Nasal and Facial Reconstruction in a Dog Following Severe Trauma
Successful reconstruction of the nasomaxillary region requires closure of oronasal communication and maintenance of a patent upper airway. A dog with traumatic amputation of the nasomaxillary region was presented for reconstructive surgery. Staged surgical procedures were performed with the goal of closing the oronasal fistula, reapposing facial tissues, forming a granulation bed in each nasal passage, and harvesting and placing mucosal grafts in the nasal passages. A novel technique for developing a granulation tissue bed for mucosal grafts using silicone rubber tubing was employed. The end result of the reconstructive surgeries was a relatively cosmetic appearance with patent nasal openings.
Introduction
Resection of the nasal planum and premaxilla has been described for tumor excision.1 The soft tissues of the nasomaxillary region are incised, and the nasal cartilages are incised to the level of the palatal region of the maxillary bone. The palatal and maxillary bone is then cut with an oscillating saw. For closure, the soft tissues of the lip are reconstructed, and the nasal planum is closed with a simple continuous purse-string suture.1 The mucosal lining of the nasal cavities is left intact, and, thus, the nasal opening remains patent. Removal or retraction of mucosal lining, whether by trauma or aggressive tumor excision, can cause wound healing problems. It promotes fibrous connective tissue formation and stenosis. Retraction of mucosa and occlusion with fibrous connective tissue have been well documented in urethral healing.2 In the case presented here, traumatic amputation of the nasomaxillary region resulted in a loss of nasal cavity mucosa. Surgical repair included creating a healthy granulation bed to line the nasal cavity and providing a mucosal lining with sublingual grafts.
Case Report
A 3-year-old, intact male Labrador retriever was presented with a history of severe facial trauma resulting from placing his nasomaxillary area in the rotating tail rotor blades of a helicopter during playful investigation of the rotor as the engine idled. The nasomaxillary region was traumatically, yet relatively cleanly, amputated approximately 4 cm rostral to the medial canthi of the eyes, with the amputated nasomaxillary segment attached to the face by a small segment of soft tissue. The dog was taken to a local veterinarian immediately following the trauma. After administering systemic antibiotics and anesthetizing the dog, the area was cleaned and debrided to include removal of the pendulous nasomaxillary area. The dog was referred to the Small Animal Surgery Section of the Department of Clinical Sciences at Auburn University’s College of Veterinary Medicine.
Physical examination revealed an alert, responsive dog in good health, with the exception of the aforementioned absence of the nasomaxillary area [Figures 1A, 1B]. Hematological and serum chemical values were within reference ranges, with the exception of an elevated serum alkaline phosphatase, a slightly elevated glucose, and a slightly elevated total bilirubin. There was also a moderate number of Dirofilaria immitis found on Knott’s test. Radiographic examination of the thorax revealed slight cardiac enlargement.
Upon admission, the dog was continued on systemic antibiotics of cefazolina (22 mg/kg body weight, intravenously [IV] q 8 hours). Preanesthetic medication of acepromazineb (0.05 mg/kg body weight, intramuscularly [IM]), atropine sulfatec (0.04 mg/kg body weight, IM), and butorphanol tartrated (0.4 mg/kg body weight, IM) were administered. Anesthesia was induced with thiopental sodiume (15 mg/kg body weight, IV). Following endotracheal intubation, anesthesia was maintained with isofluranef (baseline of 2% in 30 mL/kg body weight per minute of oxygen). Lactated Ringer’s solution was administered during surgery (11 mL/kg body weight per hour, IV).
The facial area was clipped and prepared for aseptic surgery from the level of the rostral bases of the pinnae forward. After positioning the dog in sternal recumbency with the head slightly elevated, quarter drapes were placed around the area that had been prepared for surgery. The rostral-most drape was placed over the tongue and mandible.
The area of the wound was covered with devitalized tissue and scabs. These were debrided, and the oral cavity was flushed with a 0.05% solution of chlorhexidine gluconate.g Examination revealed a soft-tissue flap on each side of the face. These flaps were composed of full-thickness segments of the lips distally and the facial soft tissues proximally. The flap on the right side of the face was longer than the one on the left [Figures 2A, 2B]. It was suspected that the rotor blade hit the left side of the face first, cutting the soft tissue against the bone. The bones of the area then broke. Thus, there was no solid structure on the right side of the face for soft tissues to be cut against, and they were stretched considerably before they were cut.
There was a triangular piece of maxilla buried in and attached to the soft tissue in the flap on the left side of the face. The left upper second premolar was fractured below the gum line.
The order of reconstructive procedures was planned. The fragment of maxilla would be replaced, and the fractured premolar would be extracted. For soft-tissue reconstruction, first the buccal tissues on both sides of the face would be advanced rostrally to become the new labial tissues. The proximal edge of the flaps would be affixed to the rostral edge of the remaining palatine process of the maxilla. Second, the edges of the labial portions of the flaps would be apposed. Third, the facial soft tissues around the nasal openings would be apposed. Fourth, new nasal openings would be created [Figure 3].
Using a power drill and 0.45-mm Kirschner wire (K wire), two holes were drilled in the maxilla at the edge of the defect. Matching holes were drilled in the fractured segment of bone, and the segment was secured to the maxilla using a hemicerclage-wiring technique with 20-gauge orthopedic wire.
Using the same drill and K wire, four equally spaced holes were drilled across the front edge of the remaining palatine processes of the maxilla, two on either side of the midline. The holes went through the nasal mucosa, palatine process of the maxilla, and the oral mucosa. Starting at the most lateral hole on the left side, a curved cutting needle with 2-0 swaged monofilament nylonh was passed from the oral side to the nasal side through the hole. The left flap was then placed across the front of the palatine process of the maxilla, and the needle was passed from submucosal to the mucosal side of the flap. The same procedure was repeated on the remaining three holes, with the labial portion of the left flap being affixed to the left side of the palatine process of the maxilla, and the labial portion of the right flap being affixed to the right side of the palatine process of the maxilla. Simple interrupted sutures of 2-0 polyglactin 910i were then placed between the four nylon sutures from the oral side. This further affixed the flaps to the edge of the palatine process of the maxillae and provided more accurate apposition of the labial mucosal edge to the oral mucosa on the palatine process of the maxillae. All suture knots were in the oral cavity, which would allow for removal after tissue healing. Communication between the oral and nasal cavities was now eliminated [Figures 4, 5].
The rostral soft tissues of the left and right flaps were then apposed to create a new labial margin. Tissue layers were closed from deep to superficial with simple interrupted sutures of 2-0 polyglactin 910. Because of the thickness of the tissues, three layers of sutures were necessary to appose the tissues. Suturing was started distally and progressed proximally until half of the defect was closed. The skin edges of the flaps were apposed with simple interrupted sutures of 5-0 stainless steelj [Figure 6]. At this time, the fractured second premolar was extracted.
Because of the extensive trauma to the area, no nasal mucosa could be identified to suture to the remaining skin edges of the flaps for creation of a mucocutaneous junction and thus a nasal opening. The first step in creating two nasal openings was performed.
A 4-cm length of silicone rubber tubingk with an external diameter of approximately 10 mm was inserted on either side of the nasal septum caudally into intact nasal cavity. The length of the tube was such that it would traverse the area of traumatized tissue into normal nasal cavity [Figure 6]. Simple interrupted sutures of 2-0 polyglactin 910 were used to finish closing the soft tissues of the flaps snugly against and between the tubes. Skin from the proximal aspect of the defect was brought distally and sutured to the skin on the proximal aspect of the right flap; thus, skin was pulled between the two tubes to separate them and create two nasal openings [Figures 6 (insets A, B), 7]. The rostral end of each tube was sutured to the skin with four simple interrupted sutures of 2-0 monofilament nylon [Figures 6 (inset B), 7].
The purpose of the tubes was to provide forms around which granulation tissue would develop from the traumatized soft tissue of the flaps. The tubular granulation tissue structure would provide a vascular bed for placement of mucosal graft linings.
Postoperative therapy and care consisted of maintenance crystalloid fluids for 24 hours and cefazolin (22 mg/kg body weight, IV q 8 hours for 24 hours). Analgesia was provided with buprenorphinel (0.015 mg/kg body weight, IV q 6 hours). Acepromazine (0.05 mg/kg body weight, IV q 6 hours) was used as needed for tranquilization. Cefazolin was discontinued 24 hours postoperatively, and cephalexin (22 mg/kg body weight, per os [PO] q 8 hours) was given for 14 days. During the first 24 hours postoperatively, the patient allowed the nasal area to be gently cleansed with gauze sponges, moistened with 0.05% chlorhexidine solution, every 6 hours to prevent occlusion. Thereafter, the patient’s tolerance waned, and the nasal area was cleansed once daily using sedation with medetomidinem (20 μg/kg body weight, IV) followed by reversal with an equal volume of IM atipamezole. On the third postoperative day, a transdermal fentanyl patchn (5 μg/kg) was placed to permit discontinuation of injectable analgesics by 24 hours after placement of the patch. The nasal tubes remained patent. An Elizabethan collar was placed to prevent trauma to or dislodgment of the nasal tubes. The dog ate well postoperatively and remained in the hospital until the completion of all surgical procedures.
Ten days after the first surgical procedure, the skin incisions had healed well, and the tubes had remained in place to serve as scaffolds for granulation tissue to form around. At this time, preanesthetic medication that was used for the first surgery was used for the second surgery, except no butorphanol tartrate was given preoperatively, and fentanyl patches (175 μg) had been applied transdermally. Anesthesia was induced and maintained in the same manner as with the first surgical procedure. Lactated Ringer’s solution was administered (11 mL/kg body weight, IV) during surgery.
The dog was placed in sternal recumbency on the surgery table, with the head slightly elevated. Quarter drapes were placed as in the first surgery, except the drape that was placed over the tongue before was placed beneath the mandible for this surgery. The sutures holding the two silicone rubber tubes in place were removed, and the tubes were easily pulled from their positions. Healthy granulation tissue tubes had formed around the silicone tubes. The head was turned slightly to the right, and the mandible was retracted ventrally while an assistant surgeon retracted the tongue dorsally. This exposed the left sublingual area. A surgical skin markero was used to draw a 5 × 3-cm rectangle on the sublingual mucosa, with the long axis of the rectangle parallel to the long axis of the tongue. Care was taken not to design the mucosal grafts over the sublingual salivary duct. A no. 15 scalpel blade was used to incise the rectangle, and traction sutures of 3-0 polyglactin 910 were placed at each corner of the rectangle. Using Metzenbaum scissors, the mucosal graft was dissected away from the genioglossus muscle progressing from rostral to caudal while placing caudal traction on the two rostral-most stay sutures [Figure 8].
After removal of the graft, it was sutured with the submucosal side out around one of the silicone tubes that had been removed from the nasal area using simple interrupted 4-0 polyglactin 910 sutures [Figure 9A]. Four removable traction sutures of 3-0 polyglactin 910 were placed in the ends of the mucosal graft. These were placed so the graft could be held under tension to keep it smoothly stretched on the silicone rubber tube while it was reinserted into the granulation tissue tube that had formed around it during the previous 10 days. Two doubled sutures were placed in one end of the mucosal graft 180° apart. Similar sutures were placed in the other end of the graft [Figure 9B]. The sutures in the end of the graft that would be placed back in the nasal cavity were threaded back through the end of the tube to which they were closest, and they came out the other end of the tube. Sutures in the other end of the graft were not threaded through the tube [Figure 9C].
The tube with the graft around it was then inserted into the right nasal passage. The end of the tube that had the two stay sutures threaded into it was inserted. With gentle pressure, the silicone tube and graft were pushed into the granulation tissue tube. As the tube was pushed in, traction was placed on all four traction sutures to keep the graft smoothly stretched on the tube during insertion [Figure 9D]. When the silicone tube was inserted until its rostral end and the graft edge were flush with the end of the granulation tissue tube, three simple interrupted 3-0 nylon sutures were used to suture the edge of the mucosal graft to the skin at the edge of the granulation tissue tube. Three more like sutures were placed between these sutures. These went through the silicone tubing, the graft, and the adjacent skin. Thus, a new mucocutaneous junction was created while also anchoring the rostral end of the silicone tubing [Figure 9 (inset E)]. After suturing, the two rostral-most traction sutures were removed by traction on one of their ends. The two caudal-most traction sutures emerging from the lumen of the silicone tube were removed in like manner. The end result was a mucosal graft lining the previously formed granulation tissue tube, with the silicone rubber tube acting as a stent to hold it against the granulation tissue while it revascularized and healed in place.
The sublingual graft donor site was sutured with 3-0 polyglactin 910 suture material in a Ford interlocking pattern.
The dog’s head was then turned to the left, and the same grafting procedure was repeated on the left nasal passage using a left sublingual mucosal graft.
At the junction of the labial portions of the left and right flaps, a slight suture line separation had occurred. The wound edges were debrided and closed in two layers, with two 3-0 simple interrupted sutures of polyglactin 910 in the deep tissues and four 4-0 simple interrupted stainless steel sutures in the skin. Thus, a smooth labial edge was reestablished across the front of the face.
The area where the labial mucosa had been sutured to the oral mucosa along the remaining front edge of the palatine processes of the maxillae was examined. There had been some dehiscence of the suture line. The remaining nylon sutures were removed, and at areas where there had been disruption of the suture line, the wound edges were debrided with a no. 15 scalpel blade and were resutured with vertical mattress sutures of 2-0 polyglactin 910.
Postoperative therapy and care consisted of crystalloid fluids for 24 hours postoperatively and maintenance of a transdermal fentanyl patch (5 μg/kg body weight). Acepromazine was given (0.05 mg/kg body weight, IV q 6 hours). The patient began regurgitating 3 days postoperatively. A sucralfate slurry (1 gram sucralfate mixed with water) was given orally every 8 hours for 5 days to protect the esophageal mucosa. The fentanyl patch was removed, and the episodes of regurgitation stopped. The nostrils were gently cleansed with a 0.05% solution of chlorhexidine, once daily, with the use of medetomidine sedation (20 μg/kg body weight, IV) and an equal volume of atipamezole given IM for reversal.
Seven days after the second surgical procedure, the preanesthetic medication and anesthetic induction and maintenance were the same as for the first surgery. The dog was placed in sternal recumbency, and the sutures in the rostral edge of the graft and the silicone tubing were removed. The silicone tubes were easily removed, leaving two circular openings lined with mucosa and a well-healed mucocutaneous junction [Figure 10]. There was no cartilaginous support to these openings, and it was suspected they would tend to collapse. To help prevent this, an attempt was made to enlarge the openings to the point of over-correction. Crescent-shaped segments of skin were removed both dorsal and ventral to the new openings. The curvature of the crescents matched the curvature of the openings, with the inner curve of the crescents approximately 3 mm from the mucocutaneous junction and the width of the crescents 3 mm at the widest point [Figure 11A]. Following removal of the skin crescents, the skin edges were sutured with simple interrupted sutures of 3-0 polypropylene.1 This further opened the nasal opening and everted the mucocutaneous junction [Figure 11B].
The area of repair of the slight disruption between the two labial flaps had healed well, and the sutures were removed. Likewise, the area of mucosal repair at the rostral aspect of the remaining palatine processes of the maxillae was well healed with no oronasal fistula present.
Postoperative therapy and care consisted of buprenorphine (0.015 mg/kg body weight, IV) and acepromazine (0.03 mg/kg body weight, IV q 6 hours) for 48 hours. The nostrils remained free of debris and were not cleansed.
The end result of the salvage/reconstructive surgery was a relatively cosmetic appearance. However, the dog appeared prognathic with somewhat of a bulldog appearance [Figures 12A, 12B].
As the new nasal openings healed, there was collapse of the soft tissues around the openings. However, with the mucosal grafts in place, the openings remained patent. No large volumes of air could pass through the openings, and the dog was primarily a mouth breather. However, openings remained patent to allow the drainage of nasal secretions and have the appearance of two nasal openings. The dog was doing well at the time of dismissal from the hospital. The owner was offered the option of a final surgical procedure, whereby subdermal supports of silicone rubber rings or autogenous hyaline cartilage from the xiphoid cartilage would be placed around the nasal openings. These could potentially provide support to keep the openings wide. However, the owner did not choose to have this surgery performed. At 2 years after surgery, the dog is functioning well.
Discussion
Three general principles of facial reconstructive surgery have been stated.3 All three, or modifications thereof, were used in the salvage/reconstruction procedures used on this dog.
First, soft tissues are moved from caudal to rostral for reconstruction. This principle was used in moving the flaps from each side of the face rostrally to reconstruct the facial defect.
Second, soft tissues can be wired back on bone. A modification of this principle was used, in that simple interrupted nylon sutures were used as foundational sutures to affix labial tissue to the remaining rostral edge of the palatine processes of the maxillae. Although nylon was used in this case, orthopedic wire can be used and provides good knot security.
Creating a new mucocutaneous junction following planectomy to remove neoplasms of the nasal planum has been described.4 It involves suturing the mucosa lining the nasal cavity to adjacent skin edges. In the case presented here, the trauma associated with the injury severely damaged the nasal mucosa such that there were no identifiable edges for creating mucocutaneous junctions in this way. Thus, the third principle of using mucosal grafts was applied.
Mucosal grafts were used to reconstruct a lining in the granulation tissue tubes that were prepared to salvage nasal openings. Mucosal grafts have been taken from the upper lip to line the inside of a skin flap for eyelid reconstruction.5 Sublingual mucosal grafts have also been described for lining preputial reconstruction skin flaps.6 It was discovered that sublingual mucosal grafts should be designed as far caudal as possible on the tongue. The mucosa separates from the underlying tissue more easily in this area; whereas, mucosa on the more cranial aspect of the tongue is closely adhered to the genioglossus muscle. This makes graft elevation more difficult, and it was necessary to trim musculature off of the graft after harvesting it to get a relatively thin graft.
A novel technique for developing a granulation tissue bed for the grafts using silicone rubber tubing was described. In addition, a unique procedure for applying the grafts to assure smooth application and maintenance of graft-bed contact was described using traction sutures and silicone rubber tubing. Based on experience during this procedure, it is believed that 3-0 monofilament suture material will work better for the traction sutures to keep the graft smooth on the silicone tube as it is inserted. The monofilament sutures would easily slide through the tissues when being pulled out. There was friction between the mucosa and suture when pulling the polyglactin 910 traction sutures out.
It was theorized that thin rings of silicone rubber or autogenous cartilage from the xiphoid cartilage could be placed subdermally around the openings to give support to the area and maintain the openings. However, this was not performed and is speculative.
Conclusion
This manuscript describes utilizing the three general principles of 1) moving soft tissue from caudal to rostral, 2) suturing soft tissue back on bone, and 3) using mucosal grafts, along with imagination, the tissues available, and novel techniques for forming graft beds and applying nasal mucosal grafts.
Cefazolin; G.C. Harford, Syracuse, NY
Acepromazine; Boehringer Ingelheim, St. Louis, MO
Atropine sulfate; Gensia. Sicor. Pharmaceuticals, Irvine, CA
Torbugesic; Fort Dodge Animal Health, Fort Dodge, IA
Thiopental; Abbott Laboratories, North Chicago, IL
Isoflo; Abbott Laboratories, North Chicago, IL
Chlorhexiderm disinfectant; DVM Pharmaceuticals, Inc., Miami, FL
Ethilon; Ethicon, Inc., Somerville, NJ
Vicryl; Ethicon, Inc., Somerville, NY
Monofilament B and Ss stainless steel; Ethicon, Inc., Somerville, NJ
Silastic rubber tubing; Fisher Scientific, Swanee, GA
Buprenex; Reckett and Colman Pharmaceuticals, Richmond, VA
Medetomidine and atipamezole; Pfizer Animal Health, New York, NY
Duragesic; Alza Corpl, Mountain View, CA
Vismark surgical skin marker – Viscot; Viscot Industries, Inc., East Hanover, NJ
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Citation: Journal of the American Animal Hospital Association 39, 4; 10.5326/0390407
Results of traumatic (from a helicopter rotor) nasomaxillary amputation of a 3-year-old Labrador retriever. Frontal view (A); lateral view (B).
Photograph (A) and diagram (B) of the dorsal view of the nasomaxillary area in the dog from Figure 1 prepared for the first surgical procedure, showing bilateral flaps composed of facial soft tissues (FST), full-thickness labial tissue (Lab.), palatine process of maxilla (PPM), and nasal cavities (NC).
Diagram of the planned sequence for salvage/reconstructive surgery for the dog from Figure 1. (1) Apposing the cut edge of labial mucosa to mucosa on rostral edge of palatine process of the maxilla (closing oronasal communication); (2) apposing ends of labial portions of flaps; (3) apposing facial soft-tissue portions of flaps; (4) remaking nasal cavities.
Apposing the cut edge of labial mucosa to mucosa on rostral edge of palatine process of maxilla. (1) Proposed site of drilling; (2) hole drilled through palatine process of maxilla; (3) nylon suture passed up through hole and down through the cut edge of labium, from the submucosal to mucosal side; (4) nylon suture tied with knot in the oral cavity.
(A) Dorsal (nasal side) view of oronasal communication closure. All four nylon sutures were tied with knots in the oral cavity. Polyglactin 910 sutures will be placed intermittently between nylon sutures (arrows). Nasal cavity (NC). Labial submucosa (Lab. Smu.). (B) Ventral (oral side) view of oronasal communication closure. Placing polyglactin 910 sutures between nylon sutures. Labial mucosa (Lab. M.).
Closure of labial edges and soft-tissue portions of flaps. Silicone rubber tubes have been placed in nasal cavities. Moving and suturing skin between the tubes (insets A and B).
Diagram (A) and photograph (B) of final closure for creating nasal openings.
Diagram demonstrating the technique of harvesting a mucosal graft from under the tongue.
(A) Suturing mucosal graft around silicone rubber tube with the submucosal side out. (B) Placing two traction sutures in the rostral end and the nasal cavity end of the graft. (C) Threading the traction sutures from the nasal cavity end of the graft back through tube lumen. (D) Inserting the tube and graft into the right nasal opening while exerting traction on the sutures. The traction sutures keep the graft smooth on the tube. (inset E) Three interrupted sutures hold the tube, graft, and skin edge; and three interrupted sutures hold the graft and skin edge.
Photograph of nasal opening with healed mucosal graft linings.
(A) Removing crescents of skin adjacent to the nasal openings. (B) Closing the crescent defects to enlarge the nasal openings.
