the small portable instrument can be used at the bedside, in the clinic, or in the operating room. Axial flaps and, more recently, free island flaps with microvascular anastomoses have been widely used [3-61. Vascular supply is the critical denominator in all flaps, particularly axial and free island flaps. The location of the vascular supply must be determined precisely with the initial outlining of the flap, and the patency of the vessel or vessels must be maintained during and after flap transfer. The Doppler seemed to provide a noninvasive monitor for vascular flow even in vessels 1 mm in diameter and therefore appeared to be the logical instrument for our clinical work on axial flaps as well as our experimental research on microvascular transfers.
correctly outlined. Smith et al [S] suggested after extensive anatomic study that the superficial circumflex iliac artery could be located 1 inch below the midpoint of the inguinal ligament and 1 inch below the anterior superior iliac spine. They suggested that groin flaps should be centered around this axis. (Figure 1A.) The axis of the groin flaps in our patient was found with the use of the Doppler to be almost directly above the inguinal ligament. This location of the superficial circumflex iliac artery was at least 1 inch cephalad from where it should have been. We believed that the radiation dermatitis and cicatrix had caused a cephalad migration of the axial vessels. (Figures 1B and 1C.) The Doppler can also be applied in monitoring of free axial island grafts. Daniel and Williams [9] described a method of intraoperative assessment of flap viability that required an incision in the flap. Brisk red bleeding indi-
Clinical Application We have used the Doppler to locate the vascular supply of several axial flaps. A temporal island flap with its axial vessels was easily defined by the Doppler as was a supratrochlear Jonathan Livingston Seagull flap [7]. The variation in the vascular supply of bilateral groin flaps in a patient who had previously been irradiated was significant to the point that had the Doppler not been used to define the axial vessels, the flaps would have been inFrom the University of Florida Medical Center, G%nesville. Florida. Reprint requests should be addressed to Hal G. Bingham, MD, Division of Plastic Surgery. University of Flori& Medical Center, Gainesville, Florida 326 10.
660
Figure 1A. The super&w circumflex iliac artery is described as being I inch below the inguinal ligament.
The American Journal of Surgery
Doppler and Axial Flaps
Figure 1B. The actual location of the vessel can be detected by the Doppler.
Figure 2. Tracing of dicrotic arterial pulse before, during, and after occlusion with Doppler. Use as a Research
Tool
The skin of the domestic pig has been described as a most ideal model for experimentation with the island flap technic, for its vessel distribution is similar to that of hu-
Figure 7C. Detection of the vessel avoids flap failure.
cated both vessels to be patent, no bleeding indicated an arterial block, and dark blue bleeding indicated a venous block. Daniel and Williams [9] also described various adjuncts for determining the fate of the flap postoperatively, such as arteriography, intravital dyes, and vascular casts. We did not find it necessary to use any of the adjunctive methods to determine flap viability either intraoperatively or postoperatively when the Doppler was employed. The arterial pulse or dicrotic wave can be readily heard or seen on electrocardiogram tracing and the venous continuous hum can be heard equally well. (Figure 2.) The use of the Doppler does not require any invasive technic on the flap, which in itself can cause damage to the vascular supply. Also, the Doppler evaluation can be accomplished preoperatively to find the axial vessels and then intraoperatively during the outlining and elevation of the flap. After anastomosis, the Doppler probe can be placed proximal and distal to the union to determine patency. This noninvasive evaluation may be repeated many times.
Volume131,JunelB78
mans in its segmental, musculocutaneous, and cutaneous systems [IO]. The panniculus carnosus in other laboratory animals, such as the dog with its modified cutaneous vascular system, differs from the skin of pig and man. However, it is interesting that one of the earliest studies on microvascular anastomosis of island flaps was carried out in the dog [II]. For various reasons the pig proved to be a poor experimental model, but we did find a strong correlation between our Doppler findings and flap failure. In none of the island flap transfers that required microvascular anastomosis did we hear adequate flow with the Doppler, and none of the flaps survived. Part of the problem may have been due to inexperience of the investigators who worked with the microscope. We next selected the dog as an experimental model. Five dogs have undergone island flap transfer with use of the Doppler to locate the important vessels. The circumflex iliac groin flap was transferred, as well as inferior epigastric island flap, to the external facial artery and vein. After the anastomosis was completed, the vascular flow was monitored both proximal and distal to the union. (Figures 3A and 3B.) The dicrotic arterial sound could always be heard with more intensity proximal to the anastomosis, but it was possible to hear a sound of diminished intensity distal to the anastomosis and through the intact skin of the flap. (Figure 3C.) Venous continuous hum
661
Corwin and Bingham
sounds were nearly the same intensity as the arterial sounds in the various areas. Xylocaine@, 1 per cent solution, was used to continuously bathe the open wound, and heparin, 100 units/kg of body weight, was administered before division of the donor vessels. The Doppler ultrasonic device gave evidence of the island flap viability upon completion of the procedure, although the flap sometimes appeared slightly pale with slow capillary refill after it was sutured in place.
Ftgure 3A. Pulsation, recorded with the Doppler, proximal to the completed arterial anastomosis.
Ftgure 38. Pulsation, recorded with the Doppler, distal to the arterial anastomosts.
Postoperatively, the animals received penicillin, 600,000 units twice a day, and heparin, 100 units/kg of body weight twice a day. The Doppler was subsequently used on the
dogs to recheck for arterial and venous sounds through the intact flap. Comments
We have used the Doppler ultrasonic flowmeter as an aid in solving several different problems that require monitoring axial and free island flaps. Vascular supply is the critical denominator in these flaps and locating the vessels is relatively easy when the Doppler probe is used. Sterile lubricating gel used as an ultrasound conductor enables the examiners to hear flow through intact skin. Variation in location of vessels occurs not only in individuals who have been managed with differing modalities such as radiotherapy but also in normal patients. We attempted to extend the use of the Doppler into microvascular surgery in both the laboratory and clinic. It has been valuable in locating small vessels through intact skin and in open surgical wounds. Once anastomosis of these microvessels has been accomplished, the Doppler has aided in demonstrating pulsatile flow both proximal and distal to the point of union, A continuous venous hum can usually be detected across an anastomosis between two small veins. Postoperatively microvessels can be heard with the Doppler through the intact skin after the flap has been sutured in place. This particular examination can be repeated on many occasions to assure continued patency of the microvascular anastomoses. If it becomes obvious that the dicrotic pulsatile flow has diminished, reintervention at the anastomotic site may be considered along with other alternatives such as heparin. Our intent in the future is to objectively determine the critical level of diminished flow beyond which thrombosis will occur.
Figure 3C. Pulsation, recorded with the Doppler, through the flap after it has been sutured in place.
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The American Journal 01 Surgery
Doppler
Summary The Doppler ultrasonic flowmeter has been used as an aid in locating blood vessels that supply axial flaps in several different clinical situations. It has also been of value in microvascular surgery in which axial vessels of island flaps can be located and continuous patency monitored after their transfer and anastomosis. Acknowledgment: We thank Miss Sherry Veltkamp for the illustrations and Mr Bill Lineaweaver for his technical assistance in the laboratory. References 1. Bingham HG, Lichti E: Use of ultrasound transducer (Doppler) to localize arteriovenous fistulae. flast Reconstr Surg 46: 151, 1970. 2. Gurucharri V, Henzel JH, Mitchell FL: Use of the Doppler flowmeter to monitor the peripheral blood flow during the edema stage of snakebite. Plast Reconstr Surg 53: 551,
Volume 131, June 197%
and Axial Flaps
1974. 3. Krizek TJ, Tani T, Desprez JD, Kiehn CL: Experimental transplantation of composite grafts by microsurgical anastomoses. Plast Reconstr Surg 36: 538, 1965. 4. Strauch B, Murray DE: Transfer of composite graft with immediate suture anastomosis of its vascular pedicle measuring less than one millimeter in external diameter using microsurgical techniques. Plast Reconstr Surg 40: 325. 1967. 5. McLean DH, Buncke HJ, Jr: Autotransplant of omentum to a large scalp defect with microsurgical revascularization. flast Reconstr Surg 49: 268, 1972. 6. O’Brien BM. Morrison WA, lshida H, MacLeod, AM, Gilbert A: Free flap transfers with microvascular anastomoses. Br J Plast Surg 27: 220, 1974. 7. Millard DR: Reconstructive rhinoplasty for the lower half of the nose. Plast Reconstr Surg 53: 133, 1974. 8. Smith PJ, Foley B, McGregor IA, Jackson IT: The anatomical basis of the groin flap. Plast Reconstr Surg 49: 41, 1972. 9. Daniel RK, Williams HB: The free transfer of skin flaps by microvascular anastomoses. Plast Reconstr Surg 52: 16. 1973. 10. Montanga W, Yun JS: The skin of the domestic pig. J /west Dermatol43: 11, 1964. 11. Goldwyn RM, Lamb DL, White WL: An experimental study of large island flaps in dogs. Plast Reconstr Surg 31: 528, 1963.
663
Florida
Florida
The Doppler or ultrasonic flowmeter has proved to have wide applicability in vascular problems [1,2]. This electronic device allows determination of pulsatile flow of blood through intact skin preoperatively, within a surgical wound during operation, or postoperatively after wound closure. Measurements can be repeated many times without side effects and the small portable instrument can be used at the bedside, in the clinic, or in the operating room. Axial flaps and, more recently, free island flaps with microvascular anastomoses have been widely used [3-61. Vascular supply is the critical denominator in all flaps, particularly axial and free island flaps. The location of the vascular supply must be determined precisely with the initial outlining of the flap, and the patency of the vessel or vessels must be maintained during and after flap transfer. The Doppler seemed to provide a noninvasive monitor for vascular flow even in vessels 1 mm in diameter and therefore appeared to be the logical instrument for our clinical work on axial flaps as well as our experimental research on microvascular transfers.
correctly outlined. Smith et al [S] suggested after extensive anatomic study that the superficial circumflex iliac artery could be located 1 inch below the midpoint of the inguinal ligament and 1 inch below the anterior superior iliac spine. They suggested that groin flaps should be centered around this axis. (Figure 1A.) The axis of the groin flaps in our patient was found with the use of the Doppler to be almost directly above the inguinal ligament. This location of the superficial circumflex iliac artery was at least 1 inch cephalad from where it should have been. We believed that the radiation dermatitis and cicatrix had caused a cephalad migration of the axial vessels. (Figures 1B and 1C.) The Doppler can also be applied in monitoring of free axial island grafts. Daniel and Williams [9] described a method of intraoperative assessment of flap viability that required an incision in the flap. Brisk red bleeding indi-
Clinical Application We have used the Doppler to locate the vascular supply of several axial flaps. A temporal island flap with its axial vessels was easily defined by the Doppler as was a supratrochlear Jonathan Livingston Seagull flap [7]. The variation in the vascular supply of bilateral groin flaps in a patient who had previously been irradiated was significant to the point that had the Doppler not been used to define the axial vessels, the flaps would have been inFrom the University of Florida Medical Center, G%nesville. Florida. Reprint requests should be addressed to Hal G. Bingham, MD, Division of Plastic Surgery. University of Flori& Medical Center, Gainesville, Florida 326 10.
660
Figure 1A. The super&w circumflex iliac artery is described as being I inch below the inguinal ligament.
The American Journal of Surgery
Doppler and Axial Flaps
Figure 1B. The actual location of the vessel can be detected by the Doppler.
Figure 2. Tracing of dicrotic arterial pulse before, during, and after occlusion with Doppler. Use as a Research
Tool
The skin of the domestic pig has been described as a most ideal model for experimentation with the island flap technic, for its vessel distribution is similar to that of hu-
Figure 7C. Detection of the vessel avoids flap failure.
cated both vessels to be patent, no bleeding indicated an arterial block, and dark blue bleeding indicated a venous block. Daniel and Williams [9] also described various adjuncts for determining the fate of the flap postoperatively, such as arteriography, intravital dyes, and vascular casts. We did not find it necessary to use any of the adjunctive methods to determine flap viability either intraoperatively or postoperatively when the Doppler was employed. The arterial pulse or dicrotic wave can be readily heard or seen on electrocardiogram tracing and the venous continuous hum can be heard equally well. (Figure 2.) The use of the Doppler does not require any invasive technic on the flap, which in itself can cause damage to the vascular supply. Also, the Doppler evaluation can be accomplished preoperatively to find the axial vessels and then intraoperatively during the outlining and elevation of the flap. After anastomosis, the Doppler probe can be placed proximal and distal to the union to determine patency. This noninvasive evaluation may be repeated many times.
Volume131,JunelB78
mans in its segmental, musculocutaneous, and cutaneous systems [IO]. The panniculus carnosus in other laboratory animals, such as the dog with its modified cutaneous vascular system, differs from the skin of pig and man. However, it is interesting that one of the earliest studies on microvascular anastomosis of island flaps was carried out in the dog [II]. For various reasons the pig proved to be a poor experimental model, but we did find a strong correlation between our Doppler findings and flap failure. In none of the island flap transfers that required microvascular anastomosis did we hear adequate flow with the Doppler, and none of the flaps survived. Part of the problem may have been due to inexperience of the investigators who worked with the microscope. We next selected the dog as an experimental model. Five dogs have undergone island flap transfer with use of the Doppler to locate the important vessels. The circumflex iliac groin flap was transferred, as well as inferior epigastric island flap, to the external facial artery and vein. After the anastomosis was completed, the vascular flow was monitored both proximal and distal to the union. (Figures 3A and 3B.) The dicrotic arterial sound could always be heard with more intensity proximal to the anastomosis, but it was possible to hear a sound of diminished intensity distal to the anastomosis and through the intact skin of the flap. (Figure 3C.) Venous continuous hum
661
Corwin and Bingham
sounds were nearly the same intensity as the arterial sounds in the various areas. Xylocaine@, 1 per cent solution, was used to continuously bathe the open wound, and heparin, 100 units/kg of body weight, was administered before division of the donor vessels. The Doppler ultrasonic device gave evidence of the island flap viability upon completion of the procedure, although the flap sometimes appeared slightly pale with slow capillary refill after it was sutured in place.
Ftgure 3A. Pulsation, recorded with the Doppler, proximal to the completed arterial anastomosis.
Ftgure 38. Pulsation, recorded with the Doppler, distal to the arterial anastomosts.
Postoperatively, the animals received penicillin, 600,000 units twice a day, and heparin, 100 units/kg of body weight twice a day. The Doppler was subsequently used on the
dogs to recheck for arterial and venous sounds through the intact flap. Comments
We have used the Doppler ultrasonic flowmeter as an aid in solving several different problems that require monitoring axial and free island flaps. Vascular supply is the critical denominator in these flaps and locating the vessels is relatively easy when the Doppler probe is used. Sterile lubricating gel used as an ultrasound conductor enables the examiners to hear flow through intact skin. Variation in location of vessels occurs not only in individuals who have been managed with differing modalities such as radiotherapy but also in normal patients. We attempted to extend the use of the Doppler into microvascular surgery in both the laboratory and clinic. It has been valuable in locating small vessels through intact skin and in open surgical wounds. Once anastomosis of these microvessels has been accomplished, the Doppler has aided in demonstrating pulsatile flow both proximal and distal to the point of union, A continuous venous hum can usually be detected across an anastomosis between two small veins. Postoperatively microvessels can be heard with the Doppler through the intact skin after the flap has been sutured in place. This particular examination can be repeated on many occasions to assure continued patency of the microvascular anastomoses. If it becomes obvious that the dicrotic pulsatile flow has diminished, reintervention at the anastomotic site may be considered along with other alternatives such as heparin. Our intent in the future is to objectively determine the critical level of diminished flow beyond which thrombosis will occur.
Figure 3C. Pulsation, recorded with the Doppler, through the flap after it has been sutured in place.
662
The American Journal 01 Surgery
Doppler
Summary The Doppler ultrasonic flowmeter has been used as an aid in locating blood vessels that supply axial flaps in several different clinical situations. It has also been of value in microvascular surgery in which axial vessels of island flaps can be located and continuous patency monitored after their transfer and anastomosis. Acknowledgment: We thank Miss Sherry Veltkamp for the illustrations and Mr Bill Lineaweaver for his technical assistance in the laboratory. References 1. Bingham HG, Lichti E: Use of ultrasound transducer (Doppler) to localize arteriovenous fistulae. flast Reconstr Surg 46: 151, 1970. 2. Gurucharri V, Henzel JH, Mitchell FL: Use of the Doppler flowmeter to monitor the peripheral blood flow during the edema stage of snakebite. Plast Reconstr Surg 53: 551,
Volume 131, June 197%
and Axial Flaps
1974. 3. Krizek TJ, Tani T, Desprez JD, Kiehn CL: Experimental transplantation of composite grafts by microsurgical anastomoses. Plast Reconstr Surg 36: 538, 1965. 4. Strauch B, Murray DE: Transfer of composite graft with immediate suture anastomosis of its vascular pedicle measuring less than one millimeter in external diameter using microsurgical techniques. Plast Reconstr Surg 40: 325. 1967. 5. McLean DH, Buncke HJ, Jr: Autotransplant of omentum to a large scalp defect with microsurgical revascularization. flast Reconstr Surg 49: 268, 1972. 6. O’Brien BM. Morrison WA, lshida H, MacLeod, AM, Gilbert A: Free flap transfers with microvascular anastomoses. Br J Plast Surg 27: 220, 1974. 7. Millard DR: Reconstructive rhinoplasty for the lower half of the nose. Plast Reconstr Surg 53: 133, 1974. 8. Smith PJ, Foley B, McGregor IA, Jackson IT: The anatomical basis of the groin flap. Plast Reconstr Surg 49: 41, 1972. 9. Daniel RK, Williams HB: The free transfer of skin flaps by microvascular anastomoses. Plast Reconstr Surg 52: 16. 1973. 10. Montanga W, Yun JS: The skin of the domestic pig. J /west Dermatol43: 11, 1964. 11. Goldwyn RM, Lamb DL, White WL: An experimental study of large island flaps in dogs. Plast Reconstr Surg 31: 528, 1963.
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