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Experiences in surgical repair of a totally avulsed scalp
J. Cranio-Max.-Fac.Surg. 19 (199i) J. Cranio-Max.-Fac. Surg. 19 (1991) 185-190 © Georg Thieme Verlag Stuttgart • New York
Experiences in Surgical Repair of a Totally Avulsed Scalp Klaus Bitter, Hans-Peter Howaldt Dept. Maxillo-FacialSurgery (Head: Prof. K. Bitter, M.D., D.M.D.), University Hospital, Frankfurt, Germany Submitted 12. 4. 1990, accepted 2. 3. 1991
185
Summary A case of total scalp avulsion is described in surgical detail. The neurovascular bundles remained nearly untouched on the surface of the galea aponeurotica. Only one frontal branch of the left temporal artery was found to serve as a nutrient vessel for the whole scalp. Three veins around the scalp circumference supplied the venous drainage. The right-dorsal part of the scalp underwent necrosis, obviously because of internal disruption on the capillary level. This area had to be skingrafted secondarily. Mechanical aspects in respect of the neuro-vascular situation are discussed theoretically and some advice on the surgical approach is derived from our experience. Key words
Introduction Partial or total scalp avulsion is an extremely rare accident in industrial countries. Effective safety guards, especially on rotating machinery as well as a requirement for machine workers to cover long hair has nearly eliminated the risk of a hair tuft being caught by a rotating wheel. In developing countries, where old unprotected machinery is still in widespread use and where hairstyles, in part for religious reasons, create more of a risk in view of the modern mechanical sources of danger, scalping injury is far more frequent (Feierabend and Bindra, 1985). The same discrepancy is to be noticed in the reports on treatment of this severe laceration. They reflect the whole history of surgical methods applied to reestablish the covering of the bony skull. Our surgical great-grandfathers had to decide whether to throw the scalp away or re&ape it in terms of a free graft. Despite lack of any valuable case reports, one can assume that total necrosis occurred, due at least to the consequent uncontrollable wound infection. For these reasons, Feierabend and Bindra (1985) from India did not dare to replace the scalp but took care of the wound bed to optimise the conditions for sound granulation tissue which they covered with split skin grafts. Regarding the difficulties and even the possibility of split skin grafting the skull, Caldwell (1976) reemphasized the anatomical layers of the scalp, these being (1) cutis, (2) subcutis, (3) galea aponeurotica, (4) areolar tissue and (5) the periosteum. The areolar tissue seems to be the most sensitive to mechanical insults. In some cases, however, the periosteum can also be torn off, leaving behind bare bone from which granulation tissue sprouts only very slowly. Caldwell (1976) therefore recommends staged grafting. Nummi and Arppe (1971) split the scalp itself in two cases, aiming at maintenance of hair growth. Their method is considered to be a full thickness skin graft. They observed partial skin loss in areas where the periosteum was torn off together with the scalp and the replanted scalp had to be placed on bare bone. Hair was reduced to sparse growth. They mention the very important factor of keeping the scalp dry and cool until it reaches the operating room. In this context Lu's (1969) report on a successful replacement of an occipital scalp flap is very interesting. The author did not believe the scalp would take - but it took completely. Reflecting on
Total scalp avulsion - Micro-surgery - Scalp vessel anatomy under surgical aspects
the possibly significant conditions for this praiseworthy success he mentioned four crucial points. (1) the scalp must not be damaged mechanically in its internal structure (2) do not use any surgical disinfection (3) do not rinse the scalp in "physiological" saline (4) do not use any forceps or similar instruments during replacement of the scalp. He only rinsed the periosteum with plasma. This statement throws more than a spotlight on the biological conditions of an avulsed scalp. Overall, the success rate of scalp replantation remained unsatisfactory. Even split skin grafting to the skull pleased neither the surgeon nor the patient. Following the introduction of microsurgical techniques for reanastomosing small blood vessels, Caldwell (1976) claimed a totally logical scalp reconstruction by re-establishing the blood flow through the avulsed tissue. He felt his own success in one case might be an unique one, depending on several unrecognizable biological circumstances. Consequently, Miller et al. (1976) published the first successful microsurgical replantation of a totally avulsed scalp. They reanastomosed both superficial temporal arteries and one orbital vein. Postoperatively, a partial necrosis in the occipital region was observed. From these different experiences several questions arise: (1) how many anastomoses are necessary to guarantee complete blood flow, (2) does partial necrosis depend only on lack of blood flow or are there other reasons such as internal tissue laceration, pressure by the wound dressing or the head weight compromise the occipital region? The detailed description of the following case may help to answer these questions.
Case Report In the late afternoon of 26.6. 86, a young 15-year-old girl was riding on a moving vehicle and had to pass a tree. To clear the branches she had to bow her head and her long
186
J. Cranio-Max.-Fac. Surg, 19 (1991)
K. Bitter, H.-P. Howaldt
Fig. 1 a
Fig. 1 c Fig. 1 a - e
Fig. 1 b tery.
Arrow indicates a main trunk of the superficial temporal at-
Fig. 1 d
Fig. 1 e
Fresh total scalp avulsion and missing scalp parts parietal and occipital.
hair was caught by a high speed rotating cardan shaft. The complete scalp including the forehead, the upper half of both eyelids and the hairless neck skin were torn off and coiled round the still rotating shaft. The emergency call was responded to immediately. The emergency unit commenced shock therapy and carefully freed the scalp from the shaft. They put it into a dry plastic bag which itself was placed in a second bag together with ice. Within half an hour the girl was transferred by helicopter to the hospital. Her general condition was good. On account of the severe blood loss she had to be transfused a total amount of 4,500 ml of whole blood. One and a half hours after the accident she was in the operating room ready for surgery. The open skull wound and the surrounding sound tissue was cautiously rinsed and cleansed avoiding further bleeding as far as possible. Mso the scalp, after cutting the hair tuft off, was only rinsed with Ringer-Lactate solution. No surgical disinfectant was used. The girl's head was a terrible
sight. No wonder there was considerable apprehension among the surgeons, anaesthesists and the nurses, all appreciating the devastating consequences for the girl's whole life, if the replantation should fail. The avulsion line on the skin surface was as follows: (Figs. 1 and 2). Just below to the glabella on the nasal dorsum and then running along the upper border of the upper tarsal plate on both sides. Further, all the way back to the low hairless neck region. On the right side it ran across the retroauricular sulcus into the deep surface of the auricle. Part of the auricular cartilage was denuded. On the left side the wound edge was located more dorsally in the mastoid region. Regarding the tear-avulsion level, the situation was as follows: (Figs. 1 and 3). Overall the galea remained on the skull untouched. Only on top of the skull was a 4 x 5 cm area showing denuded bone. The neuro-vascular bundles as far as the galea, were all in place (Figs. I a, b and 2). This finding depressed the surgeon, because it excluded the possibility of microsurgical vessel reanastomosis. A second
Surgical Repair of a Totally Avulsed Scalp
J. Cranio-Max.-Fac. Surg. 19 (1991)
187
\ Site of
Site of
'
lost parts
~f
asto.
of
rial sto;is
'S~
,
v.
anastomosis Site of v. anastomosis
Fig. 2
Schematic drawing of the descalped skull.
Fig.4
Replanted scalp; see also Fig. 1 d
Fig.5
Fig.3
Schematic drawing of the avulsed scalp.
Granulation tissue in the defect.
Fig.6
Skin grafting of the defect.
and 1 e.
look, however, revealed the frontal branch of the temporal artery disrupted half way to the forehead region. The diameter of the contracted vessel was 0.4ram. After stretching the lumen with a special Acland forceps, the diameter increase to 0.Smm. Under the microscope one could clearly recognize that no stripping of the intima or media had occurred. The vessel looked as if it had been cut. Fresh continous bleeding confirmed the viability of the artery, which could be clamped with an Acland microclip Nr. A3. The scalp itself was defective (Figs. i e, d and 3). From the right parietal and occipital region large parts were missing. The tissue remaining appeared to be of sound quality, at least macroscopically. Veins or arteries were not to be seen during the first check. As a consequence of the vessel situation on the skull, in the left fronto-parietal part of the scalp
the distal branch of the temporal artery had to be sought for. After an hour of careful and at times desperate search, the vessel was found retracted under the inner surface of the scalp. Microscopically it was judged to be unstripped like its proximal component. The scalp was then draped onto the skull and secured with several single sutures in the correct position. The left wound edge was elevated to perform the micro-anastomosis. Immediately after release of the Acland-A3-aproximator the whole scalp showed an arterial flush. Even the right part, only connected by two narrow bridges to the left larger part, unexpectedly began to bleed from the wound edges. The veins could not be recognized beforehand. But after reestablishing the arterial blood flow bursting little sausages bulged 'from the scalp edges and undersurface. It was relatively easy to find three corresponding veins on the skull
188
J. Cranio-Max.-Fac. 8urg. 19 (1991)
K. Bitter, H.-P. Howaldt Fig. 8 a
Fig.7
Area behind the ear,
and to anastomose them. The whole scalp looked marvellous and only had to be sutured in the usual way (Fig. 4). The missing parts were left open for split skin grafting at a later date. The occipital region was padded with surgical cotton wool and the whole skull covered with the usual dressing. Under systemic antibiotic therapy the scalp looked more or less normal for two days. On the third day the right part, nourished only through two tissues bridges, showed signs of necrobiosis. No signs of venous insufficiency could be noted. Under observation, the necrobiosis turned to definite necrosis. After a week this part was removed easily without any anaesthetic, revealing sound granulation tissue on the underlying skull surface (Fig. 5). On 17.7.86 split skin from both buttocks and the lower part of the back were grafted onto the granulating areas (Fig. 6). During this session, the denuded parietal bone was drilled to the spongiosa to encourage formation of granulation tissue even in this part. On 15.8.86 this area could be grafted too. The transplanted skin took primarily, except for a smal area behind the right auricle (Fig. 7). The upper helix was attached to the skull. On 25.8.88 the scar from the region caudal to the auricle was excised and grafted onto the failed area to create a complete retroauricular sulcus. Fig. 8 portrays the girl a year later with a hair tuft comprising 80 % of her own hair and a fixed bald patch combed to the right side. Some minor scar revisions may be necessary. Regarding the scars at the skin donor site, staged excision over several years is intended. Discussion and Conclusions Faced with a scalp avulsion it is most important to analyse the arterial and venous situation. Fig. 9 outlines the layers of the skull capsule. The arteries and veins run within the subcutaneous fat just on the surface of the galea aponeurotica. Contrary to CaldweU (1976), we think the subcutane-
Fig.8b
Fig.8a-b
Final result a year Later.
ous layer is mechanically least resistant. Experimental data, however, do not exist. If the scalp is torn off along this layer, the question arises, whether the blood vessels are included or not. Overall, arteries and even veins are tougher than subcutaneous connective tissue. Supposing that the direction of avulsion is perpendicular to the skull, laterally the force is tangential whereas over the vault of the head it acts vertically. Anywhere between these extremes an equilibration of vessel resistance and shearing force occurs. For example: when one tries to detach a stamp from an envelope, one has to do it tangentially. Any vertical traction would immediately tear the stamp together with the envelope. For these reasons one does not expect to find the vessel injuries at the level of skin disruption in scalp avulsion. They have rather to be sought further distally to the central part of the skull wound.
Surgical Repair of a Totally Avulsed Scalp
J. Cranio-Max.-Fac.Surg. 19 (1991)
Tear-Off-Direction
+
~
V
Cuffs ,/<-G~, ~ " - _ \ ~ / Subcutis w - = - f ~ l J ~
e
s
~
~
s~
•
,
e,
-
l
, ~ ~ ~f-Bone t..
Galea
--Periost
Fig.9 Schematical drawing of the skull layers.
In our case only one artery was disrupted so far proximally that it could serve for micro-anastomosis. In cases of minor central scalp avulsion it seems possible to find no vessel easily available for resupplying the scalp flap (Nurnmi and Arppe, 1971). On the other hand, regarding the arterial blood supply, the biological nature of the scalp is favourable. Only one artery completely nourishes the large skin flap. This observation confirms Miller's et al. experience (1976). It depends on an extensive system of anastomoses between the main arterial trunks. Nevertheless, two or more microsurgical repairs seem to be more valid in view of the sensitive patency rate. This is especially important in older patients with sclerotic and more fragile vessels. Our patient was young with vessels of optimal quality, so that no intimal stripping occurred and the perfusion capability was maximal. Certainly there is a correlation between the degree of sclerosis and the success rate under any circumstances. We do not, however, have any method for predicting success. Replantation should be tried therefore in every case, with regard to the alternative. The veins present less difficulty, though they could not be found before reestablishing the blood flow. Because of their thin walls, they collapse totally. When the internal pressure rises, however, they fill and the corresponding parts can easily be found because of exact localisation reference points. Depending on the low pressure as many veins as possible should be reanastomosed. Another important point is how the vessels are torn. Remember, we are not dealing with a cutting injury. So it may be possible, that the vessel wall layers are stripped off. The outer adventitia may look normal but the internal lining has broken down (intima or even media). Microscopical examination and the test for bleeding is strictly necessary. If the vessel wall layers are disrupted, the stumps have to be cut strictly back until normal conditions are reached. This usually creates a minor or wider gap between the vessel ends. These gaps have to be bridged with the help of vein grafts from the forearm or anywhere else (Miller et al., 1976). In our case the vessels were disrupted as if cut, probably dependant on the youth of the patient. In the elderly the elasticity of the media diminishes and forces the surgeon to look carefully for the stripping phenomenon.
What about the necrosis of the right lateral scalp part? Full arterial blood supply was resumed after release of the aproximator. Eventually a moist necrobiosis and later necrosis occurred without any sign of venous congestion. So it could not be blamed on the patency of the venous anastomoses. The phenomenon was described clinically as a "delayed non-reflow-phenomenon". Possible reasons are: (1) too much pressure from the surgical dressing or (2) internal tissue disruption at the capillary level.
189
Regarding (1), Acland (1981) warns against faulty wound dressing technique in microsurgical free flap transfer. Every additional turn of a bandage puts an increased amount of pressure on the tissue surface. Even if every turn is very loose, the sum of the pressures can be high enough to exceed the capillary blood pressure. From this it seems reasonable to omit a dressing and leave the wound open. In the case of neck scalp avulsion one has to take the weight of the head from the replanted scalp. As Steinau (1989) recommended, a head gear is suitable for this purpose. In our patient, however, the necrosis occurred laterally in the neck region, where no external pressure was exerted. Rather, internal tissue arrangement was probably severely disturbed because the scalp was twisted round the cardan shaft very tightly and rotated there for a while. Obviously the two large missing parts were punched out by this occurrence and crushed completely, so that they could not be conserved by the emergency unit. No wonder then the surrounding parts of the scalp were severely traumatized. Lu's (1969) statement gives support to this presumption, in that he insists on avoidance of any mechanical insult to the scalp, otherwise the reanimation of the tissue would fail. The operating team, faced with such a severe but rare laceration, may be affected by apprehension reflecting more or less unconciously the future fate of the patient. The rarity of a total scalp avulsion may lead to a lack of a proper treatment-plan by the surgeon. Two of Millard's principles of plastic surgery (1986) are therefore of great importance: (1) diagnosis before treatment and (2) put normal to normal. A special surgical schedule might be helpful to cope with the problem. 1. Scrutinize the vessel situation on the skull, bearing in mind the normal anatomy of the main neuro-vascular trunks: Supraorbital, temporal and occipital, on both sides. 2. Do not worry about the veins. 3. When the arteries are identified and one or more seem suitable for micro-anastomosis, search carefully and patiently in the scalp to identify the corresponding distal portion. With the help of localisation reference you will succeed in discovering them. 4. Deal with the veins only after release of the arterial blood flow. It helps identify the vein stumps. It is much easier to find corresponding veins than arteries. 5. Do not worry about the time you need for the procedure; the scalp tissue is very tolerant of oxygen deprivation. 6. Save the cut hair tuft for a temporary wig. Finally a further aspect of revisional surgery shall be mentioned. It is possible to enlarge the hair bearing parts of the scalp with the help of tissue expanders. At present our patient is not willing to undergo such a procedure. But time will possibly change her mind. The split skin donor site was placed dorsally to get it out of sight for the girl and to be able to cover it with a swim suit. The scarred areas are going to be removed in stages over the following couple of years. So far the girl is happy and has a boyfriend, like others.
References Acland, R.: Pers. comm. 1981 Caldwell, E.H.: Complete scalp avulsion. Arch. Surg. 111 (1976) 159
190
J. Cranio-Max.-Fac. Surg. 19 (1991)
Feierabend, T. C., IL N. Bindra: Injuries causing major loss of scalp. Plast. Reconstr. Surg. 76 (1985) 189 Lu, M.'. Successful replacement of avulsed scalp. Plast. Reconstr. Surg. 43 (1969) 231 Millard, D.R. jr.: Principlization of plastic surgery. Little, Brown. Boston/Toronto (1986), 149 and 160 Miller, E., D. H. Graeme, E.J. Austee, J. A. Snell: Successful replantation of an avulsed scalp by microvascular anastomoses. Plast. Reconstr. Surg. 58 (1976) 133 Nummi, P., A. Arppe: Replacement of the avulsed scalp. Scand. J. Plast. Reconstr. Surg. 5 (1971) 67 Steinau: Pets. comm. (1989)
K. Bitter, H.-P. Howaldt: Surgical Repair of a Totally Avulsed Scalp. Prof. Dr. K. Bitter, M.D., D.M.D. Johann-Wolfgang-Goethe-Universitiit Abt. Kiefer- und Gesichtschirurgie Theodor-Stern-Kai 7 W-6000 Frankfurt 70 Germany
Experiences in Surgical Repair of a Totally Avulsed Scalp Klaus Bitter, Hans-Peter Howaldt Dept. Maxillo-FacialSurgery (Head: Prof. K. Bitter, M.D., D.M.D.), University Hospital, Frankfurt, Germany Submitted 12. 4. 1990, accepted 2. 3. 1991
185
Summary A case of total scalp avulsion is described in surgical detail. The neurovascular bundles remained nearly untouched on the surface of the galea aponeurotica. Only one frontal branch of the left temporal artery was found to serve as a nutrient vessel for the whole scalp. Three veins around the scalp circumference supplied the venous drainage. The right-dorsal part of the scalp underwent necrosis, obviously because of internal disruption on the capillary level. This area had to be skingrafted secondarily. Mechanical aspects in respect of the neuro-vascular situation are discussed theoretically and some advice on the surgical approach is derived from our experience. Key words
Introduction Partial or total scalp avulsion is an extremely rare accident in industrial countries. Effective safety guards, especially on rotating machinery as well as a requirement for machine workers to cover long hair has nearly eliminated the risk of a hair tuft being caught by a rotating wheel. In developing countries, where old unprotected machinery is still in widespread use and where hairstyles, in part for religious reasons, create more of a risk in view of the modern mechanical sources of danger, scalping injury is far more frequent (Feierabend and Bindra, 1985). The same discrepancy is to be noticed in the reports on treatment of this severe laceration. They reflect the whole history of surgical methods applied to reestablish the covering of the bony skull. Our surgical great-grandfathers had to decide whether to throw the scalp away or re&ape it in terms of a free graft. Despite lack of any valuable case reports, one can assume that total necrosis occurred, due at least to the consequent uncontrollable wound infection. For these reasons, Feierabend and Bindra (1985) from India did not dare to replace the scalp but took care of the wound bed to optimise the conditions for sound granulation tissue which they covered with split skin grafts. Regarding the difficulties and even the possibility of split skin grafting the skull, Caldwell (1976) reemphasized the anatomical layers of the scalp, these being (1) cutis, (2) subcutis, (3) galea aponeurotica, (4) areolar tissue and (5) the periosteum. The areolar tissue seems to be the most sensitive to mechanical insults. In some cases, however, the periosteum can also be torn off, leaving behind bare bone from which granulation tissue sprouts only very slowly. Caldwell (1976) therefore recommends staged grafting. Nummi and Arppe (1971) split the scalp itself in two cases, aiming at maintenance of hair growth. Their method is considered to be a full thickness skin graft. They observed partial skin loss in areas where the periosteum was torn off together with the scalp and the replanted scalp had to be placed on bare bone. Hair was reduced to sparse growth. They mention the very important factor of keeping the scalp dry and cool until it reaches the operating room. In this context Lu's (1969) report on a successful replacement of an occipital scalp flap is very interesting. The author did not believe the scalp would take - but it took completely. Reflecting on
Total scalp avulsion - Micro-surgery - Scalp vessel anatomy under surgical aspects
the possibly significant conditions for this praiseworthy success he mentioned four crucial points. (1) the scalp must not be damaged mechanically in its internal structure (2) do not use any surgical disinfection (3) do not rinse the scalp in "physiological" saline (4) do not use any forceps or similar instruments during replacement of the scalp. He only rinsed the periosteum with plasma. This statement throws more than a spotlight on the biological conditions of an avulsed scalp. Overall, the success rate of scalp replantation remained unsatisfactory. Even split skin grafting to the skull pleased neither the surgeon nor the patient. Following the introduction of microsurgical techniques for reanastomosing small blood vessels, Caldwell (1976) claimed a totally logical scalp reconstruction by re-establishing the blood flow through the avulsed tissue. He felt his own success in one case might be an unique one, depending on several unrecognizable biological circumstances. Consequently, Miller et al. (1976) published the first successful microsurgical replantation of a totally avulsed scalp. They reanastomosed both superficial temporal arteries and one orbital vein. Postoperatively, a partial necrosis in the occipital region was observed. From these different experiences several questions arise: (1) how many anastomoses are necessary to guarantee complete blood flow, (2) does partial necrosis depend only on lack of blood flow or are there other reasons such as internal tissue laceration, pressure by the wound dressing or the head weight compromise the occipital region? The detailed description of the following case may help to answer these questions.
Case Report In the late afternoon of 26.6. 86, a young 15-year-old girl was riding on a moving vehicle and had to pass a tree. To clear the branches she had to bow her head and her long
186
J. Cranio-Max.-Fac. Surg, 19 (1991)
K. Bitter, H.-P. Howaldt
Fig. 1 a
Fig. 1 c Fig. 1 a - e
Fig. 1 b tery.
Arrow indicates a main trunk of the superficial temporal at-
Fig. 1 d
Fig. 1 e
Fresh total scalp avulsion and missing scalp parts parietal and occipital.
hair was caught by a high speed rotating cardan shaft. The complete scalp including the forehead, the upper half of both eyelids and the hairless neck skin were torn off and coiled round the still rotating shaft. The emergency call was responded to immediately. The emergency unit commenced shock therapy and carefully freed the scalp from the shaft. They put it into a dry plastic bag which itself was placed in a second bag together with ice. Within half an hour the girl was transferred by helicopter to the hospital. Her general condition was good. On account of the severe blood loss she had to be transfused a total amount of 4,500 ml of whole blood. One and a half hours after the accident she was in the operating room ready for surgery. The open skull wound and the surrounding sound tissue was cautiously rinsed and cleansed avoiding further bleeding as far as possible. Mso the scalp, after cutting the hair tuft off, was only rinsed with Ringer-Lactate solution. No surgical disinfectant was used. The girl's head was a terrible
sight. No wonder there was considerable apprehension among the surgeons, anaesthesists and the nurses, all appreciating the devastating consequences for the girl's whole life, if the replantation should fail. The avulsion line on the skin surface was as follows: (Figs. 1 and 2). Just below to the glabella on the nasal dorsum and then running along the upper border of the upper tarsal plate on both sides. Further, all the way back to the low hairless neck region. On the right side it ran across the retroauricular sulcus into the deep surface of the auricle. Part of the auricular cartilage was denuded. On the left side the wound edge was located more dorsally in the mastoid region. Regarding the tear-avulsion level, the situation was as follows: (Figs. 1 and 3). Overall the galea remained on the skull untouched. Only on top of the skull was a 4 x 5 cm area showing denuded bone. The neuro-vascular bundles as far as the galea, were all in place (Figs. I a, b and 2). This finding depressed the surgeon, because it excluded the possibility of microsurgical vessel reanastomosis. A second
Surgical Repair of a Totally Avulsed Scalp
J. Cranio-Max.-Fac. Surg. 19 (1991)
187
\ Site of
Site of
'
lost parts
~f
asto.
of
rial sto;is
'S~
,
v.
anastomosis Site of v. anastomosis
Fig. 2
Schematic drawing of the descalped skull.
Fig.4
Replanted scalp; see also Fig. 1 d
Fig.5
Fig.3
Schematic drawing of the avulsed scalp.
Granulation tissue in the defect.
Fig.6
Skin grafting of the defect.
and 1 e.
look, however, revealed the frontal branch of the temporal artery disrupted half way to the forehead region. The diameter of the contracted vessel was 0.4ram. After stretching the lumen with a special Acland forceps, the diameter increase to 0.Smm. Under the microscope one could clearly recognize that no stripping of the intima or media had occurred. The vessel looked as if it had been cut. Fresh continous bleeding confirmed the viability of the artery, which could be clamped with an Acland microclip Nr. A3. The scalp itself was defective (Figs. i e, d and 3). From the right parietal and occipital region large parts were missing. The tissue remaining appeared to be of sound quality, at least macroscopically. Veins or arteries were not to be seen during the first check. As a consequence of the vessel situation on the skull, in the left fronto-parietal part of the scalp
the distal branch of the temporal artery had to be sought for. After an hour of careful and at times desperate search, the vessel was found retracted under the inner surface of the scalp. Microscopically it was judged to be unstripped like its proximal component. The scalp was then draped onto the skull and secured with several single sutures in the correct position. The left wound edge was elevated to perform the micro-anastomosis. Immediately after release of the Acland-A3-aproximator the whole scalp showed an arterial flush. Even the right part, only connected by two narrow bridges to the left larger part, unexpectedly began to bleed from the wound edges. The veins could not be recognized beforehand. But after reestablishing the arterial blood flow bursting little sausages bulged 'from the scalp edges and undersurface. It was relatively easy to find three corresponding veins on the skull
188
J. Cranio-Max.-Fac. 8urg. 19 (1991)
K. Bitter, H.-P. Howaldt Fig. 8 a
Fig.7
Area behind the ear,
and to anastomose them. The whole scalp looked marvellous and only had to be sutured in the usual way (Fig. 4). The missing parts were left open for split skin grafting at a later date. The occipital region was padded with surgical cotton wool and the whole skull covered with the usual dressing. Under systemic antibiotic therapy the scalp looked more or less normal for two days. On the third day the right part, nourished only through two tissues bridges, showed signs of necrobiosis. No signs of venous insufficiency could be noted. Under observation, the necrobiosis turned to definite necrosis. After a week this part was removed easily without any anaesthetic, revealing sound granulation tissue on the underlying skull surface (Fig. 5). On 17.7.86 split skin from both buttocks and the lower part of the back were grafted onto the granulating areas (Fig. 6). During this session, the denuded parietal bone was drilled to the spongiosa to encourage formation of granulation tissue even in this part. On 15.8.86 this area could be grafted too. The transplanted skin took primarily, except for a smal area behind the right auricle (Fig. 7). The upper helix was attached to the skull. On 25.8.88 the scar from the region caudal to the auricle was excised and grafted onto the failed area to create a complete retroauricular sulcus. Fig. 8 portrays the girl a year later with a hair tuft comprising 80 % of her own hair and a fixed bald patch combed to the right side. Some minor scar revisions may be necessary. Regarding the scars at the skin donor site, staged excision over several years is intended. Discussion and Conclusions Faced with a scalp avulsion it is most important to analyse the arterial and venous situation. Fig. 9 outlines the layers of the skull capsule. The arteries and veins run within the subcutaneous fat just on the surface of the galea aponeurotica. Contrary to CaldweU (1976), we think the subcutane-
Fig.8b
Fig.8a-b
Final result a year Later.
ous layer is mechanically least resistant. Experimental data, however, do not exist. If the scalp is torn off along this layer, the question arises, whether the blood vessels are included or not. Overall, arteries and even veins are tougher than subcutaneous connective tissue. Supposing that the direction of avulsion is perpendicular to the skull, laterally the force is tangential whereas over the vault of the head it acts vertically. Anywhere between these extremes an equilibration of vessel resistance and shearing force occurs. For example: when one tries to detach a stamp from an envelope, one has to do it tangentially. Any vertical traction would immediately tear the stamp together with the envelope. For these reasons one does not expect to find the vessel injuries at the level of skin disruption in scalp avulsion. They have rather to be sought further distally to the central part of the skull wound.
Surgical Repair of a Totally Avulsed Scalp
J. Cranio-Max.-Fac.Surg. 19 (1991)
Tear-Off-Direction
+
~
V
Cuffs ,/<-G~, ~ " - _ \ ~ / Subcutis w - = - f ~ l J ~
e
s
~
~
s~
•
,
e,
-
l
, ~ ~ ~f-Bone t..
Galea
--Periost
Fig.9 Schematical drawing of the skull layers.
In our case only one artery was disrupted so far proximally that it could serve for micro-anastomosis. In cases of minor central scalp avulsion it seems possible to find no vessel easily available for resupplying the scalp flap (Nurnmi and Arppe, 1971). On the other hand, regarding the arterial blood supply, the biological nature of the scalp is favourable. Only one artery completely nourishes the large skin flap. This observation confirms Miller's et al. experience (1976). It depends on an extensive system of anastomoses between the main arterial trunks. Nevertheless, two or more microsurgical repairs seem to be more valid in view of the sensitive patency rate. This is especially important in older patients with sclerotic and more fragile vessels. Our patient was young with vessels of optimal quality, so that no intimal stripping occurred and the perfusion capability was maximal. Certainly there is a correlation between the degree of sclerosis and the success rate under any circumstances. We do not, however, have any method for predicting success. Replantation should be tried therefore in every case, with regard to the alternative. The veins present less difficulty, though they could not be found before reestablishing the blood flow. Because of their thin walls, they collapse totally. When the internal pressure rises, however, they fill and the corresponding parts can easily be found because of exact localisation reference points. Depending on the low pressure as many veins as possible should be reanastomosed. Another important point is how the vessels are torn. Remember, we are not dealing with a cutting injury. So it may be possible, that the vessel wall layers are stripped off. The outer adventitia may look normal but the internal lining has broken down (intima or even media). Microscopical examination and the test for bleeding is strictly necessary. If the vessel wall layers are disrupted, the stumps have to be cut strictly back until normal conditions are reached. This usually creates a minor or wider gap between the vessel ends. These gaps have to be bridged with the help of vein grafts from the forearm or anywhere else (Miller et al., 1976). In our case the vessels were disrupted as if cut, probably dependant on the youth of the patient. In the elderly the elasticity of the media diminishes and forces the surgeon to look carefully for the stripping phenomenon.
What about the necrosis of the right lateral scalp part? Full arterial blood supply was resumed after release of the aproximator. Eventually a moist necrobiosis and later necrosis occurred without any sign of venous congestion. So it could not be blamed on the patency of the venous anastomoses. The phenomenon was described clinically as a "delayed non-reflow-phenomenon". Possible reasons are: (1) too much pressure from the surgical dressing or (2) internal tissue disruption at the capillary level.
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Regarding (1), Acland (1981) warns against faulty wound dressing technique in microsurgical free flap transfer. Every additional turn of a bandage puts an increased amount of pressure on the tissue surface. Even if every turn is very loose, the sum of the pressures can be high enough to exceed the capillary blood pressure. From this it seems reasonable to omit a dressing and leave the wound open. In the case of neck scalp avulsion one has to take the weight of the head from the replanted scalp. As Steinau (1989) recommended, a head gear is suitable for this purpose. In our patient, however, the necrosis occurred laterally in the neck region, where no external pressure was exerted. Rather, internal tissue arrangement was probably severely disturbed because the scalp was twisted round the cardan shaft very tightly and rotated there for a while. Obviously the two large missing parts were punched out by this occurrence and crushed completely, so that they could not be conserved by the emergency unit. No wonder then the surrounding parts of the scalp were severely traumatized. Lu's (1969) statement gives support to this presumption, in that he insists on avoidance of any mechanical insult to the scalp, otherwise the reanimation of the tissue would fail. The operating team, faced with such a severe but rare laceration, may be affected by apprehension reflecting more or less unconciously the future fate of the patient. The rarity of a total scalp avulsion may lead to a lack of a proper treatment-plan by the surgeon. Two of Millard's principles of plastic surgery (1986) are therefore of great importance: (1) diagnosis before treatment and (2) put normal to normal. A special surgical schedule might be helpful to cope with the problem. 1. Scrutinize the vessel situation on the skull, bearing in mind the normal anatomy of the main neuro-vascular trunks: Supraorbital, temporal and occipital, on both sides. 2. Do not worry about the veins. 3. When the arteries are identified and one or more seem suitable for micro-anastomosis, search carefully and patiently in the scalp to identify the corresponding distal portion. With the help of localisation reference you will succeed in discovering them. 4. Deal with the veins only after release of the arterial blood flow. It helps identify the vein stumps. It is much easier to find corresponding veins than arteries. 5. Do not worry about the time you need for the procedure; the scalp tissue is very tolerant of oxygen deprivation. 6. Save the cut hair tuft for a temporary wig. Finally a further aspect of revisional surgery shall be mentioned. It is possible to enlarge the hair bearing parts of the scalp with the help of tissue expanders. At present our patient is not willing to undergo such a procedure. But time will possibly change her mind. The split skin donor site was placed dorsally to get it out of sight for the girl and to be able to cover it with a swim suit. The scarred areas are going to be removed in stages over the following couple of years. So far the girl is happy and has a boyfriend, like others.
References Acland, R.: Pers. comm. 1981 Caldwell, E.H.: Complete scalp avulsion. Arch. Surg. 111 (1976) 159
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J. Cranio-Max.-Fac. Surg. 19 (1991)
Feierabend, T. C., IL N. Bindra: Injuries causing major loss of scalp. Plast. Reconstr. Surg. 76 (1985) 189 Lu, M.'. Successful replacement of avulsed scalp. Plast. Reconstr. Surg. 43 (1969) 231 Millard, D.R. jr.: Principlization of plastic surgery. Little, Brown. Boston/Toronto (1986), 149 and 160 Miller, E., D. H. Graeme, E.J. Austee, J. A. Snell: Successful replantation of an avulsed scalp by microvascular anastomoses. Plast. Reconstr. Surg. 58 (1976) 133 Nummi, P., A. Arppe: Replacement of the avulsed scalp. Scand. J. Plast. Reconstr. Surg. 5 (1971) 67 Steinau: Pets. comm. (1989)
K. Bitter, H.-P. Howaldt: Surgical Repair of a Totally Avulsed Scalp. Prof. Dr. K. Bitter, M.D., D.M.D. Johann-Wolfgang-Goethe-Universitiit Abt. Kiefer- und Gesichtschirurgie Theodor-Stern-Kai 7 W-6000 Frankfurt 70 Germany