Venous drainage of the radial forearm and anterior tibial reverse flow flaps: anatomical and radiographic perfusion studies

Lateral supramalleolar flap for coverage of ankle and foot defects in children

The lower part of the leg, the ankle and the foot, is a difficult region to cover especially with exposure of bones or tendons. There are many options for covering soft tissue defect in these areas. The supramalleolar flap is an interesting procedure. The lateral supramalleolar flap was used in 8 cases for the reconstruction of skin defects of the ankle, heel, and foot that compromised the Achilles tendon and the osteoarticular system. Of the 8 patients, 5 were males and 3 were females, with an average age of 6.4 (range 2 to 10) years. The skin defect was secondary to trauma in all cases. The mean follow-up period was 31 (range 19 to 47) months; at the last follow-up visit, the region had been successfully covered in all cases. No necrosis of the flap was reported. The donor site morbidity was minimal. The lateral supramalleolar flap is an interesting surgical technique to salvage the lower extremity in children because this flap has a large skin paddle and a wide rotation arc and is based on a secondary vascular axis.

Distally based dorsal pedal neurocutaneous flap for forefoot coverage

The authors describe their experience with the use of the distally based dorsal pedal neurocutaneous flap for distal foot coverage. Ten patients underwent reconstruction with 13 flaps between 2004 and 2008. One patient suffered from a traffic accident and 9 from electrical injury. All of the soft tissue defects resulted in metatarsophalangeal joint and phalanx bone exposure. The size of the flaps ranged from 6 × 2 cm to 11 × 6 cm. The flaps were elevated based on intermediate or medial dorsal pedal nerves. Nine flaps were harvested in first stage to repair the distal foot. Among them, 3 showed partial necrosis in the distal region because of venous insufficiency. Four flaps underwent a surgical delay procedure in the first stage and were then transferred to reconstruct phalanx wounds in the second stage, surviving completely. All patients were satisfied with their reconstruction and donor site contour. The distally based dorsal pedal neurocutaneous flap can be used to repair the distal foot soft tissue defects, providing sufficient skin territory and excellent aesthetic and functional recovery. Surgical delay effectively enhances the distally based dorsal pedal neurocutaneous flap survival, particularly for the large size flaps.

Venous drainage in retrograde island flap: an experimental study using fluorescence tracing technique

The pathway of venous drainage in retrograde island flaps was investigated by fluorescence tracing technique using the saphenous fasciocutaneous flap in New Zealand White rabbits. Forty animals were allocated into four groups according to the different times at 30 minutes (I), 24 hours (II), 72 hours (III), and 7 days (IV) after the operation. According to the different routes to give tracer, each group was further allocated into two subgroups of the artery injection and vein injection. For each animal, one hindlimb was assigned as the experimental side, the contralateral side as control without giving tracer. The erythrocytes were separated, labeled with fluorescein isothiocyanate (FITC), detected, and injected into the artery or vein. Subsequently, the flaps were harvested 5 seconds after injection and immediately frozen, sectioned, and observed under microscope. In group I and II, the fluorescence was observed mainly around the vessel adventitia of the vein and artery and tunica intima of the artery. In group III, there was weak fluorescence observed in the lumen of vein. In group IV, fluorescence was distributed principally in the lumen of the vein. In addition, fluorescence was not observed in the saphenous nerve in group I and there was mild fluorescence in the saphenous nerve in groups II, III, and IV. These findings suggest that the venous return is through "bypass route" in earlier period. In later period, the venous retrograde return is through "bypass route" and "incompetent valves route;" however, "incompetent valves route" becomes the main route.

The effect of epidural anaesthesia on the reverse-flow fasciocutaneous flap: an experimental study in rabbits

BACKGROUND

The reverse-flow fasciocutaneous flap has been popularised as a feasible alternative to reconstruction of the post-burn contractures around lower-extremity joints. The effect of epidural anaesthesia (EA) on the haemodynamics of reverse-flow fasciocutaneous flap (RFFF) has not yet been investigated. Therefore, it was our primary objective to determine how EA impacts on vascular haemodynamics and tissue perfusion.

MATERIALS AND METHODS

This study included 30 New Zealand white rabbits. The reverse-flow saphenous fasciocutaneous island flap in rabbit model was used. In group I (n=10), epidural catheterisation of the rabbits were performed and they received an epidural infusion of 0.1 ml kg(-1) 0.125% bupivacaine 12-h periods until the 10th day. In group II (n=10), epidural catheterisation of the rabbits was performed and they received an epidural infusion of 0.1 ml kg(-1) isotonic sodium chloride solution. In group III (n=10), epidural catheterisation of the rabbits was not performed. Intra-arterial blood pressure (IABP) and intravenous blood pressure (IVBP) was recorded at time intervals of 5, 15, 30 and 60 min, respectively, after tourniquet release on the first and 10th day. Microcirculatory flow was measured by laser Doppler flowmetry at 2, 4, 6, 8 and 10 days in all the groups.

RESULTS

Throughout the experiment, the flaps showed complete survival. A significant difference was noted in the microcirculatory flow measurements in the flap surfaces between group I and groups II-III throughout the experiment (p<0.05). A significant difference was noted in IVBP and IABP between group I and groups II-III (p<0.05). On the first and the 10th day, however, there were no significant differences between groups II and III (p>0.05).

CONCLUSION

EA improves blood flow to RFFF and prevents the progression of venous congestion.

Effect of Venous Superdrainage on a Four-Territory Skin Flap Survival in Rats

BACKGROUND

In a previous report, the authors demonstrated that distal arterial supercharging is more effective at increasing flap survival. There is no doubt of the benefit of arterial augmentation in flap surgery, but the effect of venous superdrainage is still controversial. The purpose of this study was to investigate how venous augmentation could generate larger flap survival areas with different superdrainage positions in rats.

METHODS

A four-territory skin flap, developed by the authors, was used. Forty rats were divided into four groups, as follows: group 1, flaps based only on the deep circumflex iliac artery and vein; group 2, flaps superdrained with the ipsilateral superficial inferior epigastric vein; group 3, flaps superdrained with the contralateral superficial inferior epigastric vein; and group 4, flaps superdrained with the contralateral deep circumflex iliac vein. On the fourth postoperative day, the flaps were assessed by measurements of necrosis and survival areas. Vascular changes produced by venous augmentation were evaluated angiographically.

RESULTS

Compared with group 1 (mean flap survival, 37.8 +/- 5.0 percent), the flap survival areas were significantly greater in the superdrainage flap groups (group 2, 57.4 +/- 6.5 percent, p < 0.001; group 3, 72.4 +/- 21.3 percent, p < 0.001, and group 4, 89.2 +/- 18.8 percent; p < 0.001). Angiographic assessment of the flaps revealed dilatation of the choke vein between the territories and reorientation of dilated veins along the long axes of the flaps.

CONCLUSIONS

This study demonstrates that venous augmentation is also effective for increasing flap survival, and the distal procedure is more effective than the proximal procedure in arterial supercharging.

A reverse-flow composite flap in the rat

Reverse-flow flaps are currently particularly used for the reconstruction of defects of the distal part of the extremities. Despite their common usage there have been many reports of postoperative complications, especially resulting in partial or total flap necrosis. There is insufficient knowledge of flap haemodynamics, physiology and wound healing properties in reverse-flow flaps. Development of the proper experimental models is needed to investigate these issues. The purpose of this study was to describe a new reverse-flow flap model in the rat. A total of 20 adult Wistar rats weighing 200-250 g were used in this experiment. In five rats, the vascular anatomy of the auricle of the rat was determined by anatomic dissection and microangiography. In the experimental group (N=5), 1x1 cm reverse-flow composite flaps were harvested as a semi-island shape, based on the distal course of the medial branch of the anterior auricular artery. In the control group, consisting of five rats, the flap was designed and raised based on the proximal course of the medial auricular artery, again in a semi-island shape. In the remaining five animals, a square-shaped composite tissue of the whole layer of the auricle, 1x1 cm in size, was harvested dividing all the bases circumferentially. The composite tissue was replaced in situ. While the former was considered a conventional antegrade-flow flap subgroup, the latter was designated as a graft subgroup. All flaps were replaced in situ. The survival of the flap was evaluated on postoperative day 7 by direct observation and microangiography. The skin island of all the reverse-flow flaps and conventional antegrade-flow flaps survived completely giving a success rate of 100%, whereas all grafts in the control group underwent complete necrosis. Microangiographic studies revealed the vascularity of the reverse-flow and antegrade-flow flaps, identifying the course of the auricular arteries. In conclusion, with its evident advantages of easy to design and harvesting, reliable survival pattern and consistent vascular structure, our new flap model will provide a means for future studies on flap haemodynamics, physiology in reverse-flow flaps.

The lateral supramalleolar flap: experience with 41 flaps

The lateral supramalleolar flap was used in 41 cases of distal third of the leg, foot, ankle, and heel skin defect reconstruction. The arterial blood supply was mixed in 33 cases and retrograde in 8 cases. The authors recommend raising a distal subcutaneous pedicle to avoid skin grafting over the tendons. In main cases of mixed blood supply, the superficial peroneal nerve could be spared. Eight venous congestions were observed, including 3 with partial flap necrosis. The plastic result was assessed as satisfactory in all but 2 patients. The cosmetic aspect was satisfactory in only 6 patients. Donor site morbidity was minimal, while cosmetic results were assessed as satisfactory in all but 2 patients. The main local alternative was the distally based sural flap, which is technically less demanding. Except for the distal coverage of the foot, indications for both flaps are similar. The distally based sural flap requires the sural nerve to be divided and does not cover as distally as the lateral supramalleolar flap.

Immediate use of medicinal leeches to salvage venous congested reverse pedicled neurocutaneous flaps

Reverse pedicled neurocutaneous flaps have recently become popular for reconstructing soft tissue defects of the lower extremity. Venous congestion is a relatively common problem in these flaps in diabetic patients and those with electric burns, and this may cause partial or complete loss if capillary perfusion is not re-established urgently. We describe our experience of 13 neurocutaneous flaps, of which five developed venous congestion and were treated successfully with leeches placed immediately.

Comparison of different managements of large superficial veins in distally based fasciocutaneous flaps with a veno-neuro-adipofascial pedicle: An experimental study using a rabbit model

The role of large superficial veins in the survival of a distally based fasciocutaneous flap with a veno-neuro-adipofascial pedicle was studied in a rabbit model. A sural veno-neuro-fasciocutaneous flap model (6 x 2 cm) with a distally based lesser saphenous veno-neuro-adipofascial pedicle (1.5 cm) was established. Fifteen rabbits were randomly divided into three groups with 10 flaps in each group. In group I, the distal lesser saphenous vein was left open (venous inflow remained) after the flap was raised. In group II, the lesser saphenous vein was ligated in the pedicle (no venous inflow). In group III, the venous pedicle was left open in the pedicle, and the proximal end was microsurgically anastomosed to the recipient vein (outflow established). Intravenous pressure, flap survival, and histology were examined. The results showed that the values of intravenous pressure in group I were significantly higher than in group II (P < 0.001). The mean flap survival rate of group III (94.5%) was significantly higher (P < 0.001) than of groups I (22.7%) and II (55.5%). Histology showed that the lesser saphenous vein in group I was extremely dilated and filled with thrombosis. This experiment demonstrated that establishing a superficial venous outflow channel by anastomosis at the proximal end, or interrupting the inflow channel by ligation at the distal pedicle, may significantly improve the survival rate of distally based veno-neuro-fasciocutaneous flaps.

Comparison of venous drainage in reverse-flow island flaps: an experimental study of the rabbit saphenous fasciocutaneous flap

The mechanism of venous drainage in reverse-flow island flaps was investigated using the saphenous fasciocutaneous flap in New Zealand White rabbits. Ten animals were allocated into two groups of 10 flaps. In group I (left limb), the distal vascular pedicle (one saphenous artery and two venae comitantes) was not disturbed, maintaining the communicating and collateral branches intact. In group II (right limb), it was separated microsurgically from each other for 3 cm. Intravenous pressure was measured at 5, 15, 30, and 60 minutes after tourniquet release. The values of group II at 30 and 60 minutes were significantly lower (p<0.01) than those of group I. Ten days after flap elevation, the mean survival area of group I (95%) and group II (100%) was not significantly different. Histological examination of the vascular pedicle showed the saphenous veins in group II were more dilated than those of group I. These findings suggest that venous retrograde return in reverse-flow island flaps can be achieved more easily through a "direct incompetent valves route" than through a "circuitous communicating and collateral bypass route."

[Venous drainage in retrograde pedicle flaps: experimental study in rats]

This study was performed to investigate the venous drainage in reverse island groin flaps in a rat model. Two groups of 10 rats were studied. All rats of group A had a groin reverse flap with a complete pedicle (artery and venae comitantes). In rats of group B, an arterial groin reverse flap (artery without venae comitantes) was performed. For the two groups, the perivascular tissue was excised. Nine flaps in the group A and seven flaps in the group B, survived without partial or complete necrosis. Microscopic examination showed venous dilatation in the two groups. There was no significant difference between the two groups. These results confirm that venous drainage of the arterial reverse flow flap without venae comitantes is performed by venae arteriosa. However, venae comitantes probably ensure venous drainage when they are respected.

The free thoracoumbilical flap for resurfacing large soft-tissue defects of the lower extremity

Both cadavers and living patients were studied regarding a method to resolve large skin defects with bone exposure in the leg, with long-distance thrombosis of the anterior tibial vessels or posterior tibial vessels resulting from traumatic lesions. Forty-six casting mold specimens of cadaveric legs were investigated. There were rich communication branches among the anterior tibial artery, posterior tibial artery, and fibular artery in the foot and ankle, which complemented each other well. Twenty-six patients with large skin defects with bone exposure in the proximal or middle segment of the leg were admitted to the authors' hospital. Among those patients, 19 demonstrated long-distance thrombosis of the anterior tibial vessels or posterior tibial vessels resulting from traumatic lesions. During treatment, a thoracoumbilical flap based on the inferior epigastric vessels was anastomosed to the distal stump of the anterior tibial vessels or the posterior tibial vessels, with reversed flow. All defects were successfully repaired, with good color and texture matches of the flaps. This method can be used for patients with normal anterior tibial vessels or posterior tibial vessels, normal distal stumps of the injured blood vessels, and good reversed flow. The method has the advantages of dissecting blood vessels in the recipient area during the débridement, not affecting the blood circulation of the injured leg, not sacrificing blood vessels of the opposite leg, and not fixing the patient in a forced posture. The muscles are less bulky in the distal one-third of the leg, and the blood vessels are shallow and can be dissected and anastomosed easily. When the flap is used for reconstruction in the proximal two-thirds of the leg, the blood vessel pedicle of the free flap is at a straight angle, without kinking.

Cutaneous anthrax of the hand and its reconstruction with a reverse-flow radial forearm flap

Bacillus anthracis infection can lead to necrosis in tissues and may manifest as a fatal disease in human beings. The authors present a patient with a large area of skin necrosis on the dorsum of the hand that was reconstructed with a reverse flow-through radial forearm flap, and they discuss the relevant literature. To the authors' knowledge, this is the first published report of such extensive necrosis resulting from anthrax limited to the extensor retinaculum of the hand.

[The supramalleolar flap. Our experience in 35 cases]

The authors report 35 cases of use of the supramalleolar flap described by Masquelet et al. in 1988. In 27 cases, the arterial blood supply was in a mixed (anterograde and retrograde) fashion since the perforating branch of the peroneal artery was spared. In eight cases the arterial blood supply was in a retrograde fashion due to the location of the skin loss. As described by Valenti et al. In 1991, the authors recommend the use of a distal subcutaneous pedicled to avoid skin grafting over the tendons at the distal part of the lag. In main cases of anterograde blood supply the superficial peroneal nerve could be spread. In 33 cases the plastic result was assessed as satisfactory. The coverage of the weight-bearing portion of the heel was done two times with no satisfactory result. Coverage of the medial malleolus area, Achilles tendon and dorsal skin of the foot represent the main indications and the best results. Five times, a venous congestion was observed with three cases of partial necrosis of the flap. The use of a large subcutaneous pedicle did not always prevent such venous problems, though this technical aspect improves the vascular reliability of the flap. The main local alternative is the distal pedicled sural flap that needs to divide the sural nerve and not allows coverage as distal as the supramalleolar flap. Except the distal coverage of the foot, the indications of these previous both flaps are similar. In case of foot coverage, the medial plantar flap based on the lateral plantar vascular bundle, as described by Martin et al. in 1991, is the other one local alternative. Free flaps are indicated for extensive skin losses, or when a poor distal vascularity of the leg does not allow reliability of distal pedicled flaps.

Venous drainage of the distally based lesser saphenous-sural veno-neuroadipofascial pedicled fasciocutaneous flap: a radiographic perfusion study

The drainage pathway of the distally based lesser saphenous-sural veno-neuroadipofascial pedicled fasciocutaneous flap using accompanying arteries of the lesser saphenous vein and sural nerve as nutrient vessels of the flap was radiographically investigated using five fresh cadavers. Small long veins existed along the lesser saphenous vein, and they were considered to be concomitant veins of the accompanying arteries of the lesser saphenous veins. They anastomosed with the lesser saphenous vein in some places and played a role in bypassing valves in the lesser saphenous vein.