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Microvascular surgery in children
British Joumal of Plastic Surgery (1991), 44.276-280 0 1991 The Trustees of British Association of Plastic Surgeons
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Microvascular surgery in children V. S. Devaraj, S. P. Kay, A. G. Batchelor and A. Yates Department of Plastic Surgery, St. James’s University Hospital, Leeds SUMMARY. 43 microvascular procedures were performed in 38 children, (age limit 15 years) over a three year period. The average age was 5.4 years. The majority of the procedures were elective (63%), the remainder urgent or emergency. The overall vascular success rate was 93%, confirming previous reports. Three failures were observed, 2 of these being thumb avulsion iqiuries, the third a free-flap. Two patients underwent re-exploration of the anastomosis with successful outcomes. Vessel size was not a problem and generally exceeded 0.8 mm external diameter. The total time under anaesthetic averaged 5.5 hours, and postoperative recovery included monitoring and pain control on a High Dependency Unit. The average hospital stay was 10 days. The indications for surgery differ from those in adults, management is more complex, and includes the physical and psychosocial care of the child and parents. Despite raising certain anxieties in the past, microvascular surgery in childrenis safe, reliable and carries a high success rate.
Microvascular surgery began experimentally with the work of Jacobson and Suarez (1960). Clinical development quickly followed with reports by Kleinert and Kasdan (1962) of the first thumb revascularization, and by Komatsu and Tamai (1965) of the first thumb replantation. Since then the practice of microsurgery in adults has become well established with success rates exceeding 70%~88%. However despite an early report by Malt and McKhann (1964) who successfully replanted an arm severed at the mid-humeral level, in a 12 year old boy, there remained anxieties over the feasibility of microsurgery in small children. The indications for surgery were inherently different to those encountered in an adult population and there was an assumption that vessel sizes would defy successful anastomosis. Consequently early reports on microsurgery in children were sporadic. Harii and Ohmori (1975) reported free groin flaps in two children aged 4 years, and Ohmori et al. (1977) subsequently reported a successful free groin flap in a baby of three months. He suggested that there was no minimum age for free flap transfer. The donor artery (the common trunk of the superficial circumflex iliac and superficial epigastric arteries), was 0.9 mm and recipient vessel (radial artery), 1.Omm. Corresponding venae comitantes (both donor and recipient vessels) were 2.0 mm. Van Beek et al. (1979) reported eight successful microvascular replantations in children under 6 years with digital injuries. Excellent function, appearance and a maintained potential for growth were observed. The vessels were larger than expected from the child’s size. The same year, Sekiguchi and Ohmori reported on the youngest patient with a successful replantation aged 12 months and 15 days. In 1980, O’Brien et al. reported a series of 18 digital replantations and 13
revascularisations in 27 children with an average age of 6.8 years. The overall digit survival rate was 65% (20 digits), and three factors, the age of the child, the level of the injury and type of injury, influenced the likelihood of success. Thus, only half of the procedures were successful in children less than two years of age, compared with 70% in children over five. This was presumed to be due to the smaller vessel diameter and technically difficult repair. More proximal digital injuries were more likely to survive than distal ones, as were those without a significant element of diffuse crush/avulsion. Those authors emphasised that salvage of any amputated, or devascularised, digit or extremity in a child was worthwhile with favourable outcomes in terms of sensation, growth and function. Further reports supported these observations, (Jaeger et al., 1981, Black, 1982, Chicarilli, 1986). Gilbert (1985) reported 49 cases of second-toe to hand transfer in 38 patients (average age of 24 months), with a 98% success rate. Interestingly he felt that 0.7 mm diameter was the lower limit of safe vessel size for surgery. More recently, Parry et al. (1988) reported 22 elective free-tissue transfers in children aged 2-14 years, with a 96% success rate and only one flap failure. Similarly Lister (1988) has reported 100% survival in 12 toetransfers in children with an average age of two years. Clinical material 38 children had microvascular procedures over a 3year period at St. James’s University Hospital in Leeds. One of two consultant plastic surgeons performed each microvascular procedure. Arteriography was not routinely performed on children preoperatively and clinical examination and exploration were used for elucidating vascular anatomy. However one 276
Microvascular
277
Surgery in Children
13-year-old child with a large juvenile angiofibroma of the nasopharynx underwent preoperative angiography and embolization of the feeding vessels. A two year old child for hand reconstruction following meningococcal septicaemia also underwent angiography because of uncertainty over the extent of vessel obstruction. Toe-transfer for hand reconstruction in congenital deformity was undertaken in children between 10 months and 5 years. In these procedures the transfer was based upon the first cleft vessels of the foot, either the first dorsal metatarsal artery or the plantar system. Recipient vessels in limb microsurgery were axial, using either end-side or end-end anastomoses as appropriate. Suture size varied from 9/O to 10/O and (rarely) 11/O. Heparinised Hartmanns solution was used to irrigate the vessels prior to anastomosis. Both the donor and recipient vessel sizes were recorded (arteries and veins) immediately prior to anastomosis, and following gentle mechanical dilatation if appropriate. Anti-thrombic agents in the form of asprin, dipyridamole, heparin or dextran were not routinely used in this series. Surgery was performed under general anaesthetic supplemented with regional anaesthesia, usually via indwelling catheters to assist with postoperative pain relief. Intraoperative fluid replacement was primarily with colloid, (human albumin solution/Haemacell), or crystalloid. Blood transfusions were largely avoided. Many children had haemoglobin levels as low as 7 g/d1 postoperatively, with however increased or normal intravascular volumes, and thus no adverse sequelae. Postoperatively, depending on anaesthetic preference, the children were either admitted to an Intensive Care Unit (ICU) for elective ventilation, (more common after head and neck procedures), or extubated and transferred to a High Dependency Unit (HDU) for monitoring and pain control, following limb reconstruction. Central venous pressure, heart rate, blood pressure, core-peripheral temperature gradient and urine output were closely monitored as a guide to intravascular volume. Oxygen saturation, respiration rate and pupil reactivity were also monitored as nurse controlled opiate infusions were routine. In older children, Patient Controlled Analgesia systems (opiate infusions) were useful. A bupivacaine infusion through epidural or brachial plexus indwelling catheters assisted pain control. The children were maintained in a critical care environment (ITU or more commonly HDU) until opiates were discontinued and regional anaesthesia catheters removed.
RC?SUltS
Over a 36 month period, (1987-1990), 43 microvascular procedures were performed in 38 children, with an average age of 5.4 years. The youngest was a premature infant born at 28 weeks gestation and weighed under 1 kg. The oldest child was 15 years. Figure 1 illustrates the age distribution, and type of procedure.
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00
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.:
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4
5
6
7
a
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: 0
10 11 12 13 14 15
b
Age (Years) Fig.
Figure l-Age
1
distribution and type of
procedure.
The microvascular procedures performed in the series are summarised in Table 1, and the indications for surgery in Table 2. The case-mix differed from that associated with an adult population undergoing microvascular surgery, as the congenital hand deformities formed the largest single group. This included a child with constriction band syndrome illustrated in Figure 2. Table 1 children
The
microvascular
procedures
Free tlap Toe-transfer Replantation Revascularisation
Table 2
The indications
performed
in
22 14 4 3
for surgery
Congenital hand deformity Road traffic accident Bum Tumour Replant/Revascularisation Other
12 7 5 4 7 3
27 of the procedures were elective (63x), while 16 were either emergency or urgent, (37%). The donor sites used in the series are recorded in Table 3. A latissimus dorsi flap being raised in a 5-month-old child is shown in Figure 3. Both the donor and recipient vessel sizes were recorded (arteries and veins) immediately prior to anastomosis and ranged between 0.4-3.0 mm (external diameter) with an internal diameter exceeding 0.3 mm. The mean time under anaesthesia was 5.5 hours (range 2.5-9.5). The operative time was generally one hour shorter (4.5 hours). There were no unsuccessful procedures in those children undergoing elective microvascular surgery. Figure 4 illustrates a thumb reconstruction using a second toe-transfer, in the immediate postoperative period. Overall, 40 microvascular procedures were
278
British Journal of Plastic Surgery Table 4
The outcome of microvascular
surgery
No. of cases
Success
Failure
Elective Free-flaps Toe-transfers
13 14
13 14
0 0
Emergency Free-flaps Replantations Revasc.
9 4 3
8 2 3
1 2 0
Fig. 2 Figure 2-Congenital constriction band syndrome, in a 5-year-old. She underwent bilateral second toe-transfers.
Table 3
The donor sites used in the series Latissimus dorsi Lateral arm Scapular Rectus abdominis Fibular Second-toe Wrap-around toe flap
10 I 2 2 1 12 2 Fig. 4 Figure 4-A thumb reconstruction, using a second toe-transfer in a 2-year-old child with symbrachydactyly.
Fig. 3 Figure %A child.
latissimus dorsi flap being raised in a 5-month-old
successful (93x), and 3 failed (70/,). The outcome of the microvascular procedures performed is summarised in Table 4. The 3 failures (7”/,), included two replantations for crush/avulsion injuries of the distal thumb, both boys aged 6 and 11 years. Both children subsequently underwent successful thumb reconstructions using
wrap-around toe flaps, one as a delayed primary, the other as a secondary procedure. One latissimus dorsi free-flap failed in a 5-month-old baby due to irreversible venous thrombosis. This child had multiple congenital anomalies and was referred three weeks following primary surgery for club foot. The leg was severely injured and septic. Despite vein grafting to the popliteal fossa, we were unable to escape the zone of injury. Heparin injected directly into the flap, coupled with a systemic prostacyclin infusion failed to reverse the venous thrombosis in this infant, and reexploration was not helpful. Two other flaps in the series were re-explored, (reexploration rate 4.6%), and salvaged. One was a toetransfer in a 4-year-old which developed venous congestion on the night of surgery. At re-exploration, division of a tight skin bridge overlying the microvascular pedicle improved flap perfusion immediately. The other was an 8 year old undergoing a lateral arm free-flap which required revision of both arterial and venous anastomoses during the primary procedure as the vessels developed platelet thrombi. There was one minor complication, a small haematoma which developed in a lateral arm flap, 4 days post-operatively. The
Microvascular Surgery in Children
279
flap viability was not compromised and the haematoma removed without formal re-exploration. The overall mean post-operative stay was 9.8 days per microvascular transfer. This figure excluded two longer stays due to co-existant limb fractures, and unrelated to the microsurgery.
Discussion Microvascular surgery in children in our series carries a high overall success rate, (93%). There were no failures in the group of children undergoing elective microsurgery. In addition, there is a low complication rate (2x), confirming previous reports. The youngest patient to undergo a microvascular procedure, a baby born at 28 weeks gestation, represents the youngest patient on record. Davison and Sully (1988) previously advocated early microvascular surgery for ischaemia in the limbs of newborns in their report of a baby with a gestational age of 30 weeks. The baby in our series had a complete avulsion of the right common iliac artery during the removal of an aortic valvotomy catheter. FolIowing unsuccessful attempts at reanastomosis to the aorta including veingrafting, a femoro-femoral cross-over vein graft was performed. Initially this vein graft also became occluded but a streptokinase infusion improved limb vascularity, and the graft remained patent, with limb pulses demonstrably absent during digital occlusion of the extra-anatomic vein graft. The two other revascularisations were injuries to the brachial artery, sustained during cardiac catheterisation procedures in infants aged 3 weeks and 12 months. The younger child required a vein graft. The major indication for emergency microsurgery was trauma from road traffic accidents. Free tissue transfer provided a unique solution in crush or degloving injuries of the lower extremities, particularly feet, seen in 6 children, (Fig. 5). In this context, the latissimus dorsi flap was most commonly used, and anastomosed to the anterior tibia1 artery and either a venae commitans or superficial vein. Other authors have described similar experiences in children, (Iwaya et al., 1982, Banic and Wulff 1987). Both early and late reconstructive problems arose from bum injuries in 5 children. Late problems included adduction contracture in the first web space requiring release and resurfacing using the lateral arm free-flap. One three year old child sustained an extensive hand burn from an electric bar fire. This was debrided the day following injury and skin cover obtained with a free latissimus dorsi flap. He subsequently underwent a second toe-transfer. In two patients severe post-burn contractures of the neck were reconstructed using scapular flaps, one of which was tissue expanded prior to transfer. Good quality skin, colour match and an easily closed donor site were obtained. Two of the four tumours in the series, were rhabdomyosarcomas in children aged 8 and 13 years, one arising in the infra-temporal fossa, the other on the foot. The tumours were excised and the area resurfaced using a latissimus dorsi or a lateral arm flap
Fig. 5 Figure 5-A latissimus dorsi free flap used to resurface a severely injured foot and exposed ankle joint.
respectively. Similarly, the volume defects resulting from excision of a Ewing’s sarcoma in a maxillary antrum and a juvenile angiofibroma in a nasopharynx were filled using rectus abdominis free-flaps, in two children also aged 8 and 13 years. Two replantations of the four in the series failed. Both were thumb avulsion injuries that suffered postoperative venous occlusion. The two successful replantations included a 12 year old with a mid-forearm avulsion amputation. This patient also underwent a lateral arm free-flap some three weeks following replantation to provide additional skin cover to the hand. The smallest vessels anastomosed in this series were superficial (dorsal) veins with an external diameter of 0.4 mm in a child aged 2 years, who sustained an amputation through the proximal phalanx of an index finger, which was successfully replanted. Vessel size per se was not a limiting factor in this series, and the majority of vessels exceeded 0.8 mm external diameter, in keeping with previous reports. Similarly, as reported by Parry et aZ.-(1988), intraoperative vessel spasm was not a problem. The vessel lumen was usually pristine although this was not true of the failed free flap, where previous surgical trauma and sepsis had resulted in a friable and oedematous intimal lining. Postoperative ventilation overnight on an ICU ox extubation and transfer to a HDU allowed the main factors influencing vasospasm to be controlled i.e. cooling, intravascular volume, fear and pain. Infusion of bupivacaine, (0.1-0.25%), through a cannula in the sheath around the brachial plexus in upper limb microsurgery appeared to reduce the requirement for systemic opiate analgesia and induce a peripherally vasodilated limb. The length of stay post-operatively, (10 days), appears to be falling as experience accrues and children are being discharged within one week of surgery. The choice of the donor site is important, particularly if the child is likely to undergo further reconstructive procedures, and scarring. Children appear particularly conscious of new scars on exposed sites
280 such as that following a lateral arm flap. Where possible, scarring and functional loss must be minimised and the child and parents prepared for the donor morbidity. In elective cases, preoperative counselling using postoperative photographs and videos of similar patients proved valuable, particularly for children being assessed for thumb reconstruction with a toetransfer. When raising muscle flaps in children, i.e. latissimus dorsi or rectus abdominis, attempts are made to preserve functional muscle at the donor site, and avoid potentiating weakness of the anterior abdominal wall in later life.
Conclusion
Microvascular surgery in children is safe and carries a high success rate. Microsurgery may offer a unique single stage reconstruction with predictable results as reliable, or more reliable, than traditionally accepted procedures. A short postoperative stay and avoidance of repeated surgery makes this technique especially suited to children. The indications for elective microsurgery in children appear different from those usually associated with an adult population, and attention to the functional and aesthetic consequences of the donor site is essential. The vessels in young childrens’ free-tissue transfers are of adequate size for microvascular anastomosis and we have found vessel size largely irrelevant. Similarly in the event of an arterial or venous problem developing post-operatively, early re-exploration is worthwhile. The perioperative maintenance of a warm, pain-free child with a full circulation, is continued into the postoperative period. The control of these variables together with the avoidance of fear, can be closely monitored on a High Dependency Unit, which has proved to be a very valuable resource. Postoperatively, careful splintage and immobilisation of the microvascular transfer is necessary to protect it from the child. Finally, paediatric microsurgery raises special issues of informed consent. The involvement of a clinical counsellor familiar with the evaluation of patients before and after surgery is helpful. In addition the contribution from a specialist paediatric anaesthetist is essential and emphasises the multi-disciplinary approach inherent in surgery of this nature.
British Journal of Plastic Surgery References BanIc, A. and WuBI, K. (1987). Latissimus dorsi free flaps for total repair of extensive lower leg injuries in children. Plastic and Reconstructive Surgery, 19,769.
Black, E. B. (1982). Microsurgery and replantation of tissues in children. Paediatric Annals, 11,918. Chicarilli, Z. N. (1986). Paediatric Microsurgery : Revascularisation and replantation. JournalofPaediatric Surgery, 21,706. Davison, P. M. and Sully, L. (1988). Microvascular surgery to preserve a preterm infant’s ischaemic arm. British Medical Journal, 297,788. Gilbert, A. (1985). Reconstruction of congenital hand defects with microvascular toe-transfers. Hand Clinics, 1,35 1. Harii, K. aad Obmori, K. (1975). Free groin flaps in children. Plastic and Reconstructive Surgery, 55,588.
Iwaya, T., Haril, K. and Yamada, A. (1982). Microvascular free flaps for the treatment of avulsion injuries of the feet in children. Journal of Trauma, 22, 15. Jacobsen, J. H. and Suarez, E. L. (1960). Microsurgery in anastomosis of small vessels. Surgical Forum, 11,243. Jaeger, S. H., Tsal, T. N. and Kleinert, H. E. (1981). Upper extremity replantation in children. Orthopaedic Clinics of North America, 12, 897. Kleinert,
H. E. and Kasdan, M. L. (1965). Anastomosis of digital vessels. Journalof the Kentucky Medical Association, 63,106. Komatsu, S. and Tamal, S. (1968). Successful replantation of a completely cut-off thumb. Plastic and Reconstructive Surgery, 74,
374. Lister, G. (1988). Microsurgical
transfer of the second toe for congenital deficiency of the thumb. Plastic and Reconstructive Surgery, 82,658.
Malt, R. A. and McKbann, C. F. (1964). Replantation of several arms. Journal of the American Medical Association, 189,716. O’Brien, B. McC., FrankIIn, J. D., MorrIson, W. A. and Macleod, A. M. (1980). Replantation and revascularisation surgery in children. The Hand, 12, 12. OkmorI, K., Harii, K., Seklguehi, J. and Torli, S. (1977). The youngest free groin flap yet. British Journal of Plastic Surgery, 30, 273.
Parry, S. W., Toth, B. A. and Elliot, L. F. (1988). Microvascular free tissue transfer in children. Plastic and Reconstructive Surgery, 81, 838. Sekiguchi,
J. and Obmori, K. (1979). Youngest replantation with microsurgical anastomoses. Hand, l&64. YanBeek,A.L., Wavak,P. W.andZook,E.G. (1979). Microvascular surgery in young children. Plastic and Reconstructive Surgery, 63, 457.
The Authors V. S. Lkvarrj, FRCS, Registrar in Plastic Surgery
S. P. Kay, FRCS, FRCS(Plaat), Consultant Plastic Surgeon A. G. Batehelor, FRCS, FRCS(PIa&, Consultant Plastic Surgeon A. Yates, FFARCS, Consultant Anaesthetist Department of Plastic Surgery, St James’s University Hospital, Beckett Street, Leeds LS9 7TF. Requests for reprints to Mr Kay. Paper received 24 October 1990. Accepted 3 December 1990.
,_
Microvascular surgery in children V. S. Devaraj, S. P. Kay, A. G. Batchelor and A. Yates Department of Plastic Surgery, St. James’s University Hospital, Leeds SUMMARY. 43 microvascular procedures were performed in 38 children, (age limit 15 years) over a three year period. The average age was 5.4 years. The majority of the procedures were elective (63%), the remainder urgent or emergency. The overall vascular success rate was 93%, confirming previous reports. Three failures were observed, 2 of these being thumb avulsion iqiuries, the third a free-flap. Two patients underwent re-exploration of the anastomosis with successful outcomes. Vessel size was not a problem and generally exceeded 0.8 mm external diameter. The total time under anaesthetic averaged 5.5 hours, and postoperative recovery included monitoring and pain control on a High Dependency Unit. The average hospital stay was 10 days. The indications for surgery differ from those in adults, management is more complex, and includes the physical and psychosocial care of the child and parents. Despite raising certain anxieties in the past, microvascular surgery in childrenis safe, reliable and carries a high success rate.
Microvascular surgery began experimentally with the work of Jacobson and Suarez (1960). Clinical development quickly followed with reports by Kleinert and Kasdan (1962) of the first thumb revascularization, and by Komatsu and Tamai (1965) of the first thumb replantation. Since then the practice of microsurgery in adults has become well established with success rates exceeding 70%~88%. However despite an early report by Malt and McKhann (1964) who successfully replanted an arm severed at the mid-humeral level, in a 12 year old boy, there remained anxieties over the feasibility of microsurgery in small children. The indications for surgery were inherently different to those encountered in an adult population and there was an assumption that vessel sizes would defy successful anastomosis. Consequently early reports on microsurgery in children were sporadic. Harii and Ohmori (1975) reported free groin flaps in two children aged 4 years, and Ohmori et al. (1977) subsequently reported a successful free groin flap in a baby of three months. He suggested that there was no minimum age for free flap transfer. The donor artery (the common trunk of the superficial circumflex iliac and superficial epigastric arteries), was 0.9 mm and recipient vessel (radial artery), 1.Omm. Corresponding venae comitantes (both donor and recipient vessels) were 2.0 mm. Van Beek et al. (1979) reported eight successful microvascular replantations in children under 6 years with digital injuries. Excellent function, appearance and a maintained potential for growth were observed. The vessels were larger than expected from the child’s size. The same year, Sekiguchi and Ohmori reported on the youngest patient with a successful replantation aged 12 months and 15 days. In 1980, O’Brien et al. reported a series of 18 digital replantations and 13
revascularisations in 27 children with an average age of 6.8 years. The overall digit survival rate was 65% (20 digits), and three factors, the age of the child, the level of the injury and type of injury, influenced the likelihood of success. Thus, only half of the procedures were successful in children less than two years of age, compared with 70% in children over five. This was presumed to be due to the smaller vessel diameter and technically difficult repair. More proximal digital injuries were more likely to survive than distal ones, as were those without a significant element of diffuse crush/avulsion. Those authors emphasised that salvage of any amputated, or devascularised, digit or extremity in a child was worthwhile with favourable outcomes in terms of sensation, growth and function. Further reports supported these observations, (Jaeger et al., 1981, Black, 1982, Chicarilli, 1986). Gilbert (1985) reported 49 cases of second-toe to hand transfer in 38 patients (average age of 24 months), with a 98% success rate. Interestingly he felt that 0.7 mm diameter was the lower limit of safe vessel size for surgery. More recently, Parry et al. (1988) reported 22 elective free-tissue transfers in children aged 2-14 years, with a 96% success rate and only one flap failure. Similarly Lister (1988) has reported 100% survival in 12 toetransfers in children with an average age of two years. Clinical material 38 children had microvascular procedures over a 3year period at St. James’s University Hospital in Leeds. One of two consultant plastic surgeons performed each microvascular procedure. Arteriography was not routinely performed on children preoperatively and clinical examination and exploration were used for elucidating vascular anatomy. However one 276
Microvascular
277
Surgery in Children
13-year-old child with a large juvenile angiofibroma of the nasopharynx underwent preoperative angiography and embolization of the feeding vessels. A two year old child for hand reconstruction following meningococcal septicaemia also underwent angiography because of uncertainty over the extent of vessel obstruction. Toe-transfer for hand reconstruction in congenital deformity was undertaken in children between 10 months and 5 years. In these procedures the transfer was based upon the first cleft vessels of the foot, either the first dorsal metatarsal artery or the plantar system. Recipient vessels in limb microsurgery were axial, using either end-side or end-end anastomoses as appropriate. Suture size varied from 9/O to 10/O and (rarely) 11/O. Heparinised Hartmanns solution was used to irrigate the vessels prior to anastomosis. Both the donor and recipient vessel sizes were recorded (arteries and veins) immediately prior to anastomosis, and following gentle mechanical dilatation if appropriate. Anti-thrombic agents in the form of asprin, dipyridamole, heparin or dextran were not routinely used in this series. Surgery was performed under general anaesthetic supplemented with regional anaesthesia, usually via indwelling catheters to assist with postoperative pain relief. Intraoperative fluid replacement was primarily with colloid, (human albumin solution/Haemacell), or crystalloid. Blood transfusions were largely avoided. Many children had haemoglobin levels as low as 7 g/d1 postoperatively, with however increased or normal intravascular volumes, and thus no adverse sequelae. Postoperatively, depending on anaesthetic preference, the children were either admitted to an Intensive Care Unit (ICU) for elective ventilation, (more common after head and neck procedures), or extubated and transferred to a High Dependency Unit (HDU) for monitoring and pain control, following limb reconstruction. Central venous pressure, heart rate, blood pressure, core-peripheral temperature gradient and urine output were closely monitored as a guide to intravascular volume. Oxygen saturation, respiration rate and pupil reactivity were also monitored as nurse controlled opiate infusions were routine. In older children, Patient Controlled Analgesia systems (opiate infusions) were useful. A bupivacaine infusion through epidural or brachial plexus indwelling catheters assisted pain control. The children were maintained in a critical care environment (ITU or more commonly HDU) until opiates were discontinued and regional anaesthesia catheters removed.
RC?SUltS
Over a 36 month period, (1987-1990), 43 microvascular procedures were performed in 38 children, with an average age of 5.4 years. The youngest was a premature infant born at 28 weeks gestation and weighed under 1 kg. The oldest child was 15 years. Figure 1 illustrates the age distribution, and type of procedure.
:
0
00
n 28
/4.3
: 0
::
.:
n
oo..o Aooer00
1
2
0:
G+--‘*-‘--~ 3
wwt*
4
5
6
7
a
l oo OAAO 9
: 0
10 11 12 13 14 15
b
Age (Years) Fig.
Figure l-Age
1
distribution and type of
procedure.
The microvascular procedures performed in the series are summarised in Table 1, and the indications for surgery in Table 2. The case-mix differed from that associated with an adult population undergoing microvascular surgery, as the congenital hand deformities formed the largest single group. This included a child with constriction band syndrome illustrated in Figure 2. Table 1 children
The
microvascular
procedures
Free tlap Toe-transfer Replantation Revascularisation
Table 2
The indications
performed
in
22 14 4 3
for surgery
Congenital hand deformity Road traffic accident Bum Tumour Replant/Revascularisation Other
12 7 5 4 7 3
27 of the procedures were elective (63x), while 16 were either emergency or urgent, (37%). The donor sites used in the series are recorded in Table 3. A latissimus dorsi flap being raised in a 5-month-old child is shown in Figure 3. Both the donor and recipient vessel sizes were recorded (arteries and veins) immediately prior to anastomosis and ranged between 0.4-3.0 mm (external diameter) with an internal diameter exceeding 0.3 mm. The mean time under anaesthesia was 5.5 hours (range 2.5-9.5). The operative time was generally one hour shorter (4.5 hours). There were no unsuccessful procedures in those children undergoing elective microvascular surgery. Figure 4 illustrates a thumb reconstruction using a second toe-transfer, in the immediate postoperative period. Overall, 40 microvascular procedures were
278
British Journal of Plastic Surgery Table 4
The outcome of microvascular
surgery
No. of cases
Success
Failure
Elective Free-flaps Toe-transfers
13 14
13 14
0 0
Emergency Free-flaps Replantations Revasc.
9 4 3
8 2 3
1 2 0
Fig. 2 Figure 2-Congenital constriction band syndrome, in a 5-year-old. She underwent bilateral second toe-transfers.
Table 3
The donor sites used in the series Latissimus dorsi Lateral arm Scapular Rectus abdominis Fibular Second-toe Wrap-around toe flap
10 I 2 2 1 12 2 Fig. 4 Figure 4-A thumb reconstruction, using a second toe-transfer in a 2-year-old child with symbrachydactyly.
Fig. 3 Figure %A child.
latissimus dorsi flap being raised in a 5-month-old
successful (93x), and 3 failed (70/,). The outcome of the microvascular procedures performed is summarised in Table 4. The 3 failures (7”/,), included two replantations for crush/avulsion injuries of the distal thumb, both boys aged 6 and 11 years. Both children subsequently underwent successful thumb reconstructions using
wrap-around toe flaps, one as a delayed primary, the other as a secondary procedure. One latissimus dorsi free-flap failed in a 5-month-old baby due to irreversible venous thrombosis. This child had multiple congenital anomalies and was referred three weeks following primary surgery for club foot. The leg was severely injured and septic. Despite vein grafting to the popliteal fossa, we were unable to escape the zone of injury. Heparin injected directly into the flap, coupled with a systemic prostacyclin infusion failed to reverse the venous thrombosis in this infant, and reexploration was not helpful. Two other flaps in the series were re-explored, (reexploration rate 4.6%), and salvaged. One was a toetransfer in a 4-year-old which developed venous congestion on the night of surgery. At re-exploration, division of a tight skin bridge overlying the microvascular pedicle improved flap perfusion immediately. The other was an 8 year old undergoing a lateral arm free-flap which required revision of both arterial and venous anastomoses during the primary procedure as the vessels developed platelet thrombi. There was one minor complication, a small haematoma which developed in a lateral arm flap, 4 days post-operatively. The
Microvascular Surgery in Children
279
flap viability was not compromised and the haematoma removed without formal re-exploration. The overall mean post-operative stay was 9.8 days per microvascular transfer. This figure excluded two longer stays due to co-existant limb fractures, and unrelated to the microsurgery.
Discussion Microvascular surgery in children in our series carries a high overall success rate, (93%). There were no failures in the group of children undergoing elective microsurgery. In addition, there is a low complication rate (2x), confirming previous reports. The youngest patient to undergo a microvascular procedure, a baby born at 28 weeks gestation, represents the youngest patient on record. Davison and Sully (1988) previously advocated early microvascular surgery for ischaemia in the limbs of newborns in their report of a baby with a gestational age of 30 weeks. The baby in our series had a complete avulsion of the right common iliac artery during the removal of an aortic valvotomy catheter. FolIowing unsuccessful attempts at reanastomosis to the aorta including veingrafting, a femoro-femoral cross-over vein graft was performed. Initially this vein graft also became occluded but a streptokinase infusion improved limb vascularity, and the graft remained patent, with limb pulses demonstrably absent during digital occlusion of the extra-anatomic vein graft. The two other revascularisations were injuries to the brachial artery, sustained during cardiac catheterisation procedures in infants aged 3 weeks and 12 months. The younger child required a vein graft. The major indication for emergency microsurgery was trauma from road traffic accidents. Free tissue transfer provided a unique solution in crush or degloving injuries of the lower extremities, particularly feet, seen in 6 children, (Fig. 5). In this context, the latissimus dorsi flap was most commonly used, and anastomosed to the anterior tibia1 artery and either a venae commitans or superficial vein. Other authors have described similar experiences in children, (Iwaya et al., 1982, Banic and Wulff 1987). Both early and late reconstructive problems arose from bum injuries in 5 children. Late problems included adduction contracture in the first web space requiring release and resurfacing using the lateral arm free-flap. One three year old child sustained an extensive hand burn from an electric bar fire. This was debrided the day following injury and skin cover obtained with a free latissimus dorsi flap. He subsequently underwent a second toe-transfer. In two patients severe post-burn contractures of the neck were reconstructed using scapular flaps, one of which was tissue expanded prior to transfer. Good quality skin, colour match and an easily closed donor site were obtained. Two of the four tumours in the series, were rhabdomyosarcomas in children aged 8 and 13 years, one arising in the infra-temporal fossa, the other on the foot. The tumours were excised and the area resurfaced using a latissimus dorsi or a lateral arm flap
Fig. 5 Figure 5-A latissimus dorsi free flap used to resurface a severely injured foot and exposed ankle joint.
respectively. Similarly, the volume defects resulting from excision of a Ewing’s sarcoma in a maxillary antrum and a juvenile angiofibroma in a nasopharynx were filled using rectus abdominis free-flaps, in two children also aged 8 and 13 years. Two replantations of the four in the series failed. Both were thumb avulsion injuries that suffered postoperative venous occlusion. The two successful replantations included a 12 year old with a mid-forearm avulsion amputation. This patient also underwent a lateral arm free-flap some three weeks following replantation to provide additional skin cover to the hand. The smallest vessels anastomosed in this series were superficial (dorsal) veins with an external diameter of 0.4 mm in a child aged 2 years, who sustained an amputation through the proximal phalanx of an index finger, which was successfully replanted. Vessel size per se was not a limiting factor in this series, and the majority of vessels exceeded 0.8 mm external diameter, in keeping with previous reports. Similarly, as reported by Parry et aZ.-(1988), intraoperative vessel spasm was not a problem. The vessel lumen was usually pristine although this was not true of the failed free flap, where previous surgical trauma and sepsis had resulted in a friable and oedematous intimal lining. Postoperative ventilation overnight on an ICU ox extubation and transfer to a HDU allowed the main factors influencing vasospasm to be controlled i.e. cooling, intravascular volume, fear and pain. Infusion of bupivacaine, (0.1-0.25%), through a cannula in the sheath around the brachial plexus in upper limb microsurgery appeared to reduce the requirement for systemic opiate analgesia and induce a peripherally vasodilated limb. The length of stay post-operatively, (10 days), appears to be falling as experience accrues and children are being discharged within one week of surgery. The choice of the donor site is important, particularly if the child is likely to undergo further reconstructive procedures, and scarring. Children appear particularly conscious of new scars on exposed sites
280 such as that following a lateral arm flap. Where possible, scarring and functional loss must be minimised and the child and parents prepared for the donor morbidity. In elective cases, preoperative counselling using postoperative photographs and videos of similar patients proved valuable, particularly for children being assessed for thumb reconstruction with a toetransfer. When raising muscle flaps in children, i.e. latissimus dorsi or rectus abdominis, attempts are made to preserve functional muscle at the donor site, and avoid potentiating weakness of the anterior abdominal wall in later life.
Conclusion
Microvascular surgery in children is safe and carries a high success rate. Microsurgery may offer a unique single stage reconstruction with predictable results as reliable, or more reliable, than traditionally accepted procedures. A short postoperative stay and avoidance of repeated surgery makes this technique especially suited to children. The indications for elective microsurgery in children appear different from those usually associated with an adult population, and attention to the functional and aesthetic consequences of the donor site is essential. The vessels in young childrens’ free-tissue transfers are of adequate size for microvascular anastomosis and we have found vessel size largely irrelevant. Similarly in the event of an arterial or venous problem developing post-operatively, early re-exploration is worthwhile. The perioperative maintenance of a warm, pain-free child with a full circulation, is continued into the postoperative period. The control of these variables together with the avoidance of fear, can be closely monitored on a High Dependency Unit, which has proved to be a very valuable resource. Postoperatively, careful splintage and immobilisation of the microvascular transfer is necessary to protect it from the child. Finally, paediatric microsurgery raises special issues of informed consent. The involvement of a clinical counsellor familiar with the evaluation of patients before and after surgery is helpful. In addition the contribution from a specialist paediatric anaesthetist is essential and emphasises the multi-disciplinary approach inherent in surgery of this nature.
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The Authors V. S. Lkvarrj, FRCS, Registrar in Plastic Surgery
S. P. Kay, FRCS, FRCS(Plaat), Consultant Plastic Surgeon A. G. Batehelor, FRCS, FRCS(PIa&, Consultant Plastic Surgeon A. Yates, FFARCS, Consultant Anaesthetist Department of Plastic Surgery, St James’s University Hospital, Beckett Street, Leeds LS9 7TF. Requests for reprints to Mr Kay. Paper received 24 October 1990. Accepted 3 December 1990.