Successful delayed venous drainage in 16 consecutive distal phalangeal replantations

The authors describe, in the first report of this type of replantation surgery, a high success rate using delayed venous anastomosis in 16 consecutive distal phalangeal replantations under digital block. Among these replantations, seven fingers (43.8 percent) showed postoperative venous congestion and five fingers were reoperated on with delayed venous drainage under digital block. All the reoperated fingers were successfully drained by additional single or double venous drainage with a vein graft. As a result, 13 fingers survived (81.3 percent success rate). All operations were performed under a digital block.     

The timing of neovascularization in fingertip replantation by external bleeding

To overcome venous congestion in fingertip replantation with no venous anastomosis, the authors have used a salvage procedure that consists of continuous external bleeding through a stab incision on the paraungual area and dripping a heparinized saline solution at the incision site to maintain external bleeding. Because this method requires continuous bleeding for a certain period of time, it may be a great burden on the patient; therefore, it is most important to minimize the duration of bleeding. Many authors have studied the timing of the new venous channel formation of the flap. However, to our knowledge, a study on fingertip replantations has not yet been performed. From June of 1985 to November of 1999, the authors performed fingertip replantations on 144 fingers of 137 patients using our salvage procedure at Korea University Guro Hospital. Among the 144 fingers, 101 fingers of 96 patients were successfully transplanted, including those with partial necrosis. The authors reviewed the medical records of these 101 fingers retrospectively; they compared and analyzed the necessary duration of external bleeding according to sex, age, level of injury, cause of amputation, and the type of injury. The average period of the salvage procedure was 7.6 days. Regarding age, the shortest period (5.5 days) was required for patients younger than 10 years. On the basis of the types of injuries, the duration of bleeding was shortest for the guillotine injury group (5.9 days) compared with crush (8.2 days) or avulsion (8.0 days) injuries. Sex and level of injury did not make much difference in the duration of the procedure.     

The optimal sequence of microvascular repair during prolonged clamping in free flap transfer

During free flap transfer, the surgeon may decide to begin with repair of the artery or the vein(s) and to unclamp the first vessel as soon as repair is completed or maintain the clamping of both vessels until completion of all repairs. Complications can lead to prolonged clamping times, potentially increasing the risk of tissue ischemia, vascular damage, and thrombosis. The goals of the present study were to determine whether the sequence of vessel repair and the duration of clamping affect the success of free flap transfer in cases requiring prolonged clamping. Sixty abdominal fasciocutaneous free flaps based on the superficial inferior epigastric vessels were created in Sprague-Dawley rats. To model clinical situations in which prolonged clamping is necessary, the study used a 1-hour delay before the repair of the second vessel. Flaps were randomized into four groups. In group I (n = 15), the artery was repaired first, and the arterial clamp was removed immediately to allow arterial inflow. In group II (n = 15), the arterial repair was first, and the arterial clamp was maintained until completion of venous repair. In group III (n = 15), venous repair was first, with venous clamping maintained until completion of the arterial repair. In group IV (n = 15), initial venous repair was followed by immediate unclamping, before arterial repair. On release of all clamps, the patency of arteries and veins was confirmed immediately and after 1 hour using a "milking" test. On the fifth postoperative day, each flap was assessed for necrosis and for patency of the anastomoses. Of 15 flaps in each group, five (33 percent) failed in group I, four (27 percent) failed in groups II and III, and six (40 percent) failed in group IV. Differences between groups were not statistically significant (p = 0.8). These results demonstrate that in cases requiring prolonged occlusive clamping (2 to 3 hours), factors such as venous congestion, possible clamp injury, and presence of static blood in contact with the new anastomosis have relatively equivalent contributions to the risk of failure. Accordingly, no advantage seems to be gained by beginning with the artery or the vein or by using early or delayed unclamping of the first vessel repaired.     

Fingertip replantation using the subdermal pocket procedure

Restoration of finger length and function are the goals of replantation after fingertip amputation. Methods include microsurgical replantation and nonmicrosurgical replantation, such as composite graft techniques. To increase the survival rates for composite grafts, the subcutaneous pocket procedure has been used as a salvage procedure. The subdermal pocket procedure, which is a modification of the subcutaneous pocket procedure, was used for replantation of 17 fingertips in 16 consecutive patients. Eight fingertips experienced guillotine injuries and the other nine fingertips experienced crush injuries. Revascularization of one digital artery without available venous outflow was performed for six fingers, and composite graft techniques were used for the other 11 fingers. The success rate was 16 of 17 cases. The difference in success rates for guillotine versus crush injuries was statistically significant. Comparison of patients with arterial anastomoses and patients without arterial anastomoses also indicated a statistically significant difference. Thirteen fingertips survived completely. One finger, demonstrating complete loss and early termination of the pocketing procedure, was amputated on the eighth postoperative day. Two fingers were partially lost because of severe crushing injuries. One finger demonstrated partial loss of more than one quarter of the fingertip, which required secondary revision, because the patient was a heavy smoker. The pocketing period was 8 +/- 1 days (mean +/- SD, n = 6) for the fingers revascularized with one digital arterial anastomosis and 13.3 +/- 1.9 days (n = 10) for the fingers successfully replanted with composite graft techniques. The mean active range of motion of the interphalangeal joint of the three thumbs was 65 +/- 5 degrees, and that of the distal interphalangeal joint of the other 11 fingers was 51 +/- 11 degrees. The static two-point discrimination result was 6.4 +/- 1.0 mm (n = 14) after an average of 11 +/- 5 months of follow-up monitoring. Compared with other methods, the subdermal pocket procedure has the advantages of exact subdermal/subdermal contact, a shorter pocketing period, and more feasible observation. The method can offer an alternative salvage procedure for fingertip amputations with no suitable vessels available for microsurgical replantation.     

Microsurgical replantation of the amputated nose

A case of successful replantation of the nose is presented. Two arteries and one vein were anastomosed, providing a stable framework for direct revascularization of the amputated nasal segment. This resulted in complete survival of the nose, with an excellent aesthetic result. However, despite successful microsurgical arterial and venous repair, significant postoperative blood loss still occurred as a result of anticoagulation. In cases of the amputation of specialized structures, the improved functional and cosmetic result obtained with replantation must be weighed against the risk of blood-borne disease transmission when postoperative transfusion is required. Recognizing the potential need for postoperative transfusion in these cases is important in allowing the surgeon to exercise appropriate judgment in deciding whether replantation should be performed.     

The use of arteriovenous anastomosis for replantation of the distal phalanx of the fingers.

Microvascular replantation at the distal phalangeal level has recently been reported by several authors, but as yet the rate of success has not been constant owing to the technical difficulties associated with small vessels. To solve this problem, over the last 4 years we have used arteriovenous anastomosis to reestablish either the arterial system or the venous drainage system in the 33 digits of our 23 patients. The results have been excellent, with a 91 percent success rate. Such results for replantation of the distal phalanx may be maintained and improved if a small venous graft with several branches is also utilized.     

A new technique for microvascular anastomosis: external metallic circle

Vessel anastomosis is the most critical step in free tissue transfers and replantation surgery. We report on a new microvascular anastomosis technique that uses a metallic circle around the anastomotic circumference. Sutures are first passed inside the circle and tied outside and over the circle so as to stretch open the anastomotic site. By retraction of vessel ends, the circle is totally exteriorized and thus there is no contact with blood. In 48 rats, the external circle method was compared with the conventional technique for constructing end-to-end anastomosis between carotid arteries (1 to 1.2 mm) and femoral veins (1 to 1.5 mm). The external circle method proved to be superior to the conventional end-to-end technique in speed of execution for both arterial and venous anastomoses. Patency rates at the third week were significantly higher in the venous group using the metallic circle (100 percent versus 70.8 percent, p < 0.05). This new method may be applicable in clinical microvascular surgery.     

The role of the large superficial vein in survival of proximally based versus distally based sural veno-neuro-fasciocutaneous flaps in a rabbit model

A sural veno-neuro-fasciocutaneous flap in the New Zealand White rabbit was developed, and the role of the large subcutaneous lesser saphenous vein was investigated in proximally based versus distally based flaps. Retrograde dye injection showed that the lesser saphenous vein in rabbits has many valves with strong resistance against reflux. Twenty rabbits were randomly allocated into four groups of 10 flaps each. Group I consisted of proximally based flaps with the lesser saphenous vein intact (outflow) in the veno-neuro-adipofascial pedicle. Group II also consisted of proximally based flaps but the lesser saphenous vein was ligated at 1 cm proximal to the pedicle. Group III consisted of distally based flaps with the lesser saphenous vein intact (inflow) in the veno-neuro-adipofascial pedicle. Group IV also consisted of distally based flaps, but the lesser saphenous vein was ligated at 1 cm distal to the pedicle. The results showed that the mean flap survival area in group I (88.8 percent) was statistically higher than that in group II (62.6 percent, p < 0.001), and was higher in group IV (55.5 percent) than in group III (22.7 percent, p < 0.01). However, group II and group IV had no significant difference (p > 0.05). This experiment demonstrated that flap viability is determined by its intrinsic vascularization, both arterial and venous. The large superficial subcutaneous vein has a positive role (venous outflow) in proximally based flaps but a negative role (venous inflow) in distally based flaps. If the effect of the large subcutaneous vein is excluded, distally based flaps are not inherently inferior to proximally based flaps.     

Flap perfusion after free musculocutaneous tissue transfer: the impact of postoperative complications

In a previous study, the authors found persistence of pedicle blood flow up to 10 years after uncomplicated free latissimus dorsi transfer. In this study, the impact of postoperative complications (hematoma, thrombosis, infection) and successful surgical revision was tested. Since 1982, more than 1200 free tissue transfers have been performed at the authors' institution (Hannover Medical School). Of these, the authors selected two groups of 30 patients each who had received a free latissimus dorsi transfer to the lower leg without microsurgical nerve coaptation for wound coverage. All patients included in this study were carefully selected for clinical homogeneity, with one difference: group I comprised patients who had no postoperative complications after free latissimus dorsi transfer. Group II included only patients with major postoperative complications after the procedure. All flaps in group II survived after successful surgical revision. The arteries, which nourished the lower leg, were visualized and documented by means of a duplex scanner in both groups. Three different time intervals were chosen for measurements of blood flow: 4 to 6 months (groups I.I and II.I), 4 to 6 years (groups I.II and II.II), and 8 to 10 years (groups I.III and II.III). Quantitative measurements of local flap perfusion in milliliters per minute per 100 g tissue were performed by means of the hydrogen clearance technique. In each patient, a total of nine measurements was performed in three phases: phase A, before closing the vascular pedicle by manual compression (n = 3); phase B, with a closed pedicle (n = 3); and phase C, after releasing the vascular pedicle from manual compression (n = 3). Each measurement took approximately 10 minutes. One hundred percent closure of each pedicle in phase B was confirmed by the duplex scanner. Furthermore, all patients were monitored both clinically and by means of the hydrogen clearance technique during phase B for adequate blood supply to the lower leg. Lower leg perfusion showed no statistical differences for phases A, B, and C in all groups of patients. In group I, no statistical differences in local flap perfusion were encountered for phases A and C. In phase B, however, a statistically significant (p < 0.01) complete extinction of local flap perfusion was registered in all patients of group I at the site of the flap's skin paddle. In group II, however, persistent flap perfusion was registered during phase B in up to 50 percent of cases in one subgroup (II.III). No statistically significant alterations of local blood flow were registered in the surrounding tissue of group II during phases A, B, and C. Patients with thrombosis of the venous anastomosis (n = 7) seemed to have the highest incidence of loss of autonomous blood supply through the vascular pedicle (5 out of 11 cases). No inconstant results were found during the repetitive measurements (n = 3) for each patient in each phase. After uncomplicated free tissue transfer, the flap's intact vascular pedicle seems to play an important role in permanent flap survival up to 10 years after the procedure. Postoperative complications after free tissue transfer with successful surgical revision, especially venous thrombosis of the vascular anastomosis, may lead to loss of vascular flap autonomy over time.     

A new strategy of fingertip reattachment: sequential use of microsurgical technique and pocketing of composite graft

Many methods have been used to reattach amputated fingertips. Of these methods, microsurgery has been accepted as the procedure of choice because the defining characteristic of a microsurgically replanted finger is that its surival in the recipient bed is predicated on functioning intravascular circulation. Although considerable progress has been made in the techniques for microvascular replantation of amputated fingers, the replantation of an amputated fingertip is difficult because digital arteries branch into small arteries. This is in addition to digital veins that run from both sides of the nail bed to the median dorsal sides, which are difficult to separate from the immobile soft tissue. Furthermore, even with the most technically skilled microsurgeon, replantation failure often occurs, especially in severe injury cases. Therefore, the technique is not the only protection against failure, and a new strategy of fingertip reattachment is needed. From March of 1997 to December of 1999, 12 fingers of 11 patients with zone 1 or zone 2 fingertip amputations that were reattached microsurgically but were compromised were deepithelialized, reattached, and then inserted into the abdominal pocket. All had been complete amputations with crushing injuries. Approximately 3 weeks later, the fingers were depocketed and covered with a skin graft. Of the 12 fingers, 7 survived completely and 3 had partial necrosis on less than one-third the volume of the amputated part. The complete survival rate was approximately 58 percent. The results of the above 10 fingers were satisfactory from both functional and cosmetic aspects. The authors believe that this high success rate was achieved because the deepithelialized finger pulp was placed in direct contact with the deep abdominal fascia, which was equipped with plentiful vascularity, not subcutaneous fat. In addition, the pocketing was performed promptly before necrosis of the compromised fingertip occurred. From the results of this study, it is clear that this new method is useful and can raise the survival rate of an amputated fingertip.     

Two replantations of severed ear parts.

Two successful cases of replantation of part of an ear are presented; both were done by simple suture. The larger of these replants consisted of a 13 x 43 mm segment of the superior helix and concha. Both were vascularized beofre 48 hours. The greatest problem was venous congestion. In the larger replant we made multiple puncture wounds daily on both sides of the graft with an 18-gauge needle to help relieve this.     

A 10-year retrospective review of 758 DIEP flaps for breast reconstruction

This study examined 758 deep inferior epigastric perforator flaps for breast reconstruction, with respect to risk factors and associated complications. Risk factors that demonstrated significant association with any breast or abdominal complication included smoking (p = 0.0000), postreconstruction radiotherapy (p = 0.0000), and hypertension (p = 0.0370). Ninety-eight flaps (12.9 percent) developed fat necrosis. Associated risk factors were smoking (p = 0.0226) and postreconstruction radiotherapy (p = 0.0000). Interestingly, as the number of perforators increased, so did the incidence of fat necrosis. There were only 19 cases (2.5 percent) of partial flap loss and four cases (0.5 percent) of total flap loss. Patients with 45 flaps (5.9 percent) were returned to the operating room before the second-stage procedure. Patients with 29 flaps (3.8 percent) were returned to the operating room because of venous congestion. Venous congestion and any complication were observed to be statistically unrelated to the number of venous anastomoses. Overall, postoperative abdominal hernia or bulge occurred after only five reconstructions (0.7 percent). Complication rates in this large series were comparable to those in retrospective reviews of pedicle and free transverse rectus abdominis musculocutaneous flaps. Previous studies of the free transverse rectus abdominis musculocutaneous flap described breast complication rates ranging from 8 to 13 percent and abdominal complication rates ranging from 0 to 82 percent. It was noted that, with experience in microsurgical techniques and perforator selection, the deep inferior epigastric perforator flap offers distinct advantages to patients, in terms of decreased donor-site morbidity and shorter recovery periods. Mastery of this flap provides reconstructive surgeons with more extensive options for the treatment of postmastectomy patients.     

Replantation of fingertip amputation by using the pocket principle in adults

There are several treatment modalities for zone 1 or zone 2 fingertip amputations that cannot be replanted by using microsurgical techniques, such as delayed secondary healing, stump revision, skin graft, local flaps, distant flaps, and composite graft. Among these, composite graft of the amputated digit tip is the only possible means of achieving a full-length digit with a normal nail complex. The pocket principle can provide an extra blood supply for survival of the composite graft of the amputated finger by enlarging the area of vascular contact. The surgery was performed in two stages. The amputated digit was debrided, deepithelialized, and reattached to the proximal stump. The reattached finger was inserted into the abdominal pocket. About 3 weeks later, the finger was removed from the pocket and covered with a skin graft. We have consecutively replanted 29 fingers in 25 adult patients with fingertip amputations by using the pocket principle. All were complete amputations with crushing or avulsion injuries. Average age was 33.64 years, and men were predominant. The right hand, the dominant one, was more frequently injured, with the middle finger being the most commonly injured. Of the 29 fingers, 16 (55.2 percent) survived completely and 10 (34.5 percent) had partial necrosis less than one-quarter of the length of the amputated part. The results of the above 26 fingers were satisfactory from both functional and cosmetic aspects. Twenty of the 29 fingers, which had been followed up for more than 6 months (an average of 16 months), were included in a sensory evaluation. Fifteen of these 20 fingers (75 percent) were classified as "good" (static two-point discrimination of less than 8 mm and normal use). From the overall results and our experience, we suggest that the pocket principle is a safe and valuable method in replantation of zone 1 or zone 2 fingertip amputation, an alternative to microvascular replantation, even in adults.     

Successful replantation in the face of absent venous drainage: an experimental study

Inadequate venous outflow is the factor most responsible in digital replantation failure and is a common cause of tissue loss in general. An experimental replantation model utilizing the rabbit ear was used to study the extreme example of venous congestion: absent venous drainage in the replanted part. Results of this study support the use of single arterial inflow along with an efferent AV fistula for outflow in the management of replants with absent venous drainage. Potential indications for the use of an efferent arteriovenous fistula in digital revascularization include the following: (1) the finding of distal veins too small to reanastomose, as is often the case in children and at distal levels in adults; (2) preferential destruction of distal venous structures, as commonly seen in degloving or other dorsal injuries; and (3) in the management of postreplant venous thrombosis.     

Avulsion injuries of the thumb

Avulsion amputations of the thumb are generally thought to have a worse prognosis after replantation than other amputations. We report the results of 17 thumbs that had an avulsion amputation and were replanted. Fourteen of the 17 survived (82 percent). Our experience indicated that the survival rate was improved by restoring continuity of at least two veins and two arteries, using a Y-shaped vein graft and the princeps pollicis artery for the source of arterial circulation. Nerve grafts were used to bridge defects in avulsed digital nerves. When possible, avulsed tendons were reattached to their muscle. Key pinch strength was 60 percent of normal, and grip strength was always less than that of the normal hand. The age of the patients and the cold ischemia time had no significant effect on either survival or function of the replanted thumb. When excellent venous backflow occurred immediately after the vessel repair and continued for at least 20 minutes, the thumb always survived without complications.     

Survival and blood flow evaluation of canine venous flaps

Using a canine model, we compared postoperative viability of saphenous venous flaps, cephalic venous flaps, and composite-tissue grafts without vascular connections. Of the saphenous flaps, 14 percent survived. Of the flaps based on the cephalic vein, 75 percent survived. Cephalic composite-tissue grafts were 13 percent successful. The presence of a more intricate venous plexus in a flap seems to increase its chances of success. Arterial injections of radioisotope-labeled microspheres were used to chart revascularization in cephalic flaps. These flaps demonstrated arterial blood flow by day 3, while the composite grafts showed no flow until day 7. Venous injections of microspheres distal to the flap were used to test vein-to-capillary blood flow. No significant entrapment of microspheres within the flaps occurred at any time, suggesting such flow to be inadequate.     

Venous congestion and blood flow in free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps

A series of 240 deep inferior epigastric perforator (DIEP) flaps and 271 free transverse rectus abdominis myocutaneous (TRAM) flaps from two institutions was reviewed to determine the incidence of diffuse venous insufficiency that threatened flap survival and required a microvascular anastomosis to drain the superficial inferior epigastric vein. This problem occurred in five DIEP flaps and did not occur in any of the free TRAM flaps. In each of these cases, the presence of a superficial inferior epigastric vein that was larger than usual was noted. It is therefore suggested that if an unusually large superficial inferior epigastric vein is noted when a DIEP flap is elevated, the vein should be preserved for possible use in flap salvage. Anatomical studies with Microfil injections of the superficial venous system of the DIEP or TRAM flap were also performed in 15 cadaver and 3 abdominoplasty specimens to help determine why venous circulation (and flap survival) in zone IV of the flaps is so variable. Large lateral branches crossing the midline were found in only 18 percent of cases, whereas 45 percent had indirect connections through a deeper network of smaller veins and 36 percent had no demonstrable crossing branches at all. This absence of crossing branches in many patients may explain why survival of the zone IV portion of such flaps is so variable and unpredictable.     

Mechanical anastomosis of small arteries and veins with the unilink apparatus: a histologic and scanning electron microscopic study

A new method for mechanical anastomosis of small vessels--the Unilink device--has been tested in 23 rabbits. A total of 81 arterial and venous anastomoses were performed. One of the arterial anastomoses were thrombotized, while the remaining 80 anastomoses were fully patent at 2 or 16 weeks. The repair process at the anastomotic site was very rapid both in arteries and veins. The endothelialization was complete at 2 weeks, but a marked atrophy of the media was noted in the arterial anastomoses. The same phenomenon was observed in the venous anastomosis, but to a much lesser degree. Thrombus formation was extremely rare, and the atrophy of the media did not seem to affect the patency rate. The experiment has confirmed that the Unilink method provides a very safe, fast, and simple way to perform microvascular anastomoses.     

Influence of venous emptying on the reactive hyperemic blood flow response

Background

Previous research indicates that venous emptying serves as a stimulus for vasodilation in the human forearm. This suggests the importance of recognizing the potential influence of venous volume on reactive hyperemic blood flow (RHBF) following occlusion. The purpose of this study was to examine the influence of venous emptying on forearm vascular function.

Methods

Forearm RHBF, venous capacitance and venous outflow were examined in 35 individuals (age = 22 ± 2 years), using mercury in-Silastic strain gauge plethysmography, at rest and following five minutes of upper arm occlusion using standard procedures (Control). In addition, the same measures were obtained following five minutes of upper arm occlusion preceded by two minutes of passive arm elevation (Pre-elevation).

Results

Average resting arterial inflow was 2.42 ± 1.11 ml·100 ml^-1·min^-1. RHBF and venous capacitance were significantly greater during Pre-elevation compared to Control (RHBF; Pre-elevation: 23.76 ± 5.95 ml·100 ml^-1 ·min^-1 vs. Control: 19.33 ± 4.50; p = 0.001), (venous capacitance; Pre-elevation: 2.74 ± 0.89 % vs. Control: 2.19 ± 0.97, p = 0.001). Venous outflow did not differ between the two conditions.

Conclusion

Venous emptying prior to upper arm occlusion results in a significant greater RHBF response and venous capacitance. Recognition of the influence of venous volume on RHBF is particularly important in studies focusing on arterial inflow, and also provides further evidence for the interplay between the venous and arterial system.