Outcome and complication rate of nasal planectomy reconstructed with direct mucocutaneous apposition

Abstract

Nasal planectomy is recommended in cases of squamous cell carcinoma of the nasal planum in dogs and can be curative if excision is complete. Due to the noticeable alteration in appearance inherent in nasal planectomy, several techniques are described for reconstruction. The goal of this study is to report the complication rate and owner satisfaction following nasal planectomy with repair by direct mucocutaneous apposition compared to other reported reconstruction techniques meant to be more cosmetic. Eleven dogs were identified that underwent nasal planectomy with reconstruction via mucocutaneous apposition. Complications were noted in 8/11 dogs: all minor. All dogs underwent CT preoperatively for surgical planning. Complete excision was noted in 10/11 cases. Results suggest that direct mucocutaneous apposition is a viable surgical option for reconstruction following nasal planectomy with favorable major complication rates and owner satisfaction. In addition, direct mucocutaneous apposition for closure following nasal planectomy should be considered, especially in cases in which bone is not resected, because of low complication rates and reasonable cosmetic outcome.

Introduction

The most diagnosed tumor of the canine nasal planum is squamous cell carcinoma (1) although other tumor types such as fibrosarcoma, melanoma, mast cell tumor, and osteosarcoma have been reported (2,3). In the case of locally invasive tumors, surgical resection is recommended and can be curative if excision is complete (4,5). Depending on the caudal extent of the tumor, surgical resection may require only nasal planectomy or may necessitate resection of the premaxilla (incisivectomy) as well (2). The degree of surgical resection necessary has been determined in the past by palpation and rhinoscopy (6) and, in more recent years, with preoperative computed tomography (CT) (7). Although complete resection can be considered curative for locally invasive tumors such as squamous cell carcinoma, preoperative planning is critical to obtain complete excision (5,6).

Nasal planectomy has a drastic effect on cosmesis that may be difficult for owners to accept. That, and the difficulty of achieving closure of the surgery site while leaving a patent nasal aperture, has led to the description of several different techniques for reconstruction following nasal planectomy. One reported technique involves apposition of the skin of the lips on the rostral midline and reduction of the diameter of the nasal skin opening to the diameter of the nasal passages with a purse string suture. In this technique, the skin is not sutured to the mucosa and healing is by second intention (2,8). A second technique, an improvement on the first, involves mucocutaneous apposition in which the skin is sutured directly to the turbinate mucosa allowing for primary healing and decreasing granulation tissue formation (6). More recently, attempts have been made to improve the cosmesis of the repair with a third technique using bilateral buccal mucocutaneous rotation-advancement flaps to create a non-haired, pigmented protrusion to replace the nasal planum and protect nasal turbinates (4).

Complications for purse string closure have been reported to be common, although most resolved without treatment (2,9); whereas no major complications were reported with mucocutaneous apposition (6). A recent article by Dickerson et al (7) evaluating the outcome and owner satisfaction using this third, more cosmetic reconstruction technique, reported a high complication rate of 73% with 9/26 dogs requiring revision surgery and 1 not surviving to discharge. However, despite high complications rates, owner satisfaction was high with 8/11 owners surveyed stating that, knowing how their dog recovered, they would consider surgery again in a similar situation (7).

The goal of this study was to report the complication rate and owner satisfaction of rostral nasal reconstruction using direct mucocutaneous apposition following nasal planectomy with and without incisivectomy.

Materials and methods

Medical records completed between 2014 and 2019 from a single referral practice were searched to identify dogs undergoing nasal planectomy. Information collected included age, weight, sex, breed, clinical signs, tumor type, the presence or absence of metastasis at the time of surgery, preoperative imaging, the extent of resection (soft tissue alone versus incisivectomy), surgical margin results, perioperative complications, and cause of death where applicable.

Referring veterinarians were contacted by telephone for information including date of last follow-up and if the dog was alive or deceased. Owners were contacted by telephone and their responses to questions regarding their dog’s outcome were recorded. Questions were designed to evaluate the quality of life of the patient following healing in comparison to before surgery, as well as complications, owner satisfaction with appearance, and if they would consider surgery again in light of their experiences. Owners were also asked about survival time following surgery and cause of death or reason for euthanasia as applicable.

Overall and major postoperative complications occurring between the procedure and documented healing of the surgery site as well as between healing and death or end of the study period were evaluated and categorized as major or minor. Major complications were defined as those requiring surgical intervention or those resulting in death. Minor complications were defined as those that did not require a second surgical procedure such as minor focal dehiscence, granulation tissue at the surgery site, or increased sneezing and nasal discharge.

Computed tomography of the head was performed in all cases for preoperative planning and to evaluate regional lymph nodes. Additional scans following injection of intravenous contrast medium were completed at the discretion of the consulting radiologist. For each case, the attending surgeon evaluated the images for surgical planning with the goal of maintaining 1-cm margins from the caudal extent of the mass. If incisivectomy was required to achieve the desired margins, the extent of planned excision was adjusted caudally to the nearest interdental space. Time between head CT and surgery was noted for all dogs.

In all cases, the repair technique used was similar to that described by Kirpensteijn et al (2) with the addition of mucocutaneous apposition as described in Lacelles et al (6), rather than purse string for reconstruction of the nasal aperture.

Complication rates in this study were compared with those of a recent study using statistical analysis to evaluate the method of repair reported to be more cosmetic (7). Fisher’s exact test was used to test for a difference in rate of complications between the 2 studies.

Results

Eleven dogs were identified that underwent nasal planectomy with reconstruction by mucocutaneous apposition (Table 1). Of the total, 6 (54.5%) underwent nasal planectomy alone and 5 (45.5%) underwent nasal planectomy with incisivectomy. Median age at time of surgery was 11 y (mean: 10 y; range: 8 to 13 y) and median weight was 38.3 kg (mean: 43.8 kg; range: 27.2 to 89.4 kg). Most dogs were castrated males (n = 8) and the remaining 3 were spayed females (n = 2) and an intact male (n = 1). The Labrador retriever was the most common breed represented (n = 6), followed by golden retriever (n = 2), old English mastiff (n = 2), and Australian sheepdog (n = 1). Ten of the 11 dogs were diagnosed with squamous cell carcinoma and 1 was diagnosed with amelanotic melanoma. Only 1 dog had evidence of probable metastasis at the time of surgery in the form of 2 small pulmonary nodules noted on thoracic CT. A preoperative CT of the head was performed in all cases. In 5/11 cases (45%) this was performed immediately before surgery and for the remaining 6 cases, the median time between CT and surgery was 7.5 d (mean: 7.7 d; range: 1 to 14 d). Incisivectomy was performed in 5/11 dogs, and, in all cases, reconstruction of the nasal aperture was with mucocutaneous apposition (Figure 1). Excision was noted to be complete through histopathological findings in 10/11 (90.9%) of cases, although margins were narrow in 1 case (1-mm caudal margins). Vascular invasion was noted in 3 cases, 1 of which was the patient diagnosed with malignant melanoma. Of the remaining 8 cases, 4 were noted to have no vascular invasion and the histopathology reports of the final 4 made no mention of presence or absence of vascular invasion.

Table 1.

Demographic characteristics of 11 client-owned dogs treated with nasal planectomy with or without incisivectomy for neoplasia of the nasal planum.

Signalment	Diagnosis	Incisivectomy	Excision complete	Vascular invasion	Complications	Survival time	Cause of death/reason for euthanasia (if given)
Labrador retriever, MC, 11 y	SCC	Yes	No	No	None	Euthanized at 215 d	Mass regrowth
Labrador retriever, MC, 11 y	SCC	No	Yes	Yes	Minor, increased sneezing and nasal discharge.	Euthanized at 258 d	Trouble walking/rising due to decreased quality of life.
Australian shepherd, MC, 12 y	SCC	No	Yes	No	Minor, small dehiscence. Resolved without intervention.	Alive at 67 d	N/A
Labrador retriever, MC, 9 y	SCC	Yes	Yes	Not reported	Minor, increased sneezing, small dehiscence. Healed with staple placement.	Euthanized at 602 d	Tumor at left sacroiliac joint.
Mastiff, MI, 9 y	SCC	No	Yes	Yes	None	Euthanized at 496 d	Osseous lesion, left hindlimb — suspect neoplasia.
Golden retriever, MC, 11 y	SCC	Yes	Yes, narrow caudally	No	Minor, granulation at lip margin.	Euthanized at 522 d	Gradual decline, hind limb weakness, seizure activity.
Labrador retriever, MC, 11 y	SCC	Yes	Yes	Not reported	Minor, granulation at lip margin.	Euthanized at 93 d	Tumor extending through cribriform plate, suspect regrowth of SCC.
Labrador retriever, FS, 13 y	Melanoma	No	Yes	Yes	None	Euthanized at 65 d	Inappetence, lethargy.
Golden retriever, FS, 8 y	SCC	No	Yes	Not reported	Minor, increased sneezing.	Euthanized at 1270 d	Severe non-ambulatory paraparesis and incontinence.
Labrador retriever, MC, 8 y	SCC	No	Yes	No	Minor, increased nasal discharge.	Alive at 1114 d	N/A
Old English mastiff, MC, 8 y	SCC	Yes	Yes	Not reported	Minor, increased sneezing.	Died at home at 445 d	Unknown, possible regrowth noted.

MC — Male castrated; MI — Male intact; FS — Female spayed; y — Years; SCC — Squamous cell carcinoma; N/A — Not applicable.

Figure 1.

Intraoperative images of mucocutaneous apposition for closure following nasal planectomy and incisivectomy just following skin incision (A), after skin incision, after nasal planectomy and incisivectomy (B), following closure of buccal and gingival tissues (C), and after completion of closure (D).

Post-operative complications were noted in 8/11 cases (72.7%); all were minor. Complications included increased sneezing (4) and increased nasal discharge (2) as well as complications associated with the rostral aspect of the skin closure such as a small area of granulation tissue (2) and a small dehiscence (2), with some patients experiencing more than one complication (Table 1). Of the 2 dogs that experienced a small dehiscence, both defects were under 1 cm in length and only 1 required minor intervention in the form of a placement of a single skin staple. No major complications were noted within the study group. When compared to a recent study by Dickerson et al (7) evaluating a reportedly more cosmetic method of reconstruction following nasal planectomy, overall complication rate did not differ significantly between studies. However, the rate of major complications was significantly lower in this study than in the Dickerson et al (7) study (Fisher’s exact test = 0.018).

Two dogs were alive at the end of the study period, and 9 were deceased. Of the dogs that were alive at the end of the study period, 1 underwent nasal planectomy surgery in the 2 mo leading up to the end of the study period and 1 had survived 1114 d and was still alive at the end of the study period. The estimated mean survival time was 491.2 d ± 145.0 d [standard error (SE)] from the date of surgery and the estimated median survival time was 496.0 ± 217.0 d. Of the 9 dogs that were deceased, 4 died from causes probably related to the tumor including the dog diagnosed with amelanotic melanoma that was euthanized following a decline in quality of life due to suspect metastatic disease 65 d after surgery. Of the other 3, all diagnosed with squamous cell carcinoma, 1 developed a recurrent mass at the surgery site and died at home of natural causes 445 d after surgery. The second was euthanized following diagnosis of a suspected regrowth extending through the cribriform plate, and the third was euthanized following tumor regrowth resulting in an unacceptable quality of life. The remaining 5 dogs that were deceased, all diagnosed with squamous cell carcinoma, were euthanized from causes likely unrelated to the original tumor including, a sublumbar mass causing severe non-ambulatory paraparesis and incontinence, a bone tumor in the left tibia, a left sacroiliac tumor resulting in non-ambulatory paraparesis, a gradual decline followed by sudden onset of seizure activity, and trouble rising and walking resulting in an unacceptable quality of life.

Owners of 9/11 dogs (82%) were reached for follow-up. Six (67%) of these owners were happy with the postoperative appearance of their dogs (Figure 2), 2 (22%) were neutral stating in 1 case that the appearance was “odd,” and 1 (11%) was not happy noting that his dog had a “gaping hole” in his face. When asked if they would pursue surgery again knowing what they know now, 7 (78%) of the owners stated that they would and 2 (22%) stated that they would not. Sneezing was noted by the owners to be increased following surgery in 7 cases (78%), but 4 of these owners noted that the sneezing improved with time to a level comparable to that before surgery. Two owners felt that the sneezing continued to be more frequent and 1 could not recall. Only 4 owners (44%) noted increased nasal discharge following surgery, 2 of which noted improvement to normal levels, 1 that stated levels stayed increased, and 1 that noted it to be only intermittent. Of the 2 patients that had persistent nasal discharge, both were noted to have nasal discharge present before surgery. However, of the 4 patients noted to have increased sneezing, only 1 was noted to have increased sneezing prior to surgery.

Figure 2.

Healed surgery sites after repair with mucocutaneous apposition at 3 y (A), 2 y (B), and 2 weeks (C, D) following surgery.

Discussion

Mucocutaneous apposition is a viable option for reconstruction following nasal planectomy with a major complication rate significantly lower than that reported for repair with bilateral buccal mucocutaneous rotation-advancement flaps. Owner satisfaction was also high with this method of repair.

The overall complication rate for this study was 72.7% (8/11) with a major complication rate of 0%. When compared to the complication rate for reconstruction with bilateral buccal mucocutaneous rotation-advancement flaps described by Dickerson et al (7), the major complication rate of this study was significantly lower. Dickerson et al (7) reported 73% (19/26) of dogs suffered a complication with some suffering multiple. In addition, 35% (10/26) of dogs in that study underwent revision surgery and 1 did not survive to discharge (7). In contrast, all complications herein were minor, and none required additional surgical treatment. A single skin staple was added to close 1 incisional dehiscence in the group of dogs repaired with mucocutaneous apposition, but a second surgery was not recommended for any dog in this study. Because of the small sample size of this study, caution is warranted when evaluating the statistical significance of this difference as just one case suffering major complication would be sufficient to render the difference not significant (P = 0.11).

Increased sneezing and nasal discharge were some of the more common complications noted after surgery site healing, both of which can be inconvenient for owners. Nasal discharge, although more common in the weeks immediately following surgery, decreased to normal levels in all but 2 cases. It is also worth noting that the 2 dogs that experienced increased nasal discharge long-term also had increased nasal discharge before surgery. Increased sneezing commonly persisted past the immediate healing period, remaining above normal levels, in 4 dogs. In addition, 3/4 dogs with increased sneezing did not have sneezing listed among their clinical signs before surgery. These complications, although minor, can be annoying to an owner, likely more so in cases in which these signs were not observed before surgery. Absence pre-operatively leads to the conclusion that these clinical signs are due to the procedure itself rather than the disease process. Persistent nasal discharge and increased sneezing likely result from irritation to the nasal mucosa due to the absence of the nasal planum and its filtering and humidifying effects; a downside of mucocutaneous apposition. No increase in nasal discharge or sneezing were noted as complications in the Dickerson et al study (7). This could represent an oversight on the part of the authors or, more likely, there was increased protection of the nasal mucosa by creation of a pigmented protrusion. In this regard, closure with bilateral buccal mucocutaneous rotation-advancement flaps is superior to closure with mucocutaneous apposition. However, it could be argued that with more pre-operative client education and through managing expectations, owners would be more willing to accept the minor complications of mucocutaneous apposition rather than risk needing a second surgery of higher risk with bilateral buccal mucocutaneous rotation-advancement flaps.

It is possible that the risk for complications following closure may be related to the extent of resection. Removal of bone allows for the availability of more skin during reconstruction and results in less concern for tension and failure. Closure with bilateral buccal mucocutaneous rotation-advancement flaps was originally described by Gallegos et al (4) for reconstruction following nasal planectomy when combined with resection of the incisive bone. In that paper, a concern for increased tension and difficulty of closure in the absence of incisivectomy was noted (4). It is worth mentioning that cases reported by Dickerson et al (7) that underwent closure with bilateral buccal mucocutaneous rotation-advancement flaps following nasal planectomy without incisivectomy all suffered major complications, although the small sample size (n = 2) does not allow for definite conclusions to be drawn. In this study, most cases (54.5%) underwent nasal planectomy without incisivectomy. Although an intact premaxilla would seem to increase the risk for complications due to concern for increased tension, this was not supported by data from this study which showed 0% major complications following closure with mucocutaneous apposition regardless of extent of resection. Facial shape and lip thickness have also been proposed as criteria to guide repair method with more tension noted in patients with wider facial features following reconstruction with bilateral buccal mucocutaneous rotation-advancement flaps (10). However, these associations were explored only in cadavers and further studies are required to determine the effect of the extent of resection, facial shape, and choice of repair technique on complication rates in clinical cases. Because bilateral buccal mucocutaneous rotation-advancement flaps is described for closure following incisivectomy, closure by mucocutaneous apposition is recommended if the premaxilla is intact due to concern for tension and increased risk of major complication.

Another consideration, given the dramatic effect of nasal planectomy on the appearance of the patient, is the cosmesis of the reconstruction. In addition to low complication rates, owner satisfaction with the appearance of their dogs following reconstruction with mucocutaneous apposition and the surgery itself was high. Response to the request for input was excellent with 9/11 owners willing to discuss their experiences. Most owners were either happy with their dog’s appearance or neutral with the single neutral owner stating that the result was as good as could be expected given the nature of the surgery but not something they could be happy about. Seven out of 9 of the owners stated that they would pursue this surgery again in the future. These results are comparable to that reported for repair with bilateral buccal mucocutaneous rotation-advancement flaps which was developed as a more cosmetic method of rostral reconstruction (7). In addition, it is worth noting that 1 of the 2 owners who would not pursue surgery again was the owner of the dog with the shortest survival time following surgery (65 d); this may have influenced their response. This overall owner satisfaction is likely the result of multiple factors including owner preparation in addition to objective cosmesis. For procedures that are likely to have a large effect on the appearance of the patient, preoperative owner education is crucial to set expectations and increase the likelihood of owner satisfaction with the end appearance of the surgical site. Providing photographs for owners to view patients that previously underwent the procedure is useful for client education and was a technique used in the initial consultation for several of the dogs included in this study.

Limitations of this study include its small sample size and retrospective nature. Cases occurred over a prolonged period which, in combination with performance by multiple surgeons, may have led to inconsistencies in terms of case management as well as assessment at follow-up appointments. The rare nature of this disease process also makes obtaining a large sample size difficult. A multi-institutional approach is therefore recommended for follow-up studies to further evaluate the differences in complication rates between methods of reconstruction and to obtain a larger sample size, thereby decreasing the chance for type II error.

Mucocutaneous apposition is a viable surgical option for closure following nasal planectomy with or without incisivectomy and may be recommended over closure by bilateral buccal mucocutaneous rotation-advancement flaps, especially in cases in which the maxilla is left intact. In addition, owner satisfaction with their pet’s appearance following use of this technique is comparable to that reported for techniques developed to better preserve cosmesis if proper steps are taken to prepare expectations before surgery. CVJ