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Surgical Repair of Cleft Palate in the Horse R. S. JONES Department of Anaesthesia, The University. P.O. Box 147, Liverpool, L69 3BX D. 0. MAISELS J. J. DE GEUS Whiston Hospital, Liverpool B. B. J. LOVlUS Dental Hospital, Liverpool
IN the horse the incidence of cleft palate is difficult to estimate but is considered to be low. PIatt (1973) over a five year period, reported two cases in 640 autopsies performed on foetuses and foals at the Equine Research Station, Newmarket, while a figure of one per 1,000 of specialised admissions to that Station was quoted by Batstone (1966). This condition receives little attention in the standard textbooks of veterinary surgery (O’Connor, 1950; Frank, 1964), although there have been at least four cases of surgical repair recorded in the literature. The first was in a seven year old saddle horse (Kendrick, 1950), the second and third in two, four month old Thoroughbreds (Batstone, 1966) and the fourth in an I I day old foal (Stickle, Gable and Braden, 1973). The only species for which reasonably accurate figures of the incidence of cleft lip and palate are available is man. In Caucasians a figure of 0.45 per 1,000 births is generally accepted for isolated cleft palate (Fraser, 1971). The mechanism of fusion of the palatal folds once they assume the horizontal position in early foetal life is such that fusion takes place rostro-caudally from the incisive foramen like a zip fastener (Hamilton, Boyd and Mossman, 1962). An interruption may occur in this process of normal fusion at any stage so that it is possible to have any degree of cleft from a complete one of both the hard and soft palates to a small cleft of the posterior part of the soft palate only. Despite a cleft in the palate the normal structures are always present in this region. Although the actual size of the parts in the immediate area of the cleft appear smaller than normal the degree of reduction in size is difficult to estimate. When the hard palate is involved there is some lateral displacement of the pterygoid plates apparently under the influence of the tongue. The presence of the muscles, even in the event of a cleft being present, means that a variable degree of function is retained and hence it is possible for horses to survive, particularly if the cleft is limited to the soft palate alone. As a general rule, however, the animal fails to thrive, showing signs of nasal discharge and escape of milk, food particles and water down one or both nostrils. Inhalation pneumonia is a common terminal event.
In human subjects clefts of the palate are repaired for two main reasons. The first is to facilitate eating and in this respect a simple repair of the cleft usually suffices. The early repairs carried out in man consisted of simple paring or freshening of the cleft margins and suturing with two or three through and through sutures (von Graefe, 1817, 1819; Roux, 1819) and recent accounts of the original reports make fascinating reading. A similar technique has been described in horses (Kendrick, 1950; Stickle, rt al., 1973). While simple paring and suturing will enable one to close clefts affecting the soft palate only, more extensive defects reaching forward into the hard palate demand more sophisticated procedures. These include raising flaps of muco-periosteum from the hard palate to permit closure of the oral layer, while repair of the nasal layer requires mobilisation of the mucosa, use of flaps from the vomer and occasionally even island flaps of oral mucosa as well (Millard, 1962). The second and main reason for repairing clefts of the human palate is to enable the patient to speak normally. To this end, certain additional factors are involved. One of the abnormal anatomical features of clefts is the attachment of each levator palati to the posterior nasal spine on that side. Thus, in order to reconstructthe normal “levator sling” which is essential if the palate is to move correctly in speech, these muscles must be dissected from their attachments to the posterior nasal spine and sutured to each other end to end in the mid line. Furthermore, the soft palate should be long enough to reach the posterior pharyngeal wall. Should it fail to do so, the velo pharyngeal sphincter will be incompetent and the nasal speech of cleft palate will result from the escape of sounds through this sphincter into the nose. Thus most surgeons aim, not only at side to side closure but also at achieving some “push back” as well. OPERATIVE REPAIR In view of the difficulties of access to the cleft and of visibility in all three of the cases reported in this paper it was decided to carry out repair by way of a mandibular symphysiotom y.
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Cuse I A fourteen day old Arab colt foal was presented with a history of difficulty in suckling and return of milk down both nostrils during and after feeding. It had been pyrexic and dull during the previous week; these symptoms were treated with penicillin and streptomycin. On general examination the foal was in good bodily condition with evidence of a bilateral nasal discharge but no abnormality of the palate could be observed whilst it was conscious. Anaesthesia was induced with nitrous oxide, oxygen and halothane' via a nasal tube. This method was modified from that described by Langley (1972) as no premedication was administered, the tip of the tube was placed in the pharynx and nitrous oxide was employed in addition to the halothane. Once anaesthesia had been induced the foal was placed in lateral recumbency and the trachea intubated via the mouth. Anaesthesia was maintained with oxygen-halothane in a closed circuit. On examination with a laryngoscope a cleft involving the greater part of the soft palate was observed. The following day anaesthesia was again induced and maintained in a similar manner. The foal was placed in dorsal recumbency and the whole of the ventral head and neck region were prepared for surgery. A tracheotomy was performed in the mid-neck region and the oral endotracheal tube was replaced by another via the tracheotomy. The electrocardiogram Lead 11 was monitored and an intravenous infusion of N/5 saline with dextrose was begun, a total of one litre being administered during the operation. The palate was approached by a mandibular symphysiotomy as described by Nelson, Curley and Kaimer (1971). This approach provided excellent access (fig. I). The cleft involved the posterior two thirds of the soft palate, extending submucouSlY into the anterior one third of the soft palate and into the posterior third of the hard palate. Caudally the edges of the cleft were incised and the dissection carried down to expose muscle in the depths of each wound. Anteriorly where the cleft was submucous only, the oral mucosa was dissected back to reveal the levator muscles passing forward to gain attachment to the posterior nasal spine. The levator muscles were freed from the bone and sutured to each Other* The 'left was repaired using interrupted sutures of 3/0 chromic catgut to close both the nasal and oral layers of the mucosa. In addition mattress sutures Of 3/O chromic catgut were On the Oral surface, care in the being taken to include the Palata1 bites Of the sutures. The symphysiotomy wound was then closed using two layers of interrupted sutures of 3/0 chromic catgut to ensure that it was water-tight. The symphysis was repaired with two wire sutures placed through the lower borders of the mandible and supplemented by interdental wiring of the lower incisors. The lip was closed with three layers of interrupted sutures in the labial mucosa, muscle and skin respectively. The rest of theskin wound was closed with polyglycolicacid suture*. R~~~~~~~from anaesthesia was rapid. The foal began to suckle the next morning and progressed well for 14 days, ~ ~ ~ itherapy b i was ~ ~given i ~for seven days, as the tracheotomy wound discharged mUCOUs and pus during this time. There was no nasal discharge or regurgitation of milk down the nostrils either during or after feeding. On the fifteenth day the foal began to lose weight, became pyrexic, showed a nasal discharge and rapid and laboured respirations. It ceased to feed on the seventeenth day and despite artificial feeding by stomach tube it died on the twentieth day.
Fig. 1. (a) view at operation showing the excellent accem. ( b ) Line drawing o f f g . l a : ( A ) The two parts ofthe soft palate showing the clefi; ( B ) Left mandibdar incisor teeth; ( C ) Right mandibular incisor teeth; ( D ) Maxillary incisor teeth; ( E ) Tongue; ( F ) Mandibular molar teeth; ( G ) Maxillary molar teeth. Post-mortem examination
The post-mortem examination showed :-A Severe pneumonia in the ventral half of both lungs; E.coli septicaemia probably subterminally. E.coli was isolated from the joints, liver, kidney and spleen. Examination of the head revealed that healing had occurred in all of the areas involved in the operation. The lip had healed well, apart from a slight notch at the muco-cutaneous junction. The symphysis had healed and the soft palate was closed. Tho floor of the mouth was intact, Cuse II A fourteen month Old filly was presented with a history of persistent bilateral nasal discharge which had been present since birth. An orphan, it had been reared artificially fmm four days of age. Oral examination was impossible in the conscious animal due to its fractious nature. The filly, which weighed 268 kg, was premedicated with 25 mg of acepromazine3 and anaesthesia was induced with 3 g ofthiopentone sodium' and 25 mg of suxamethonium chloride'. The filly was intubated with a cuffed endotracheal tube and anaesthesia was 1 "Fluothane", I.C.1. (Pharmaceuticals) Ltd.
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EQUINE VETERINARY JOURNAL
maintained with oxygen/halothane in a circle absorber. therapy. Examination under general anaesthesia by the Pharyngoscopy revealed a keyhole shaped cleft of entire referring veterinary surgeon had revealed a cleft palate. soft palate. It was allowed to recover from anaesthesia After premedication with acepromazine, anaesthesia and it was decided to repair the cleft two days later. was induced with thiopentone and suxamethonium. The filly was anaesthetised in a similar manner to the Anaesthesia was maintained with oxygen-halothane in a previous occasion, placed in dorsal recumbency and a circle absorber. On endoscopic examination a cleft intracheotomy performed as in Case I . The palate was volving the whole of the soft palate was observed. Suragain approached through a mandibular symphysiotomy gical repair was carried out seven days later. and the wound closure was carried out as in Case I. The anaesthetic and surgical procedures were similar The operative findings, this time, were somewhat to those used in Case 11. The pony did not drink on the different as the cleft involved the whole of the soft palate first post operative day and it was noted that the whole with no submucous extension into the hard palate. The of the face was slightly swollen. On the second day the most striking difference lay in the very poor musculature pony was still not drinking and the face remained swollen. found in the soft palate and in the relative excess of Intravenous therapy of five litres of N/5 saline and two mucosa and glandular tissue which gave rise to rather litres of Hartmann's solution was administered. On the redundant and floppy leaves of soft palate. Closure of third day, as the horse was still not drinking, a stomach the cleft was again effected in two layers and, as before, tube was passed via the nostrils and six litres of electroit was difficult to judge how far posteriorly to carry the lyte solution were administered twice during the day. repair in the absence of a uvula to act as a landmark. This treatment was repeated on the fourth day and by the Batstone (1966) experienced a similar difficulty. fifth, the pony was drinking and had begun to eat hay. Recovery from anaesthesia was rapid. Pethidine and From the fifth day the pony made an uncomplicated penicillin therapy was administered the following morn- recovery and the sutures were removed on the tenth day, ing. The filly drank approximately 8 litres of water to but dehiscence of the lip wound had occurred to a depth which glucose, sodium bicarbonate and sodium chloride of about 5 cm which can be attributed to the fact that it had been added, but was offered no food and was bedded was bedded on peat. on sawdust. Three months later the pony was readmitted and the This treatment was continued on the second day. lip repaired in three layers. At this time endoscopic Early that evening, however, a marked facial oedema examination showed that the palate repair was intact. developed and a temporary tracheotomy tube was in- Three months later the pony was well. serted into the original tracheotomy wound. On the DISCUSSION third day the filly was unable to drink and it was decided, with considerable misgiving, to pass a stomach tube via Although it has been suggested that the incidence of the left nostril and six litres of glucose water with electro- cleft palate in the horse may be in the region of one in one lytes were administered. In the late evening two litres thousand no accurate figure is available. I t is surprising of Hartmann's solution and one litre of N/5 saline with therefore that we have seen three cases in one year in a dextrose were given by slow intravenous injection. On total number of 551 horses, referred to the University of the fourth and fifth postoperative days, because the facial Liverpool, Veterinary Field Station. oedema was still present, the filly was given by stomach The ethics of the operation, which could possibly lead tube on three occasions each day a daily total of four to the potentiation of what may be an inheritable defect, litres of milk and eight litres of glucose/electrolyte are debatable. The optimal age for carrying out the solution, By the sixth day the oedema had subsided and operation is a matter of conjecture. The literature cites the animal began to drink freely and to eat cut grass and a successful result in an eleven day old foal (Stickle, et a/., hay. The filly steadily improved in condition and the 1973), and also one failure and a partial success in skin sutures were removed on the tenth day. The animals of four months of age (Batstone, 1966). tracheotomy wound did not close completely until the A number of different surgical approaches to the palate fourteenth day. The filly was discharged on the twen- have been described in the literature. Kendrick (1960) tieth day, when the only abnormality present was a slight used an oral approach but sutured the tongue to the base nasal discharge from the right nostril, unrelated to of the mouth to retract it. Batstone (1966) also used the feeding. oral approach and had some difficulty in obtaining Ten weeks after the operation the filly was re-admitted adequate exposure. Manchester ( 1973) described an for examination and assessment. Thefilly was in good approach through a laryngotomy incision which was then bodily condition and her weight had increased by 50 kg. extended forward into the mouth by splitting the thyroid There was no nasal discharge but there was a small sinus cartilage and dividing the epiglottis. He claimed that at the site of the tracheotomy incision. General anaes- this technique gave an excellent approach to the palate. thesia was induced and maintained as on the previous We decided to adopt the mandibular symphysiotomy occasions. On examination with a rhinolaryngoscope approach as described by Nelson, et a/. (1971) and Stickle the palate was seen to have healed satisfactorily. The ei a/. (1973) which gave a good exposure of the whole sinus over the trachea was opened and necrotic tissue palate. curetted. Penicillin was administered and on three Various suture materials have been employed to repair subsequent days. The sinus had healed in two weeks and the palate. Silk was used by Batstone (1966) and Manthe owner reported one year later that the horse con- Chester (1973), both of whom recorded either a total or tinued fit and well and had no nasal discharge. partial failure. In the case described by Manchester (1973) breakdown occurred some months after operation Case I11 and he attributed this to the use of a non-absorbable A five year old pony had been purchased six months suture material. In both of the cases described by previously. Since purchase it had shown signs of a Batstone (1966) breakdown occurred in the repaired persistent nasal discharge which had not responded to wounds. In our experience the use of chromic catgut
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follicles (fig. 2a and b). The wire sutures were supplemented by interdental wiring and stability was satisfactory. A problem was posed in the post operative care of these animals. In the case of the foal it was considered advisable that it should suckle as soon as possible after the operation and no difficulties were presented by this. In the other two cases it was decided to allow them to drink milk and electrolyte solution for the first five post operative days. In Case I1 this resulted in a dilemma when the facial oedema occurred and it could not drink. It was felt that the risk of damage to the palatal suture line was justified in order to hydrate the animal and five days later it was allowed solid food. In the event no damage was done by the stomach tube which was employed in both Cases I I and 111 in the immediate post operative period. In Case 111, which was bedded on peat, the material collected between the lower lip, gum and teeth may have been the major contributing factor to the lip wound dehiscence. SUMMARY Surgical repair of a cleft palate was carried out in three horses. Mandibular symphysiotomy allowed adequate exposure of the defect. The first subject, a young foal died from inhalation pneumonia but the other two made satisfactory recoveries. The problems of closure of the lip and symphysis are discussed. RESUME Cette correction fut tentee chez trois chevaux. On pratiqua une symphysiotomie maxillaire afin d'elargir la voie d'accis. Le premier animal mourut de pneumonie secondaire. Les deux autres animaux gutrirent. Les techniques de fermeture de la symphyse et de la ltvre sont indiqukes. ZUSAMMENFASSUNG Die chirurgische Behandlung eines Wolfsrachens wurde bei drei Pferden vorgenommen. Eine mandibd a r e Symphysiotomie erlaubte einen geniigenden Zugang zum Defekt. Der erste Patient, ein junges Fohlen, starb an einer Verschluckpneumonie, die beiden andern erholten sich befriedigend. Die Probleme des Verschlusses von Lippe und Symphyse werden diskutiert. Fig. 2. Case I1 (a) Occlusal radiograph of mandible showing wire ligature. ( b ) Lateral radiograph of the jaws. The wire ligatures can be seen lying below the roots of both the decidrroits and permanent teeth.
has resulted in successful repairs of the palate in all three cases. It was decided to close the lip in three layers because dehiscence had been reported by Nelson, et al. (197 I ) and Stickle, ef a/. (1973). No difficulties were encountered in the first two cases described in this paper but dehiscence did occur in the third case. Successful secondary repair of the lip was achieved several weeks after the original operation. The symphyseal fixation produced problems in the foal described by Stickle, et al. (1973). In the three cases described in this paper the mandible was fixed with two wire sutures through the bone and radiographs of Case I1 show that the wires do not pass through the tooth
ACKNOWLEDGEMENTS We are indebted to the horse owners for allowing us to operate on their animals and to the three referring veterinary surgeons, i.e. Messrs. T. Strachan, E. V. Thomas and H . Holroyd. Sincere thanks are due to a number of colleagues for help and encouragement particularly J . E. Cox for photography and surgical assistance, to J . F. R. Hird and D. M. Love for anaesthetic assistance, to D. F. Cotterell and F. G . R. Taylor for post operative care and to A. Leyland for the post-mortem examination. Special thanks are due to Miss A. Pitts for her skill and patience in typing the manuscript. REFERENCES Batstone, J. H . F. (1966). Cleft Palate in the Horse. Brit. J . Plast. Surg. 19, 327. Frank, E. R . (1964). Veterinary Siirgery, 7th edition, Burgess Publishing Company, Minneapolis, Minn.
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Fraser. F. C. (1971). I n Cleft Lip and Palate, Surgical, Dental and Speech Aspects. Ed.,Grabb, W. C., Rosenstein, S. W. and Bzoch, K. R. 1st edition, J. and A. Churchill, London. von Graefe, C. F. (1817). Translated and Reprinted in Plastic and Reconstructive Siirgery ( 197 I ) 47, 375. von Graefe, C. F. (1819). Translated and Reprinted in Plastic and Reconstriictive Siirgwy ( I 97 I ) 47, 488. Hamilton, W. J., Boyd, J. D. and Mossnian. H. W. (1962). Hirnian Embryology, 3rd Edition, Heffer, Cambridge. Kendrick, W. J. (1950). Cleft Palate in a Horse. Corndl Vct. 40, 188. Langley, J. (1972). Nasal Intubation as a Method of Halothane Anaesthesia. Proc. A . V . A . 3, 10. Manchester, W. M. (1973). Personal communication.
Millard, D. R. (1962). Wide and/or Short Cleft Palate. Plastic and Rcconstrrrctise Siirgwy 29, 40. Nelson, W. A., Curley, B. M. and Kainer, R. A. (1971). Mandibular Symphysiotomy to Provide Adequate Exposure in lntraoral Surgery in the Horse. Jorir. A m r . Vet. Med. Ass. 159, 1025.
O’Connor, J. (1950). Dollar’s Veterinar.v Siirgcry, 4th Edition, Bailliere, Tindall and Cox, London. Platt, H. (1973). Etiological Aspects of Perinatal Mortality in the Thoroughbred. Equine Vet. J. 5 , 116. Roux (1819) quoted by Wallace, A. B. (1966). Canadian-FrancoScottish Co-operation: A Cleft Palate Story. Brif. J. Plast. Surg. 19, I . Stickle, R. L.. Gable, D. 0. and Braden, T. D. (1973). Repair of Cleft Soft Palate i n a Foal. Vet. Mc,c/./SAC.68, 159.
ABSTRACTS Nervous System and Diseases Observations on the Coeliaco- Mesenteric Ganglia of Horses with and without Grass Sickness . 130, 265-270. HOWELL, J. McC., BAKER, J. R. and RITCHIE, H. E. (1974). Br. V P ~ J. Histological examination was performed on the coeliaco-inesenteric ganglia from 50 horses presented for post-mortem examination at Liverpool University Veterinary Field Station over a five-year period. Grass sickness had been diagnosed on clinical and gross pathological grounds in 17 of these animals, and in these, the coeliacomesenteric ganglia contained numerous degenerate, foamy and necrotic neurones (illustrated). Conditions other than grass sickness had been diagnosed in a further 32 animals, of which nine had signs and lesions involving the abdomen. In only six of these 32 animals was any neurone degeneration seen, and then only single numbers of cells were affected, none of which showed foamy changes. The one remaining horse had been destroyed after 24 hours illness and was thought to have grass sickness, but again only a few degenerate, non-foamy neurones were observed. The authors suggest that histological examination of the coeliaco-niesenteric ganglion is a useful diagnostic aid where grass sickness is suspected, and that the neuronal changes described are of direct significance in the pathogenesis of the disease. Advice is given on locating the coeliaco-mesenteric ganglion at autopsy. KATHERINE WHITWELL
Spinal Ataxia in Zebras. Comparison with the Wobbler Syndrome of Horses MONTALI, R. J., BUSH, M., SAUER, R. M., GRAY,C. W. and XANTEN, W. A., jr. (1974). Vet. Path. 11, 68-78. At least eight out of 17 Grant’s zebra foals born over a 12 year period at the National Zoological Park, Washington, D.C. suffered from ataxia. The foals were the progeny of two normal unrelated zebra mares and were by one normal zebra stallion: both male and female foals were affected. Ataxia developed insidiously at four to six months old and progressed. It mainly affected the hindlimbs but there was also some weakness of the forelegs. Hypermetria was not seen and backing was unimpaired. The authors describe the pathological findings in two affected fillies euthanased as yearlings and in one three year old colt. N o significant radiographic findings were noted in the neck, in either the natural or the flexed positions. Cervical vertebrae from two cases were examined. No narrowing of the vertebral canal was present. In one animal there was slight asymmetry of the articular processes at the C,-4 articulation. The spinal cord of all three cases showed a diffuse myelopathy of similar pattern and intensity. Bilateral deniyelination was present in both ascending and descending tracts at all levels examined. Dorsal funiculi and grey columns were normal. Tract degeneration was traced as far forward as the medulla in both cases where the brain was examined. Adventitial fibrosis of small blood vessels was present in the ventral and lateral funiculi. The 20-year old non-ataxic sire of the affected foals was also autopsied; spinal cord and cervical vertebrae were normal. Several possible causes for the niyelopathy were considered and rejected. The pathological findings differed significantly from those of the “Wobbler syndrome” in which a primary focus of cord damage, associated with abnormal cervical vertebrae, leads to a characteristic pattern of secondary Wallerian degeneration. The authors suggested that the high incidence of ataxia in sibling foals might indicate that a familial primary degeneration of the spinal cord occurs in the zebra. J. S. GILMOUR
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Surgical Repair of Cleft Palate in the Horse R. S. JONES Department of Anaesthesia, The University. P.O. Box 147, Liverpool, L69 3BX D. 0. MAISELS J. J. DE GEUS Whiston Hospital, Liverpool B. B. J. LOVlUS Dental Hospital, Liverpool
IN the horse the incidence of cleft palate is difficult to estimate but is considered to be low. PIatt (1973) over a five year period, reported two cases in 640 autopsies performed on foetuses and foals at the Equine Research Station, Newmarket, while a figure of one per 1,000 of specialised admissions to that Station was quoted by Batstone (1966). This condition receives little attention in the standard textbooks of veterinary surgery (O’Connor, 1950; Frank, 1964), although there have been at least four cases of surgical repair recorded in the literature. The first was in a seven year old saddle horse (Kendrick, 1950), the second and third in two, four month old Thoroughbreds (Batstone, 1966) and the fourth in an I I day old foal (Stickle, Gable and Braden, 1973). The only species for which reasonably accurate figures of the incidence of cleft lip and palate are available is man. In Caucasians a figure of 0.45 per 1,000 births is generally accepted for isolated cleft palate (Fraser, 1971). The mechanism of fusion of the palatal folds once they assume the horizontal position in early foetal life is such that fusion takes place rostro-caudally from the incisive foramen like a zip fastener (Hamilton, Boyd and Mossman, 1962). An interruption may occur in this process of normal fusion at any stage so that it is possible to have any degree of cleft from a complete one of both the hard and soft palates to a small cleft of the posterior part of the soft palate only. Despite a cleft in the palate the normal structures are always present in this region. Although the actual size of the parts in the immediate area of the cleft appear smaller than normal the degree of reduction in size is difficult to estimate. When the hard palate is involved there is some lateral displacement of the pterygoid plates apparently under the influence of the tongue. The presence of the muscles, even in the event of a cleft being present, means that a variable degree of function is retained and hence it is possible for horses to survive, particularly if the cleft is limited to the soft palate alone. As a general rule, however, the animal fails to thrive, showing signs of nasal discharge and escape of milk, food particles and water down one or both nostrils. Inhalation pneumonia is a common terminal event.
In human subjects clefts of the palate are repaired for two main reasons. The first is to facilitate eating and in this respect a simple repair of the cleft usually suffices. The early repairs carried out in man consisted of simple paring or freshening of the cleft margins and suturing with two or three through and through sutures (von Graefe, 1817, 1819; Roux, 1819) and recent accounts of the original reports make fascinating reading. A similar technique has been described in horses (Kendrick, 1950; Stickle, rt al., 1973). While simple paring and suturing will enable one to close clefts affecting the soft palate only, more extensive defects reaching forward into the hard palate demand more sophisticated procedures. These include raising flaps of muco-periosteum from the hard palate to permit closure of the oral layer, while repair of the nasal layer requires mobilisation of the mucosa, use of flaps from the vomer and occasionally even island flaps of oral mucosa as well (Millard, 1962). The second and main reason for repairing clefts of the human palate is to enable the patient to speak normally. To this end, certain additional factors are involved. One of the abnormal anatomical features of clefts is the attachment of each levator palati to the posterior nasal spine on that side. Thus, in order to reconstructthe normal “levator sling” which is essential if the palate is to move correctly in speech, these muscles must be dissected from their attachments to the posterior nasal spine and sutured to each other end to end in the mid line. Furthermore, the soft palate should be long enough to reach the posterior pharyngeal wall. Should it fail to do so, the velo pharyngeal sphincter will be incompetent and the nasal speech of cleft palate will result from the escape of sounds through this sphincter into the nose. Thus most surgeons aim, not only at side to side closure but also at achieving some “push back” as well. OPERATIVE REPAIR In view of the difficulties of access to the cleft and of visibility in all three of the cases reported in this paper it was decided to carry out repair by way of a mandibular symphysiotom y.
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Cuse I A fourteen day old Arab colt foal was presented with a history of difficulty in suckling and return of milk down both nostrils during and after feeding. It had been pyrexic and dull during the previous week; these symptoms were treated with penicillin and streptomycin. On general examination the foal was in good bodily condition with evidence of a bilateral nasal discharge but no abnormality of the palate could be observed whilst it was conscious. Anaesthesia was induced with nitrous oxide, oxygen and halothane' via a nasal tube. This method was modified from that described by Langley (1972) as no premedication was administered, the tip of the tube was placed in the pharynx and nitrous oxide was employed in addition to the halothane. Once anaesthesia had been induced the foal was placed in lateral recumbency and the trachea intubated via the mouth. Anaesthesia was maintained with oxygen-halothane in a closed circuit. On examination with a laryngoscope a cleft involving the greater part of the soft palate was observed. The following day anaesthesia was again induced and maintained in a similar manner. The foal was placed in dorsal recumbency and the whole of the ventral head and neck region were prepared for surgery. A tracheotomy was performed in the mid-neck region and the oral endotracheal tube was replaced by another via the tracheotomy. The electrocardiogram Lead 11 was monitored and an intravenous infusion of N/5 saline with dextrose was begun, a total of one litre being administered during the operation. The palate was approached by a mandibular symphysiotomy as described by Nelson, Curley and Kaimer (1971). This approach provided excellent access (fig. I). The cleft involved the posterior two thirds of the soft palate, extending submucouSlY into the anterior one third of the soft palate and into the posterior third of the hard palate. Caudally the edges of the cleft were incised and the dissection carried down to expose muscle in the depths of each wound. Anteriorly where the cleft was submucous only, the oral mucosa was dissected back to reveal the levator muscles passing forward to gain attachment to the posterior nasal spine. The levator muscles were freed from the bone and sutured to each Other* The 'left was repaired using interrupted sutures of 3/0 chromic catgut to close both the nasal and oral layers of the mucosa. In addition mattress sutures Of 3/O chromic catgut were On the Oral surface, care in the being taken to include the Palata1 bites Of the sutures. The symphysiotomy wound was then closed using two layers of interrupted sutures of 3/0 chromic catgut to ensure that it was water-tight. The symphysis was repaired with two wire sutures placed through the lower borders of the mandible and supplemented by interdental wiring of the lower incisors. The lip was closed with three layers of interrupted sutures in the labial mucosa, muscle and skin respectively. The rest of theskin wound was closed with polyglycolicacid suture*. R~~~~~~~from anaesthesia was rapid. The foal began to suckle the next morning and progressed well for 14 days, ~ ~ ~ itherapy b i was ~ ~given i ~for seven days, as the tracheotomy wound discharged mUCOUs and pus during this time. There was no nasal discharge or regurgitation of milk down the nostrils either during or after feeding. On the fifteenth day the foal began to lose weight, became pyrexic, showed a nasal discharge and rapid and laboured respirations. It ceased to feed on the seventeenth day and despite artificial feeding by stomach tube it died on the twentieth day.
Fig. 1. (a) view at operation showing the excellent accem. ( b ) Line drawing o f f g . l a : ( A ) The two parts ofthe soft palate showing the clefi; ( B ) Left mandibdar incisor teeth; ( C ) Right mandibular incisor teeth; ( D ) Maxillary incisor teeth; ( E ) Tongue; ( F ) Mandibular molar teeth; ( G ) Maxillary molar teeth. Post-mortem examination
The post-mortem examination showed :-A Severe pneumonia in the ventral half of both lungs; E.coli septicaemia probably subterminally. E.coli was isolated from the joints, liver, kidney and spleen. Examination of the head revealed that healing had occurred in all of the areas involved in the operation. The lip had healed well, apart from a slight notch at the muco-cutaneous junction. The symphysis had healed and the soft palate was closed. Tho floor of the mouth was intact, Cuse II A fourteen month Old filly was presented with a history of persistent bilateral nasal discharge which had been present since birth. An orphan, it had been reared artificially fmm four days of age. Oral examination was impossible in the conscious animal due to its fractious nature. The filly, which weighed 268 kg, was premedicated with 25 mg of acepromazine3 and anaesthesia was induced with 3 g ofthiopentone sodium' and 25 mg of suxamethonium chloride'. The filly was intubated with a cuffed endotracheal tube and anaesthesia was 1 "Fluothane", I.C.1. (Pharmaceuticals) Ltd.
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maintained with oxygen/halothane in a circle absorber. therapy. Examination under general anaesthesia by the Pharyngoscopy revealed a keyhole shaped cleft of entire referring veterinary surgeon had revealed a cleft palate. soft palate. It was allowed to recover from anaesthesia After premedication with acepromazine, anaesthesia and it was decided to repair the cleft two days later. was induced with thiopentone and suxamethonium. The filly was anaesthetised in a similar manner to the Anaesthesia was maintained with oxygen-halothane in a previous occasion, placed in dorsal recumbency and a circle absorber. On endoscopic examination a cleft intracheotomy performed as in Case I . The palate was volving the whole of the soft palate was observed. Suragain approached through a mandibular symphysiotomy gical repair was carried out seven days later. and the wound closure was carried out as in Case I. The anaesthetic and surgical procedures were similar The operative findings, this time, were somewhat to those used in Case 11. The pony did not drink on the different as the cleft involved the whole of the soft palate first post operative day and it was noted that the whole with no submucous extension into the hard palate. The of the face was slightly swollen. On the second day the most striking difference lay in the very poor musculature pony was still not drinking and the face remained swollen. found in the soft palate and in the relative excess of Intravenous therapy of five litres of N/5 saline and two mucosa and glandular tissue which gave rise to rather litres of Hartmann's solution was administered. On the redundant and floppy leaves of soft palate. Closure of third day, as the horse was still not drinking, a stomach the cleft was again effected in two layers and, as before, tube was passed via the nostrils and six litres of electroit was difficult to judge how far posteriorly to carry the lyte solution were administered twice during the day. repair in the absence of a uvula to act as a landmark. This treatment was repeated on the fourth day and by the Batstone (1966) experienced a similar difficulty. fifth, the pony was drinking and had begun to eat hay. Recovery from anaesthesia was rapid. Pethidine and From the fifth day the pony made an uncomplicated penicillin therapy was administered the following morn- recovery and the sutures were removed on the tenth day, ing. The filly drank approximately 8 litres of water to but dehiscence of the lip wound had occurred to a depth which glucose, sodium bicarbonate and sodium chloride of about 5 cm which can be attributed to the fact that it had been added, but was offered no food and was bedded was bedded on peat. on sawdust. Three months later the pony was readmitted and the This treatment was continued on the second day. lip repaired in three layers. At this time endoscopic Early that evening, however, a marked facial oedema examination showed that the palate repair was intact. developed and a temporary tracheotomy tube was in- Three months later the pony was well. serted into the original tracheotomy wound. On the DISCUSSION third day the filly was unable to drink and it was decided, with considerable misgiving, to pass a stomach tube via Although it has been suggested that the incidence of the left nostril and six litres of glucose water with electro- cleft palate in the horse may be in the region of one in one lytes were administered. In the late evening two litres thousand no accurate figure is available. I t is surprising of Hartmann's solution and one litre of N/5 saline with therefore that we have seen three cases in one year in a dextrose were given by slow intravenous injection. On total number of 551 horses, referred to the University of the fourth and fifth postoperative days, because the facial Liverpool, Veterinary Field Station. oedema was still present, the filly was given by stomach The ethics of the operation, which could possibly lead tube on three occasions each day a daily total of four to the potentiation of what may be an inheritable defect, litres of milk and eight litres of glucose/electrolyte are debatable. The optimal age for carrying out the solution, By the sixth day the oedema had subsided and operation is a matter of conjecture. The literature cites the animal began to drink freely and to eat cut grass and a successful result in an eleven day old foal (Stickle, et a/., hay. The filly steadily improved in condition and the 1973), and also one failure and a partial success in skin sutures were removed on the tenth day. The animals of four months of age (Batstone, 1966). tracheotomy wound did not close completely until the A number of different surgical approaches to the palate fourteenth day. The filly was discharged on the twen- have been described in the literature. Kendrick (1960) tieth day, when the only abnormality present was a slight used an oral approach but sutured the tongue to the base nasal discharge from the right nostril, unrelated to of the mouth to retract it. Batstone (1966) also used the feeding. oral approach and had some difficulty in obtaining Ten weeks after the operation the filly was re-admitted adequate exposure. Manchester ( 1973) described an for examination and assessment. Thefilly was in good approach through a laryngotomy incision which was then bodily condition and her weight had increased by 50 kg. extended forward into the mouth by splitting the thyroid There was no nasal discharge but there was a small sinus cartilage and dividing the epiglottis. He claimed that at the site of the tracheotomy incision. General anaes- this technique gave an excellent approach to the palate. thesia was induced and maintained as on the previous We decided to adopt the mandibular symphysiotomy occasions. On examination with a rhinolaryngoscope approach as described by Nelson, et a/. (1971) and Stickle the palate was seen to have healed satisfactorily. The ei a/. (1973) which gave a good exposure of the whole sinus over the trachea was opened and necrotic tissue palate. curetted. Penicillin was administered and on three Various suture materials have been employed to repair subsequent days. The sinus had healed in two weeks and the palate. Silk was used by Batstone (1966) and Manthe owner reported one year later that the horse con- Chester (1973), both of whom recorded either a total or tinued fit and well and had no nasal discharge. partial failure. In the case described by Manchester (1973) breakdown occurred some months after operation Case I11 and he attributed this to the use of a non-absorbable A five year old pony had been purchased six months suture material. In both of the cases described by previously. Since purchase it had shown signs of a Batstone (1966) breakdown occurred in the repaired persistent nasal discharge which had not responded to wounds. In our experience the use of chromic catgut
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follicles (fig. 2a and b). The wire sutures were supplemented by interdental wiring and stability was satisfactory. A problem was posed in the post operative care of these animals. In the case of the foal it was considered advisable that it should suckle as soon as possible after the operation and no difficulties were presented by this. In the other two cases it was decided to allow them to drink milk and electrolyte solution for the first five post operative days. In Case I1 this resulted in a dilemma when the facial oedema occurred and it could not drink. It was felt that the risk of damage to the palatal suture line was justified in order to hydrate the animal and five days later it was allowed solid food. In the event no damage was done by the stomach tube which was employed in both Cases I I and 111 in the immediate post operative period. In Case 111, which was bedded on peat, the material collected between the lower lip, gum and teeth may have been the major contributing factor to the lip wound dehiscence. SUMMARY Surgical repair of a cleft palate was carried out in three horses. Mandibular symphysiotomy allowed adequate exposure of the defect. The first subject, a young foal died from inhalation pneumonia but the other two made satisfactory recoveries. The problems of closure of the lip and symphysis are discussed. RESUME Cette correction fut tentee chez trois chevaux. On pratiqua une symphysiotomie maxillaire afin d'elargir la voie d'accis. Le premier animal mourut de pneumonie secondaire. Les deux autres animaux gutrirent. Les techniques de fermeture de la symphyse et de la ltvre sont indiqukes. ZUSAMMENFASSUNG Die chirurgische Behandlung eines Wolfsrachens wurde bei drei Pferden vorgenommen. Eine mandibd a r e Symphysiotomie erlaubte einen geniigenden Zugang zum Defekt. Der erste Patient, ein junges Fohlen, starb an einer Verschluckpneumonie, die beiden andern erholten sich befriedigend. Die Probleme des Verschlusses von Lippe und Symphyse werden diskutiert. Fig. 2. Case I1 (a) Occlusal radiograph of mandible showing wire ligature. ( b ) Lateral radiograph of the jaws. The wire ligatures can be seen lying below the roots of both the decidrroits and permanent teeth.
has resulted in successful repairs of the palate in all three cases. It was decided to close the lip in three layers because dehiscence had been reported by Nelson, et al. (197 I ) and Stickle, ef a/. (1973). No difficulties were encountered in the first two cases described in this paper but dehiscence did occur in the third case. Successful secondary repair of the lip was achieved several weeks after the original operation. The symphyseal fixation produced problems in the foal described by Stickle, et al. (1973). In the three cases described in this paper the mandible was fixed with two wire sutures through the bone and radiographs of Case I1 show that the wires do not pass through the tooth
ACKNOWLEDGEMENTS We are indebted to the horse owners for allowing us to operate on their animals and to the three referring veterinary surgeons, i.e. Messrs. T. Strachan, E. V. Thomas and H . Holroyd. Sincere thanks are due to a number of colleagues for help and encouragement particularly J . E. Cox for photography and surgical assistance, to J . F. R. Hird and D. M. Love for anaesthetic assistance, to D. F. Cotterell and F. G . R. Taylor for post operative care and to A. Leyland for the post-mortem examination. Special thanks are due to Miss A. Pitts for her skill and patience in typing the manuscript. REFERENCES Batstone, J. H . F. (1966). Cleft Palate in the Horse. Brit. J . Plast. Surg. 19, 327. Frank, E. R . (1964). Veterinary Siirgery, 7th edition, Burgess Publishing Company, Minneapolis, Minn.
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Fraser. F. C. (1971). I n Cleft Lip and Palate, Surgical, Dental and Speech Aspects. Ed.,Grabb, W. C., Rosenstein, S. W. and Bzoch, K. R. 1st edition, J. and A. Churchill, London. von Graefe, C. F. (1817). Translated and Reprinted in Plastic and Reconstructive Siirgery ( 197 I ) 47, 375. von Graefe, C. F. (1819). Translated and Reprinted in Plastic and Reconstriictive Siirgwy ( I 97 I ) 47, 488. Hamilton, W. J., Boyd, J. D. and Mossnian. H. W. (1962). Hirnian Embryology, 3rd Edition, Heffer, Cambridge. Kendrick, W. J. (1950). Cleft Palate in a Horse. Corndl Vct. 40, 188. Langley, J. (1972). Nasal Intubation as a Method of Halothane Anaesthesia. Proc. A . V . A . 3, 10. Manchester, W. M. (1973). Personal communication.
Millard, D. R. (1962). Wide and/or Short Cleft Palate. Plastic and Rcconstrrrctise Siirgwy 29, 40. Nelson, W. A., Curley, B. M. and Kainer, R. A. (1971). Mandibular Symphysiotomy to Provide Adequate Exposure in lntraoral Surgery in the Horse. Jorir. A m r . Vet. Med. Ass. 159, 1025.
O’Connor, J. (1950). Dollar’s Veterinar.v Siirgcry, 4th Edition, Bailliere, Tindall and Cox, London. Platt, H. (1973). Etiological Aspects of Perinatal Mortality in the Thoroughbred. Equine Vet. J. 5 , 116. Roux (1819) quoted by Wallace, A. B. (1966). Canadian-FrancoScottish Co-operation: A Cleft Palate Story. Brif. J. Plast. Surg. 19, I . Stickle, R. L.. Gable, D. 0. and Braden, T. D. (1973). Repair of Cleft Soft Palate i n a Foal. Vet. Mc,c/./SAC.68, 159.
ABSTRACTS Nervous System and Diseases Observations on the Coeliaco- Mesenteric Ganglia of Horses with and without Grass Sickness . 130, 265-270. HOWELL, J. McC., BAKER, J. R. and RITCHIE, H. E. (1974). Br. V P ~ J. Histological examination was performed on the coeliaco-inesenteric ganglia from 50 horses presented for post-mortem examination at Liverpool University Veterinary Field Station over a five-year period. Grass sickness had been diagnosed on clinical and gross pathological grounds in 17 of these animals, and in these, the coeliacomesenteric ganglia contained numerous degenerate, foamy and necrotic neurones (illustrated). Conditions other than grass sickness had been diagnosed in a further 32 animals, of which nine had signs and lesions involving the abdomen. In only six of these 32 animals was any neurone degeneration seen, and then only single numbers of cells were affected, none of which showed foamy changes. The one remaining horse had been destroyed after 24 hours illness and was thought to have grass sickness, but again only a few degenerate, non-foamy neurones were observed. The authors suggest that histological examination of the coeliaco-niesenteric ganglion is a useful diagnostic aid where grass sickness is suspected, and that the neuronal changes described are of direct significance in the pathogenesis of the disease. Advice is given on locating the coeliaco-mesenteric ganglion at autopsy. KATHERINE WHITWELL
Spinal Ataxia in Zebras. Comparison with the Wobbler Syndrome of Horses MONTALI, R. J., BUSH, M., SAUER, R. M., GRAY,C. W. and XANTEN, W. A., jr. (1974). Vet. Path. 11, 68-78. At least eight out of 17 Grant’s zebra foals born over a 12 year period at the National Zoological Park, Washington, D.C. suffered from ataxia. The foals were the progeny of two normal unrelated zebra mares and were by one normal zebra stallion: both male and female foals were affected. Ataxia developed insidiously at four to six months old and progressed. It mainly affected the hindlimbs but there was also some weakness of the forelegs. Hypermetria was not seen and backing was unimpaired. The authors describe the pathological findings in two affected fillies euthanased as yearlings and in one three year old colt. N o significant radiographic findings were noted in the neck, in either the natural or the flexed positions. Cervical vertebrae from two cases were examined. No narrowing of the vertebral canal was present. In one animal there was slight asymmetry of the articular processes at the C,-4 articulation. The spinal cord of all three cases showed a diffuse myelopathy of similar pattern and intensity. Bilateral deniyelination was present in both ascending and descending tracts at all levels examined. Dorsal funiculi and grey columns were normal. Tract degeneration was traced as far forward as the medulla in both cases where the brain was examined. Adventitial fibrosis of small blood vessels was present in the ventral and lateral funiculi. The 20-year old non-ataxic sire of the affected foals was also autopsied; spinal cord and cervical vertebrae were normal. Several possible causes for the niyelopathy were considered and rejected. The pathological findings differed significantly from those of the “Wobbler syndrome” in which a primary focus of cord damage, associated with abnormal cervical vertebrae, leads to a characteristic pattern of secondary Wallerian degeneration. The authors suggested that the high incidence of ataxia in sibling foals might indicate that a familial primary degeneration of the spinal cord occurs in the zebra. J. S. GILMOUR
