EQUINE VETERINARY JOURNAL
468
Equine vet. J . (1992) 24 (6) 468-47 1
Outcome of treatment in 23 horses with progressive ethmoidal haematoma T. R. C. GREET Beaufort Cottage Stables, High Street, Newmarket, Suffolk CB8 8JS, UK.
Summary This paper describes the outcome of treatment in 23 horses with an ethmoidal haematoma. In 22 cases a diagnosis could be made by endoscopic means alone but in 1 horse the lesion was confined to the maxillary sinus and a diagnosis was made only at surgery. One horse was destroyed at the owner's request but the other 22 underwent radical excision of the lesion via a facial flap approach under general anaesthesia. Post-operative haemorrhage was controlled by nasal packing with a gauze bandage and this was removed between the 2nd and 4th post-operative day. One horse died from encephalitis the day after surgery. Other complications included facial wound dehiscence, sequestration and suture periostitis. Of 21 horses followed up post-operatively there was definite recurrence of lesion in 2 cases and possibly a third. However, in 18 horses there was no evidence of recurrence (follow up times were 2 to 85 months). It is suggested that radical excision of the lesion provides an effective means of treatment. Introduction Progressive ethmoidal haematoma, first described by Cook and Littlewort (1974) has subsequently been recognised as one of the more common causes of nasal haemorrhage in the horse (Boles 1979; Haynes 1984; Greet 1985). Typical signs are unilateral epistaxis, nasal discharge and sometimes nasal obstruction. The diagnosis can usually be made readily by endoscopy when a reddish green or yellowish green encapsulated mass is observed in the ethmoid region. The surface may show petechial haemorrhages or even superficial erosion. The mass may extend ventrally into the nasal passages and nasopharynx or expand into the paranasal sinuses pursing the line of least resistance. Although the lesion usually originates in the ethmoidal or sphenopalatine sinuses some lesions develop in the maxillary sinuses (Cook and Littlewort 1974; Sullivan er ai. 1984; Gibbs and Lane 1987). Radical excision has been reported as the treatment of choice although the recurrence rate may be as high as 50% (Cook and Littlewort 1974). This paper describes the diagnosis, treatment and outcome in 23 horses with progressive ethmoidal haematomata between 1979 and 1991.
radiography was used only as a means of assessing the extent of the lesion before surgery. In Horse 1 there was swelling of the turbinates and a mucopurulent discharge from the ostium of the maxillary sinus but no visible lesion in the ethmoid region. Lateral radiographic views of the head revealed a radiodense mass in the caudal maxillary sinus and the diagnosis was confirmed at surgery. In Horse 2 a typical haematoma was noted in the middle meatus but not in the ethmoid region. A lateral radiographic view of the head confirmed a large radiodense mass in the rostra1 margin. In 5 horses the lesion had expanded into the nasal passages and nasopharynx to such an extent that it could be seen without TABLE 1: Details of the horses in the present study
Horse Age
(years)
Breed
1 2 3 4 5 6 7 8 9 10 11 12 13
11 7 6 9 14 8 7 8 12 9 7 11 3
TB TB
14 15 16 17 18 19(i) (ii) 20 21
8 18 15 5 7 11
X X X
13 8
TB
22
7
314 TB
TB TB
Sex M
G G G M
X
G
TB
M
X
G G G G G
TB X X X X
TB TB X
M
G G G G G G
X
M M
X
M
23
7
TB
E, Ob E, N D E, ND, Ob E, ND, Ob E E E, ND E E, N D E E E E, ND E, ND E, ND, Ob E, ND, Ob E E E E E, ND E E (L 1 year
bilateral 1 month)
Diagnosis Twenty-three horses were referred for investigation of epistaxis (Table 1). An endoscopic examination of the upper respiratory tract was canied out in each case. In 22 horses typical lesions were seen endoscopically associated with the ethmoid region, permitting a provisional diagnosis by endoscopic means alone. Although lateral radiographic views of the head were obtained for most horses and dorsoventral or ventrodorsal views for a few,
Presenting signs
M
Sitelsize of lesion L, max.sinus L, typical L, typical L, typical R, 2 masses L, large L, typical L, typical L, typical L, typical
L, large R, typical L, present on both sides of nasal septum L, typical L, large R, 2 large masses R, typical L, typical R, typical L, typical L, large R, middle nasal meatuskinus L, large R, typical
E (L 2 years L, 2 masses R, typical
bilateral 6 months). Ob ~
~~
~~~
~
TB, Thoroughbred; X, cross-bred; M, mare; G, gelding; E, epistaxis; ND, nasal discharge; Ob, nasal obstruction; L, left; R, right; max., maxillary;typical, implies of average size and in the characteristic site in the ethmoid region
469
EQUINE VETERINARY JOURNAL
Surgery
Fig I : Sagittal section of head of Horse 4 post mortem showing large ethmoidal haematoma. The haematoma has originated from the ethmoidal and sphenopalative sinuses
TABLE 2: Outcome of surgery -
~~~
Horse Outcome
(a) 2 4 16 17 19 (b) 1 6 7 8 11 13 (c)
3 5 15
(4 9 10 12 14 18 20 21 22 23
Death or recurrence (post-operative period) (25%) Recurrence and euthanasia (7 months) Euthanasia without surgery Possible contralateral recurrence but doing well clinically (32 months) Died 24 h post-operatively Recurred on contralateral side, re-operated (13 months) No recurrence before being lost to follow up (26%) 7 months 12 months 2 months Average 21 months follow up 42 months 6 months 48 months No recurrence;euthanasia carried out for other reasons (13%) 72 months Average 64 months follow up 84 months 36 months No recurrence:stlll in owner's possession(39%) 85 months 77 months 66 months 44 months Average 36 months follow up 20 months 14 months 12 months 5 months 3 months
F
3
difficulty by endoscopy from the contralateral nasal passages. In Horse 13 a large lesion originating from the left ethmoid region extended equally on both sides of the nasal septum. Horse 5 had two lesions originating from one ethmoid region, Horse 23 had two lesions on one side and one on the other and Horse 22 had a single lesion bilaterally.
Treatment Horse 4 with a large single lesion (Fig 1) was destroyed at the owners request once the diagnosis had been made.
In the other 22 cases radical surgical excision of the lesion was carried out. This was performed through a frontomaxillary bone flap, with the horse under general anaesthesia in lateral recumbency with the affected side uppermost. Various methods of sedation and induction of general anaesthesia were used during the period under review. Each horse was intubated and anaesthesia maintained using a mixture of halothane and oxygen. Routine haematological and blood biochemical analyses were performed before surgery and blood was cross-matched with that of other horses to facilitate a transfusion if this became necessary; this was not used however. Intra-arterial blood pressure monitoring was used in most cases and continuous intravenous polyionic fluids (Hartmann's and 5% (w/v) hypertonic saline) administered throughout surgery. In recent years dobutamine was administered intravenously to effect if arterial blood pressure dropped significantly (ie below 80 mmHg). In 20 horses the lesion was approached by a curved skin incision and a frontomaxillary bone flap was created. In Horses 22 and 23 with a primary bilateral lesion, an 'Iyshaped' skin incision was made over the frontal region and two separate bone flaps were created to approach the lesions. In Horses 1 and 21 the lesion was contained mostly within the maxillary sinuses appearing to originate from the sinus lining. A considerable portion of the large mass in Horse 6 was found in the frontal sinus although its origin was from the ethmoid region. In the other cases the haematoma had to be retrieved from the ethmoid region, with their extensions into the nasal passages or nasopharynx. The precise origin of the lesion was usually difficult to ascertain because such sites are relatively inaccessible. The haematoma was isolated from surrounding mucosa by digital dissection and removed by careful traction from its origin. This was usually associated with moderate or severe haemorrhage which origifiated from the haematoma itself or more often from damage to surrounding turbinate tissue. Temporary bilateral carotid artery occlusion (Wyn-Jones et al. 1986) was used in Horse 13 but did not appear to reduce haemorrhage significantly. The base of the haematoma was subjected to gentle curettage using gauze swabs held by large curved forceps which enabled even the ethmoidal and sphenopalatine sinuses to be treated via the bone flap incision. This gently abrasive procedure was carried out until the surgeon judged that all haematoma tissue had been removed. The surgery was performed as rapidly as possible to minimise blood loss and haemorrhage controlled by pressure and suction. In each case the tissue removed consisted of a fibrous capsule containing dark clotted blood and was submitted for histological examination. The sinus was packed in each horse with sterile gauze bandage. This was contained within a muslin or elastic bag to prevent aspiration of the material which might result from loss of the normal turbinate architecture (Cook and Littlewort 1974). The bone flap was discarded and the periosteum preserved. This was was sutured with subcutaneous tissues in a continuous pattern using absorbable material. The bandage material was allowed to exit through the facial wound. The skin was closed using simple interrupted sutures or skin staples. Although the sinus was packed firmly until no more bandage could be inserted this did not always result in complete cessation of haemorrhage. The quantity of haemorrhage was so severe in Horse 15 that the sinus had to be re-packed before the horse was allowed to recover from anaesthesia. During recovery from general anaesthesia an intranasal tube was used (often up both nostrils) after the endotracheal tube had been removed to ensure a satisfactory airway. A temporary tracheostomy tube was inserted in the 2 horses with bilateral lesions had removed after removal of the nasal packing.
EQUINE VETERINARY JOURNAL
470
Aftercare
Pre-operative or intra-operative procaine penicillin and antitetanus therapy was administered when appropriate. Intraoperative or post-operative phenylbutazone or flunixin meglumine was administered to each case. Antibiotic cover and non-steroidal anti-inflammatory treatment were maintained for at least 5 days and longer if there was a problem with the facial wound. In most horses the nasal packing was removed either piecemeal between the 2nd and 4th post-operative days or in its entirety on the 3rd or 4th post-operative day. In Horse 5 the packing was removed in its entirety on the 3rd post-operative day with resultant severe haemorrhage necessitating repacking under a second general anaesthetic. Complications
The most severe post-operative complication was encountered in Horse 17 which died 24 h after surgery having shown severe depression and ataxia. An encephalitis related to the surgical site was found at post-mortem examination, presumably the result of surgical trauma or infection through the cribriform plate. Typically horses had a serosanguinous nasal discharge for 3-4 weeks post-operatively which subsequently resolved, although in 2 horses a mucoid nasal discharge persisted for 1 year postoperatively. In 3 horses fungal plaques were noted in the sinus between 3 and 7 months post-operatively. These were considered to be opportunistic infections following surgical trauma or postoperative lavage with antiseptic solutions. In the first 2 horses sinus lavage with an antiseptic solution was carried out for 10-14 days after packing removal but not in subsequent cases. A persistent facial discharge in Horses 22 and 23 was associated with a small bone sequestrum from the bone flap which was removed easily. In 3 horses (Nos 5, 22 and 23) there was partial wound dehiscence but this resulted in no long-term blemish. In 4 horses (Nos 1, 3, 7 and 12) there was a marked suture periostitis presumed to be the result of disruption of the facial bones but which caused no clinical problems. In most horses facial flap healing was uneventful although a slight depression was noted at the surgical site after some months.
Outcome All referring veterinary surgeons and when possible owners were requested to complete a questionnaire. These data were combined with information from follow-up examinations to determine the post-operative outcome (Table 2a-d). Except for the horse destroyed without surgery and the one which died because of post-operative encephalitis all other horses were returned to their pre-operative preoperative function within 4 months of surgery. Many horses were re-examined endoscopically, several on frequent occasions. In all horses severe alteration and distortion of the turbinate architecture were noted as a result of surgery. In 3 horses (Nos 1, 5 and 21) fungal plaques were noted. Only in Horse 5 was this associated with a foul-smelling nasal discharge which gradually resolved within 12 months of surgery without treatment. Six horses had shown no signs of recurrence before being sold or lost to follow up (Table 2b). The range of follow-up times in these cases was 2 to 48 months (average 21 months). Although some horses were sold because of the owner's concern about recurrence there was no evidence that any horse was sold having shown signs of recurrence. Horses 3, 5, and 15 had shown no signs of post-operative recurrence by 72, 84 and 36 months respectively (average 64 months) before euthanasia was carried out for unrelated reasons. Nine horses were still in the original ownership without signs of recurrence and the range of follow up times was 3 to 85 months (average 36 months).
Horse 2 returned to eventing but within 7 months had become lame with navicular disease and had clinical and endoscopic signs of recurrence of the haematoma. Euthanasia was performed and a post-mortem examination revealed the lesion to have recurred and grown into the nasopharynx. Horse 19 had a right-sided haematoma and at the time of surgery there was no endoscopic evidence of a left-sided lesion. However, within 13 months leftsided epistaxis occurred associated with a typical lesion on the left side. There was no recurrence of the original right-sided lesion. The left-sided lesion was operated on but a post-operative endoscopic examination 2 months later revealed a small regrowth on this side. This lesion was treated with a YAG laser under endoscopic control and the horse has returned to full exercise although it is too soon to assess the effects of the third operation. It is also possible that Horse 16 had developed a contralateral lesion. Having remained without signs for 12 months after surgery there were 3 episodes of slight left-sided epistaxis and an intermittent nasal discharge over the subsequent 20 months. However, the horse was still in full work and the owner would not permit a follow up endoscopic examination. Discussion The history of unilateral (bilateral) epistaxis, nasal discharge and, in horses with very large lesions, nasal obstruction was consistent with previous descriptions (Cook and Littlewort 1974; Boles 1979; Haynes 1984; Greet 1985; Specht et al. 1990). A characteristic lesion was recognised in the ethmoid region of all horses except Horses 1 and 21. In the latter a typical lesion was noted in the middle nasal meatus but in the former only turbinate enlargement with a mucopurulent discharge from the sinus ostium was recognised. Lesions originating in the maxillary sinuses have been reported previously (Cook and Littlewort 1974; Sullivan et a / . 1984; Gibbs and Lane 1987). Radiographic examination was a useful aid in assessing the size and extent of the lesion (Boles 1979; Gibbs and Lane 1987) but in this series a provisional diagnosis could be made in 22 horses on endoscopic grounds alone. Radical surgical excision as described in all previous reports (Cook and Littlewort 1974; Bonfig 1989; Specht et al. 1990) was found to be an effective means of removing the lesion although always associated with moderate or severe haemorrhage. No attempt was made to use cryosurgery as reported previously (Cook and Littlewort 1974; Specht et a/. 1990). Suction was found invaluable although visibility was always difficult because of limited access. Blind gentle curettage using gauze swabs was used to eliminate smaller remnants after the bulk of the lesion had been removed. One horse died from encephalitis presumably as a result of this procedure and surgeons must be aware of this potential complication. Temporary carotid ligation has been advocated to reduce intraoperative haemorrhage during nasal surgery (Wyn-Jones et a/. 1986) but was not found to be effective in the one horse for which it was used and it added significantly to surgical time. Although a source of cross-matched blood was available for each horse it was not found to be necessary. By contrast Specht et a / . (1990) administered cross-matched blood to 8 out of 9 operated horses. Arterial blood pressure monitoring combined with dobutamine supplementation when necessary and continuous infusion with polyionic fluids were used throughout general anaesthesia to maintain arterial blood pressure within normal limits. Surgical speed was considered invaluable in minimising blood loss. Nasal packing with gauze bandage was effective in reducing post-operative haemorrhage although in most horses a degree of haemorrhage persisted after packing. In one horse this was so severe that sinus packing had to be repeated. Nasal tubes improved airflow after removal of the endotracheal tube and therefore produced a smoother recovery from anaesthesia. A tracheostomy tube was used in 2 horses with a bilateral lesion and
EQUINE VETERINARY JOURNAL
47 I
is recommended for bilateral cases where nasal packing would otherwise produce post-operative dyspnoea. Removal of the packing between the 2nd and 4th post-operative day was associated with significant haemorrhage in only one horse in which the wound had to be repacked under a second general anaesthetic. In this horse the circulating red cell count was 2 x 1012/litreand the packed cell volume was 9%. Other than the horse which died, post-operative complications were relatively minor but included facial wound dehiscence, suture periostitis and facial bone sequestration. None of these caused a persistent problem. A post-operative nasal discharge was present for several weeks in most horses but in 2 cases it persisted for 1 year. Fungal plaques were found in 3 horses and presumed to be opportunistic infections (Greet 1981). The lesion definitely recurred in 1 horse on the operated side and probably recurred in 2 others on the contralateral side, However, in 18 other horses there was no evidence of regrowth. Unfortunately 6 horses were lost to follow up but if 12 months is used to the minimum useful follow-up period 13 horses were clear at this stage. Nine horses were clear at 24 and 36 months post-operatively. Cook and Littlewort (1974) reported on 13 cases of which there was a recurrence in 5 and Specht et a/. (1990) reported on 9 cases of which 4 suffered a recurrence of the lesion. Bonfig (1989) using a similar surgical technique reported no recurrence in 10 out of 13 cases followed up over a 6-84-month postoperative period. Assessing accurate success rates following surgical excision of an ethmoidal haematoma is very difficult for various reasons; principally because horses may be sold because of owner concern about the recurrence of the lesion. There are few published guidelines about the length of time after which recurrence of the lesion is unlikely. From the present series the success rate following radical excision appears to be 78%, similar to the results of Bonfig (1989). However, all surveys of this nature must be qualified by the time scale of follow up. In all cases the histological appearance of the lesion was as
reported by Platt (1975) but the aetiology remains obscure. Although the lesion acts in a neoplastic manner there is little histological evidence to support this aetiology.
Acknowledgements I am grateful to all the veterinary surgeons for referring the cases, completing questionnaires and providing follow-up information and in particular to Ian Wright and the Cambridge Veterinary School to whom Horse 13 was referred; to my colleagues at Beaufort Cottage Stables and the Animal Health Trust who administered general anaesthesia to the horses and generally helped with the cases; and to Niamh Nash for typing the manuscript.
References Boles, C. (1979) Abnormalities of the upper respiratory tract. Vet. Clin. N. Am. LorgeAnimal Pracr. 1.89-111. Bonfig. H. (1989) Diagnose und Therapie des progressiven Hamatoms der Siebbeinregion - dargestellt an 13 Klinischen Fallen. Pferdeheilkunde 5.71-79. Cwk. W.R. and Littlewort, M.C.G. (1974) Progressive haematoma of the ethmoid region in the horse. Equine vcr. J. 6, 101-108. Gibbs. C. and Lane, J.G. (1987) Radiographic examination of the facial nasal and paranasal sinus regions of the horse. 11 Radiological findings. Equine ver. J. 19. 474-482. Greet, T.R.C. (1981) Nasal aspergillosis in three horses. Vet.Rec. 109,487-489. Greet, T.R.C. (1985) The respiratory tract. In: Equine Surgery and Medicine. Ed: J. Hickman. Academic Press, London. p 266. Haynes. P.F. (1984) Surgery of the equine respiratory tract. In: Practice of .!.urge Animal Surgery. Ed: P.B. Jennings. W.B. Saunders Co.. Philadelphia p 404. Platt (1975) Nasal polyps of the horse. J. Pathol. 115,5 1-55. Specht. T.E., Colahan, P.T., Nixon. A.J., Brown, M.P., Turner, T.A., Peyton, L.C. and Schneider, R.K. (1990) Ethmoidal haematoma in nine horses. J. Am. vet. med. Ass. 197.613-616. Sullivan. M., Burrell. M.H. and McCandlish. I.A.P. (1984) Progressive haematoma of the maxillary sinus. Vet. Rec. 114. 191-192. Wyn-Jones. G.. Jones, R.S. and Church, S. (1986)Temporary bilateral carotid artery occlusion as an aid to nasal surgery in the horse Equine vet. J. 18. 125-128.
Received for puhlication: 13.1.92 Accepted: 23.4.92
FIELDINVESTIGATION OF GRASS SICKNESS An epidemiological study of grass sickness has recently been launched. As a questionnaire based case control study, it aims to determine more accurately the geographical distribution of the disease in Great Britain and to quantify the importance of different predisposing factors.
II
If veterinary surgeons diagnose grass sickness in an animal under their care, please could they or the owner contact eitherJames Wood (Animal Health Trust, 0638-66111 1) or Kevin Scott (Equine Grass Sickness Fund 031-664-3262),Owners will then, in confldence, be sent simple questionnaires for completion.
1
468
Equine vet. J . (1992) 24 (6) 468-47 1
Outcome of treatment in 23 horses with progressive ethmoidal haematoma T. R. C. GREET Beaufort Cottage Stables, High Street, Newmarket, Suffolk CB8 8JS, UK.
Summary This paper describes the outcome of treatment in 23 horses with an ethmoidal haematoma. In 22 cases a diagnosis could be made by endoscopic means alone but in 1 horse the lesion was confined to the maxillary sinus and a diagnosis was made only at surgery. One horse was destroyed at the owner's request but the other 22 underwent radical excision of the lesion via a facial flap approach under general anaesthesia. Post-operative haemorrhage was controlled by nasal packing with a gauze bandage and this was removed between the 2nd and 4th post-operative day. One horse died from encephalitis the day after surgery. Other complications included facial wound dehiscence, sequestration and suture periostitis. Of 21 horses followed up post-operatively there was definite recurrence of lesion in 2 cases and possibly a third. However, in 18 horses there was no evidence of recurrence (follow up times were 2 to 85 months). It is suggested that radical excision of the lesion provides an effective means of treatment. Introduction Progressive ethmoidal haematoma, first described by Cook and Littlewort (1974) has subsequently been recognised as one of the more common causes of nasal haemorrhage in the horse (Boles 1979; Haynes 1984; Greet 1985). Typical signs are unilateral epistaxis, nasal discharge and sometimes nasal obstruction. The diagnosis can usually be made readily by endoscopy when a reddish green or yellowish green encapsulated mass is observed in the ethmoid region. The surface may show petechial haemorrhages or even superficial erosion. The mass may extend ventrally into the nasal passages and nasopharynx or expand into the paranasal sinuses pursing the line of least resistance. Although the lesion usually originates in the ethmoidal or sphenopalatine sinuses some lesions develop in the maxillary sinuses (Cook and Littlewort 1974; Sullivan er ai. 1984; Gibbs and Lane 1987). Radical excision has been reported as the treatment of choice although the recurrence rate may be as high as 50% (Cook and Littlewort 1974). This paper describes the diagnosis, treatment and outcome in 23 horses with progressive ethmoidal haematomata between 1979 and 1991.
radiography was used only as a means of assessing the extent of the lesion before surgery. In Horse 1 there was swelling of the turbinates and a mucopurulent discharge from the ostium of the maxillary sinus but no visible lesion in the ethmoid region. Lateral radiographic views of the head revealed a radiodense mass in the caudal maxillary sinus and the diagnosis was confirmed at surgery. In Horse 2 a typical haematoma was noted in the middle meatus but not in the ethmoid region. A lateral radiographic view of the head confirmed a large radiodense mass in the rostra1 margin. In 5 horses the lesion had expanded into the nasal passages and nasopharynx to such an extent that it could be seen without TABLE 1: Details of the horses in the present study
Horse Age
(years)
Breed
1 2 3 4 5 6 7 8 9 10 11 12 13
11 7 6 9 14 8 7 8 12 9 7 11 3
TB TB
14 15 16 17 18 19(i) (ii) 20 21
8 18 15 5 7 11
X X X
13 8
TB
22
7
314 TB
TB TB
Sex M
G G G M
X
G
TB
M
X
G G G G G
TB X X X X
TB TB X
M
G G G G G G
X
M M
X
M
23
7
TB
E, Ob E, N D E, ND, Ob E, ND, Ob E E E, ND E E, N D E E E E, ND E, ND E, ND, Ob E, ND, Ob E E E E E, ND E E (L 1 year
bilateral 1 month)
Diagnosis Twenty-three horses were referred for investigation of epistaxis (Table 1). An endoscopic examination of the upper respiratory tract was canied out in each case. In 22 horses typical lesions were seen endoscopically associated with the ethmoid region, permitting a provisional diagnosis by endoscopic means alone. Although lateral radiographic views of the head were obtained for most horses and dorsoventral or ventrodorsal views for a few,
Presenting signs
M
Sitelsize of lesion L, max.sinus L, typical L, typical L, typical R, 2 masses L, large L, typical L, typical L, typical L, typical
L, large R, typical L, present on both sides of nasal septum L, typical L, large R, 2 large masses R, typical L, typical R, typical L, typical L, large R, middle nasal meatuskinus L, large R, typical
E (L 2 years L, 2 masses R, typical
bilateral 6 months). Ob ~
~~
~~~
~
TB, Thoroughbred; X, cross-bred; M, mare; G, gelding; E, epistaxis; ND, nasal discharge; Ob, nasal obstruction; L, left; R, right; max., maxillary;typical, implies of average size and in the characteristic site in the ethmoid region
469
EQUINE VETERINARY JOURNAL
Surgery
Fig I : Sagittal section of head of Horse 4 post mortem showing large ethmoidal haematoma. The haematoma has originated from the ethmoidal and sphenopalative sinuses
TABLE 2: Outcome of surgery -
~~~
Horse Outcome
(a) 2 4 16 17 19 (b) 1 6 7 8 11 13 (c)
3 5 15
(4 9 10 12 14 18 20 21 22 23
Death or recurrence (post-operative period) (25%) Recurrence and euthanasia (7 months) Euthanasia without surgery Possible contralateral recurrence but doing well clinically (32 months) Died 24 h post-operatively Recurred on contralateral side, re-operated (13 months) No recurrence before being lost to follow up (26%) 7 months 12 months 2 months Average 21 months follow up 42 months 6 months 48 months No recurrence;euthanasia carried out for other reasons (13%) 72 months Average 64 months follow up 84 months 36 months No recurrence:stlll in owner's possession(39%) 85 months 77 months 66 months 44 months Average 36 months follow up 20 months 14 months 12 months 5 months 3 months
F
3
difficulty by endoscopy from the contralateral nasal passages. In Horse 13 a large lesion originating from the left ethmoid region extended equally on both sides of the nasal septum. Horse 5 had two lesions originating from one ethmoid region, Horse 23 had two lesions on one side and one on the other and Horse 22 had a single lesion bilaterally.
Treatment Horse 4 with a large single lesion (Fig 1) was destroyed at the owners request once the diagnosis had been made.
In the other 22 cases radical surgical excision of the lesion was carried out. This was performed through a frontomaxillary bone flap, with the horse under general anaesthesia in lateral recumbency with the affected side uppermost. Various methods of sedation and induction of general anaesthesia were used during the period under review. Each horse was intubated and anaesthesia maintained using a mixture of halothane and oxygen. Routine haematological and blood biochemical analyses were performed before surgery and blood was cross-matched with that of other horses to facilitate a transfusion if this became necessary; this was not used however. Intra-arterial blood pressure monitoring was used in most cases and continuous intravenous polyionic fluids (Hartmann's and 5% (w/v) hypertonic saline) administered throughout surgery. In recent years dobutamine was administered intravenously to effect if arterial blood pressure dropped significantly (ie below 80 mmHg). In 20 horses the lesion was approached by a curved skin incision and a frontomaxillary bone flap was created. In Horses 22 and 23 with a primary bilateral lesion, an 'Iyshaped' skin incision was made over the frontal region and two separate bone flaps were created to approach the lesions. In Horses 1 and 21 the lesion was contained mostly within the maxillary sinuses appearing to originate from the sinus lining. A considerable portion of the large mass in Horse 6 was found in the frontal sinus although its origin was from the ethmoid region. In the other cases the haematoma had to be retrieved from the ethmoid region, with their extensions into the nasal passages or nasopharynx. The precise origin of the lesion was usually difficult to ascertain because such sites are relatively inaccessible. The haematoma was isolated from surrounding mucosa by digital dissection and removed by careful traction from its origin. This was usually associated with moderate or severe haemorrhage which origifiated from the haematoma itself or more often from damage to surrounding turbinate tissue. Temporary bilateral carotid artery occlusion (Wyn-Jones et al. 1986) was used in Horse 13 but did not appear to reduce haemorrhage significantly. The base of the haematoma was subjected to gentle curettage using gauze swabs held by large curved forceps which enabled even the ethmoidal and sphenopalatine sinuses to be treated via the bone flap incision. This gently abrasive procedure was carried out until the surgeon judged that all haematoma tissue had been removed. The surgery was performed as rapidly as possible to minimise blood loss and haemorrhage controlled by pressure and suction. In each case the tissue removed consisted of a fibrous capsule containing dark clotted blood and was submitted for histological examination. The sinus was packed in each horse with sterile gauze bandage. This was contained within a muslin or elastic bag to prevent aspiration of the material which might result from loss of the normal turbinate architecture (Cook and Littlewort 1974). The bone flap was discarded and the periosteum preserved. This was was sutured with subcutaneous tissues in a continuous pattern using absorbable material. The bandage material was allowed to exit through the facial wound. The skin was closed using simple interrupted sutures or skin staples. Although the sinus was packed firmly until no more bandage could be inserted this did not always result in complete cessation of haemorrhage. The quantity of haemorrhage was so severe in Horse 15 that the sinus had to be re-packed before the horse was allowed to recover from anaesthesia. During recovery from general anaesthesia an intranasal tube was used (often up both nostrils) after the endotracheal tube had been removed to ensure a satisfactory airway. A temporary tracheostomy tube was inserted in the 2 horses with bilateral lesions had removed after removal of the nasal packing.
EQUINE VETERINARY JOURNAL
470
Aftercare
Pre-operative or intra-operative procaine penicillin and antitetanus therapy was administered when appropriate. Intraoperative or post-operative phenylbutazone or flunixin meglumine was administered to each case. Antibiotic cover and non-steroidal anti-inflammatory treatment were maintained for at least 5 days and longer if there was a problem with the facial wound. In most horses the nasal packing was removed either piecemeal between the 2nd and 4th post-operative days or in its entirety on the 3rd or 4th post-operative day. In Horse 5 the packing was removed in its entirety on the 3rd post-operative day with resultant severe haemorrhage necessitating repacking under a second general anaesthetic. Complications
The most severe post-operative complication was encountered in Horse 17 which died 24 h after surgery having shown severe depression and ataxia. An encephalitis related to the surgical site was found at post-mortem examination, presumably the result of surgical trauma or infection through the cribriform plate. Typically horses had a serosanguinous nasal discharge for 3-4 weeks post-operatively which subsequently resolved, although in 2 horses a mucoid nasal discharge persisted for 1 year postoperatively. In 3 horses fungal plaques were noted in the sinus between 3 and 7 months post-operatively. These were considered to be opportunistic infections following surgical trauma or postoperative lavage with antiseptic solutions. In the first 2 horses sinus lavage with an antiseptic solution was carried out for 10-14 days after packing removal but not in subsequent cases. A persistent facial discharge in Horses 22 and 23 was associated with a small bone sequestrum from the bone flap which was removed easily. In 3 horses (Nos 5, 22 and 23) there was partial wound dehiscence but this resulted in no long-term blemish. In 4 horses (Nos 1, 3, 7 and 12) there was a marked suture periostitis presumed to be the result of disruption of the facial bones but which caused no clinical problems. In most horses facial flap healing was uneventful although a slight depression was noted at the surgical site after some months.
Outcome All referring veterinary surgeons and when possible owners were requested to complete a questionnaire. These data were combined with information from follow-up examinations to determine the post-operative outcome (Table 2a-d). Except for the horse destroyed without surgery and the one which died because of post-operative encephalitis all other horses were returned to their pre-operative preoperative function within 4 months of surgery. Many horses were re-examined endoscopically, several on frequent occasions. In all horses severe alteration and distortion of the turbinate architecture were noted as a result of surgery. In 3 horses (Nos 1, 5 and 21) fungal plaques were noted. Only in Horse 5 was this associated with a foul-smelling nasal discharge which gradually resolved within 12 months of surgery without treatment. Six horses had shown no signs of recurrence before being sold or lost to follow up (Table 2b). The range of follow-up times in these cases was 2 to 48 months (average 21 months). Although some horses were sold because of the owner's concern about recurrence there was no evidence that any horse was sold having shown signs of recurrence. Horses 3, 5, and 15 had shown no signs of post-operative recurrence by 72, 84 and 36 months respectively (average 64 months) before euthanasia was carried out for unrelated reasons. Nine horses were still in the original ownership without signs of recurrence and the range of follow up times was 3 to 85 months (average 36 months).
Horse 2 returned to eventing but within 7 months had become lame with navicular disease and had clinical and endoscopic signs of recurrence of the haematoma. Euthanasia was performed and a post-mortem examination revealed the lesion to have recurred and grown into the nasopharynx. Horse 19 had a right-sided haematoma and at the time of surgery there was no endoscopic evidence of a left-sided lesion. However, within 13 months leftsided epistaxis occurred associated with a typical lesion on the left side. There was no recurrence of the original right-sided lesion. The left-sided lesion was operated on but a post-operative endoscopic examination 2 months later revealed a small regrowth on this side. This lesion was treated with a YAG laser under endoscopic control and the horse has returned to full exercise although it is too soon to assess the effects of the third operation. It is also possible that Horse 16 had developed a contralateral lesion. Having remained without signs for 12 months after surgery there were 3 episodes of slight left-sided epistaxis and an intermittent nasal discharge over the subsequent 20 months. However, the horse was still in full work and the owner would not permit a follow up endoscopic examination. Discussion The history of unilateral (bilateral) epistaxis, nasal discharge and, in horses with very large lesions, nasal obstruction was consistent with previous descriptions (Cook and Littlewort 1974; Boles 1979; Haynes 1984; Greet 1985; Specht et al. 1990). A characteristic lesion was recognised in the ethmoid region of all horses except Horses 1 and 21. In the latter a typical lesion was noted in the middle nasal meatus but in the former only turbinate enlargement with a mucopurulent discharge from the sinus ostium was recognised. Lesions originating in the maxillary sinuses have been reported previously (Cook and Littlewort 1974; Sullivan et a / . 1984; Gibbs and Lane 1987). Radiographic examination was a useful aid in assessing the size and extent of the lesion (Boles 1979; Gibbs and Lane 1987) but in this series a provisional diagnosis could be made in 22 horses on endoscopic grounds alone. Radical surgical excision as described in all previous reports (Cook and Littlewort 1974; Bonfig 1989; Specht et al. 1990) was found to be an effective means of removing the lesion although always associated with moderate or severe haemorrhage. No attempt was made to use cryosurgery as reported previously (Cook and Littlewort 1974; Specht et a/. 1990). Suction was found invaluable although visibility was always difficult because of limited access. Blind gentle curettage using gauze swabs was used to eliminate smaller remnants after the bulk of the lesion had been removed. One horse died from encephalitis presumably as a result of this procedure and surgeons must be aware of this potential complication. Temporary carotid ligation has been advocated to reduce intraoperative haemorrhage during nasal surgery (Wyn-Jones et a/. 1986) but was not found to be effective in the one horse for which it was used and it added significantly to surgical time. Although a source of cross-matched blood was available for each horse it was not found to be necessary. By contrast Specht et a / . (1990) administered cross-matched blood to 8 out of 9 operated horses. Arterial blood pressure monitoring combined with dobutamine supplementation when necessary and continuous infusion with polyionic fluids were used throughout general anaesthesia to maintain arterial blood pressure within normal limits. Surgical speed was considered invaluable in minimising blood loss. Nasal packing with gauze bandage was effective in reducing post-operative haemorrhage although in most horses a degree of haemorrhage persisted after packing. In one horse this was so severe that sinus packing had to be repeated. Nasal tubes improved airflow after removal of the endotracheal tube and therefore produced a smoother recovery from anaesthesia. A tracheostomy tube was used in 2 horses with a bilateral lesion and
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is recommended for bilateral cases where nasal packing would otherwise produce post-operative dyspnoea. Removal of the packing between the 2nd and 4th post-operative day was associated with significant haemorrhage in only one horse in which the wound had to be repacked under a second general anaesthetic. In this horse the circulating red cell count was 2 x 1012/litreand the packed cell volume was 9%. Other than the horse which died, post-operative complications were relatively minor but included facial wound dehiscence, suture periostitis and facial bone sequestration. None of these caused a persistent problem. A post-operative nasal discharge was present for several weeks in most horses but in 2 cases it persisted for 1 year. Fungal plaques were found in 3 horses and presumed to be opportunistic infections (Greet 1981). The lesion definitely recurred in 1 horse on the operated side and probably recurred in 2 others on the contralateral side, However, in 18 other horses there was no evidence of regrowth. Unfortunately 6 horses were lost to follow up but if 12 months is used to the minimum useful follow-up period 13 horses were clear at this stage. Nine horses were clear at 24 and 36 months post-operatively. Cook and Littlewort (1974) reported on 13 cases of which there was a recurrence in 5 and Specht et a/. (1990) reported on 9 cases of which 4 suffered a recurrence of the lesion. Bonfig (1989) using a similar surgical technique reported no recurrence in 10 out of 13 cases followed up over a 6-84-month postoperative period. Assessing accurate success rates following surgical excision of an ethmoidal haematoma is very difficult for various reasons; principally because horses may be sold because of owner concern about the recurrence of the lesion. There are few published guidelines about the length of time after which recurrence of the lesion is unlikely. From the present series the success rate following radical excision appears to be 78%, similar to the results of Bonfig (1989). However, all surveys of this nature must be qualified by the time scale of follow up. In all cases the histological appearance of the lesion was as
reported by Platt (1975) but the aetiology remains obscure. Although the lesion acts in a neoplastic manner there is little histological evidence to support this aetiology.
Acknowledgements I am grateful to all the veterinary surgeons for referring the cases, completing questionnaires and providing follow-up information and in particular to Ian Wright and the Cambridge Veterinary School to whom Horse 13 was referred; to my colleagues at Beaufort Cottage Stables and the Animal Health Trust who administered general anaesthesia to the horses and generally helped with the cases; and to Niamh Nash for typing the manuscript.
References Boles, C. (1979) Abnormalities of the upper respiratory tract. Vet. Clin. N. Am. LorgeAnimal Pracr. 1.89-111. Bonfig. H. (1989) Diagnose und Therapie des progressiven Hamatoms der Siebbeinregion - dargestellt an 13 Klinischen Fallen. Pferdeheilkunde 5.71-79. Cwk. W.R. and Littlewort, M.C.G. (1974) Progressive haematoma of the ethmoid region in the horse. Equine vcr. J. 6, 101-108. Gibbs. C. and Lane, J.G. (1987) Radiographic examination of the facial nasal and paranasal sinus regions of the horse. 11 Radiological findings. Equine ver. J. 19. 474-482. Greet, T.R.C. (1981) Nasal aspergillosis in three horses. Vet.Rec. 109,487-489. Greet, T.R.C. (1985) The respiratory tract. In: Equine Surgery and Medicine. Ed: J. Hickman. Academic Press, London. p 266. Haynes. P.F. (1984) Surgery of the equine respiratory tract. In: Practice of .!.urge Animal Surgery. Ed: P.B. Jennings. W.B. Saunders Co.. Philadelphia p 404. Platt (1975) Nasal polyps of the horse. J. Pathol. 115,5 1-55. Specht. T.E., Colahan, P.T., Nixon. A.J., Brown, M.P., Turner, T.A., Peyton, L.C. and Schneider, R.K. (1990) Ethmoidal haematoma in nine horses. J. Am. vet. med. Ass. 197.613-616. Sullivan. M., Burrell. M.H. and McCandlish. I.A.P. (1984) Progressive haematoma of the maxillary sinus. Vet. Rec. 114. 191-192. Wyn-Jones. G.. Jones, R.S. and Church, S. (1986)Temporary bilateral carotid artery occlusion as an aid to nasal surgery in the horse Equine vet. J. 18. 125-128.
Received for puhlication: 13.1.92 Accepted: 23.4.92
FIELDINVESTIGATION OF GRASS SICKNESS An epidemiological study of grass sickness has recently been launched. As a questionnaire based case control study, it aims to determine more accurately the geographical distribution of the disease in Great Britain and to quantify the importance of different predisposing factors.
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If veterinary surgeons diagnose grass sickness in an animal under their care, please could they or the owner contact eitherJames Wood (Animal Health Trust, 0638-66111 1) or Kevin Scott (Equine Grass Sickness Fund 031-664-3262),Owners will then, in confldence, be sent simple questionnaires for completion.
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