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Novel treatment of a septal ulceration using an extracellular matrix scaffold (septal ulceration treatment using ECM)
AM ER IC AN JOURNAL OF OT OLARYNGOLOGY–H E A D A N D NE CK M E D IC IN E A ND S U RGE RY 3 7 (2 0 1 6) 1 95–1 9 8
Available online at www.sciencedirect.com
ScienceDirect www.elsevier.com/locate/amjoto
Original Contribution
Novel treatment of a septal ulceration using an extracellular matrix scaffold (septal ulceration treatment using ECM)☆ Yi-Chun Carol Liu, MD a,⁎, Nipun Chhabra, MD b , Steven M. Houser, MD, FAAOA c a b c
Department of Pediatric Otolaryngology, Texas Children's Hospital, Houston, TX, USA University of Illinois College of Medicine, Rockford, IL, USA MetroHealth Medical Center, Cleveland, OH, USA
ARTI CLE I NFO
A BS TRACT
Article history:
Background: Septal ulceration is a mucositis involving the mucous membranes of the nasal
Received 24 December 2015
septum. Patients often complain of nasal irritation, crusting, and epistaxis. Presently, there is no gold standard for the treatment of septal ulcerations. Currently described therapies include local debridement, septal dermoplasty, septal flap reconstruction, and cadaveric dermal graft repair; however, no therapy has demonstrated a consistent improvement of symptoms. We present a novel approach for the treatment of chronic septal ulceration, using an extracellular matrix scaffold (MatriStem® Wound Care Matrix, ACell, Inc.) to repair unilateral partial septal mucosal defects. Methods: This is a retrospective chart review of three patients with age range from 42 to 74 years. All three patients underwent several years of unsuccessful conservative medical management and two patients had prior unsuccessful septoplasty and septal ulcer debridement procedure. There are no complications noted in the post-operative period. Result: All three patients had complete symptom relief on post-operative visit after chronic septal ulceration repair using an extracellular matrix scaffold mechanism. Patients were able to manage with conservative nasal regiment after surgery with significant improvement on quality of life. Conclusion: The use of extracellular matrix scaffolding provides the nasal septum with a framework for the in-growth of healthy mucosa over ulcerated areas. We propose this as a new treatment approach for patients who failed conservative medical management. Chronic septal ulcerations can be healed to provide improved quality of life to patients. © 2016 Elsevier Inc. All rights reserved.
1.
Introduction
Septal ulceration is an erosion of the nasal septal lining and surrounding mucosa. The condition may occur unilaterally or ☆
in severe cases, bilaterally. Patients most commonly complain of nasal irritation, foreign body sensation, crust formation, and epistaxis. A nasal septal ulcer may include just the surface epithelium, exposing submucosa, or extend through
The authors have no funding, financial relationships, or conflicts of interest to disclose. ⁎ Corresponding author at: Department of Otolaryngology–Head and Neck Surgery, Pediatric Otolaryngology, Texas Children's Hospital, 6701 Fannin, Suite 640, Houston, TX 77030, USA. Tel.: + 1 832 822 3267; fax: +1 832 825 3251. E-mail address: [email protected] (Y.-C.C. Liu). http://dx.doi.org/10.1016/j.amjoto.2016.01.013 0196-0709/© 2016 Elsevier Inc. All rights reserved.
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AM ER IC AN JOURNAL OF OT OLA RYNGOLOGY–H E A D A N D NE CK M E D ICI N E AN D S U RGE RY 3 7 (2 0 1 6) 1 95 –1 9 8
submucosa and expose perichondrium or cartilage, or even extend through cartilage and expose the opposite perichondrium or submucosa. The defects may arise from trauma, chemical exposure, iatrogenic injury, or idiopathic causes. Nasal septal mucosal defects do not heal well by secondary intention due to exudation and crusting [1]. Non-healing mucosal defects progress to septal ulcers, which are often painful and can significantly affect patient quality of life. We report three cases of persistent septal ulceration that failed conservative and surgical measures and was ultimately repaired with ACell's MatriStem® Wound Care Matrix. These are the first reported cases of an extracellular matrix scaffold as a treatment for chronic septal ulceration.
2.
Case series
Three patients with persistent septal ulceration were seen in a tertiary care medical center. All three patients had failed several years of conservative and surgical measures and were offered the treatment of ACell's MatriStem® Wound Care Matrix repair. The first patient was a 49-year-old man with a history of HIV and hepatitis B who presented with persistent crusting and pain from a chronic, non-healing ulceration of the left nasal septum. He had been managed for several years with nasal emollients and local tissue debridement, and had failed surgical intervention with septoplasty and excision of ulcerated tissue followed by application of silastic sheeting. Physical exam demonstrated a recurrent 2-cm left anterior septal ulcer while the right septal mucosa was healthy. The second patient was a 42-year-old woman presented with persistent crusting and daily epistaxis from a chronic, nonhealing ulceration of left nasal septum. She had been managed for several years with conservative nasal irrigation and emollients without significant symptomatic relief. Physical exam demonstrated a left anterior septal ulcer measuring 1.5 × 2 cm. The third patient was a 74-year-old female who had suffered from a left septal ulcer for years. Nasal jelly and Bactroban had managed to reduce the ulcer from 1.5 × 1.5 cm to 1 × 1 cm but she remained irritated at the site with crusting and some bleeding. he first two patients underwent wide local excision of the ulcerated tissue bed with repair using an extracellular matrix scaffold in the operating room. In the first patient, a thick fibrinous scar was noted intraoperatively deep to a crusted portion of the ulcer, which was consistent with incomplete epithelialization of the previous surgical site (Fig. 1). Additionally, in the area of the posterior ulcer the septal mucosa was very thin and adherent to the contralateral mucosa without evidence of normal intervening cartilage. The septal ulceration in the second patient extended beyond an inferior left septal deflection, thus the septal deflection is unlikely to be the sole cause of her ulceration. The ulcers were debrided of weak mucosa with mastoid curettes to reach bleeding tissue which might serve as a good recipient bed. For the first patient, a single sheet of 2 × 4 cm MatriStem® Wound Care Matrix was trimmed in half, layered, and fashioned in place over the center of another 2 × 4 cm graft.
Fig. 1 – Thick fibrinous scar was noted deep to a crusted portion of the ulcer after removal of the crust and debridement.
The three layers of MatriStem Wound Care Matrix were then sutured, secured, and placed into the left nasal cavity as an overlay graft to the septal ulcer. The MatriStem Wound Care Matrix sheets were then secured to the septum itself with 4-0 Vicryl suture in a quilted fashion (Fig. 2). While the senior author normally uses chromic or gut sutures in the nose, Vicryl was used as Acell was seen to break down chromic sutures in a septal perforation repair; Vicryl stands up to the Acell well though may require extraction in the office. For the second patient, a single sheet of 4 × 7 cm matrix was trimmed into thirds and layered into the left nasal cavity as a three layer onlay graft to the septal ulcer.
Fig. 2 – Illustration of how the MatriStem® Wound Care Matrix was designed and used as overlay graft to the septal ulcer.
AM ER IC AN JOURNAL OF OT OLARYNGOLOGY–H E A D A N D NE CK M E D IC IN E A ND S U RGE RY 3 7 (2 0 1 6) 1 95–1 9 8
Silastic splints coated in antibiotic ointment were then inserted into the nasal cavity so as to oppose the MatriStem® Wound Care Matrix sheets against the ulcer bed (Fig. 3). A second silastic splint was placed in the opposite nasal fossa and these were secured in standard fashion using a 2-0 nonabsorbable suture and kept in place for three weeks. At the three-week follow-up visit, the silastic splints were removed. The third patient was treated in the office: the ulcer was similarly debrided and a 1.5 cm Acell disc was placed over the defect. Silastic sheeting was placed over the site and sutured in placed with a single 4-0 Nylon suture. The silastic was removed at 3 weeks. The first patient exhibited excellent signs of healing. The anterior aspect of the ulcer showed mucosal overgrowth covering the defect while the posterior region was still covered with the extracellular matrix, which was left undisturbed to promote further healing. At the 5-month postoperative visit, the septal ulcer bed was healed, but left a 5 × 5-mm spot of thin mucosa overlying what appeared to be cartilage in the central region. Overall, complete symptomatic relief was obtained with no further crusting or epistaxis. The second and third patients obtained complete closure of their defects, also with symptomatic relief. Their ulcers became level with the surrounding mucosa but maintained a white appearance suggesting scar (Fig. 4). A lack of crusting at the sites suggested fully functional mucociliary clearance despite the color differences seen.
3.
Discussion
Nasal septal ulcers are bothersome to patients and may pose a significant reconstructive challenge. Currently, there is no gold standard for treatment of nasal septal ulcers. A search of English journal articles in PubMed using keywords “septal ulcer”, “septal mucositis” and “nasal mucositis” returned with sixty-eight results since 1960. After reviewing all results from the search, five articles were identified with information
Fig. 3 – Silastic splints coated in antibiotic ointment were used to the MatriStem® Wound Care Matrix sheets against the ulcer bed.
197
Fig. 4 – Post-operative follow-up picture of the third patient showing complete closure of the septal ulceration defects.
regarding nasal septal ulcers of varying etiologies and their treatments. There are few well-described techniques for the repair of septal ulcers, but this is the first published report of using extracellular matrix. One such technique has been proposed for patients with Osler–Weber–Rendu syndrome. In these patients, the anterior third of the nasal mucosa is chronically traumatized from bleeding, cauterization, and packing. Saunders [2] described septal dermoplasty in which he used a split-thickness skin graft and fixed it to the anterior third of both sides of the nasal septum after the septal mucosa was removed. The graft was secured in place with packing. The morbidity of septal dermoplasty includes donor site complications from graft harvesting, wound contracture at the recipient site, and subsequent desquamation of the squamous epithelium. The desquamation of the epithelium produces thick and odorous nasal secretions which require aggressive nasal hygiene protocols [3]. Another technique was described by Bernstein and Bernstein [1] to repair a large mucosal and perichondrial defect from Moh's surgery. A free graft of nasal mucosa was harvested from the ipsilateral inferior turbinate. The primary morbidity of this approach relates to donor site crusting, bleeding, bony exposure, and removal of superficial turbinate mucosa. To avoid donor site morbidity, Cohen and Mirza [4] used AlloDerm™ (acellular human dermal allograft) for repair of partial and total nasal septal mucosal defects. AlloDerm™ is processed from human allograft skin and is immunologically inert. The dermal matrix provides a template for the patient's own fibroblasts and endothelial cells to repopulate and revascularize the area [5]. The senior author had trialed Alloderm for septal ulcer repair as well and found the results unsatisfactory, therefore another repair method was sought out. Currently, there has been no report of using an extracellular matrix scaffold as a treatment for chronic septal ulceration. ACell's MatriStem® Wound Care Matrix is a naturally occurring bioscaffold derived from porcine tissue. The MatriStem sheet is designed to be placed into a wound to be resorbed and later replaced with new native tissue from the host. In our case, the MatriStem® Wound Care Matrix serves as
198
AM ER IC AN JOURNAL OF OT OLA RYNGOLOGY–H E A D A N D NE CK M E D ICI N E AN D S U RGE RY 3 7 (2 0 1 6) 1 95 –1 9 8
a scaffold for the migration of native respiratory epithelium across the septal defect and is a suitable method for the repair of partial thickness ulcers. The MatriStem® Wound Care Matrix provides a reliable scaffolding for mucosal healing after debridement of septal ulcers. This novel approach for septal ulceration repair should be considered for patients who have failed conventional management.
4.
Conclusion
The use of extracellular matrix scaffolding provides the nasal septum with a framework for the ingrowth of healthy mucosa over ulcerated or traumatized areas. We recommend scraping the ulcer to obtain a bleeding bed. The Acell can be secured with Vicryl or non-absorbable suture material and should be covered with silastic for perhaps three weeks to promote
proper healing. Septal ulcers can be healed bringing great symptomatic relief to patients.
REFERENCES
[1] Bernstein TH, Berstein P. The turbinate flap for reconstruction of nasal septal mucosal defects. Laryngoscope 1996;106:1047–8. [2] Saunders WH. Permanent control of nosebleeds in patients with hereditary hemorrhagic telangiectasia. Ann Intern Med 1960;53:147–52. [3] Zohar Y, Sadov R, Shvili Y, et al. Surgical management of epistaxis in hereditary hemorrhagic telangiectasia. Arch Otolaryngol Head Neck Surg 1987;113:754–7. [4] Cohen NA, Mirza N. Acellular human dermal allograft in repair of unilateral partial-thickness and full-thickness nasal septal mucosal defects. Laryngoscope 2000;110:2005–7. [5] Youssef AM. Use of acellular human dermal allograft in tympanoplasty. Laryngoscope 1999;109:1832–3.
Available online at www.sciencedirect.com
ScienceDirect www.elsevier.com/locate/amjoto
Original Contribution
Novel treatment of a septal ulceration using an extracellular matrix scaffold (septal ulceration treatment using ECM)☆ Yi-Chun Carol Liu, MD a,⁎, Nipun Chhabra, MD b , Steven M. Houser, MD, FAAOA c a b c
Department of Pediatric Otolaryngology, Texas Children's Hospital, Houston, TX, USA University of Illinois College of Medicine, Rockford, IL, USA MetroHealth Medical Center, Cleveland, OH, USA
ARTI CLE I NFO
A BS TRACT
Article history:
Background: Septal ulceration is a mucositis involving the mucous membranes of the nasal
Received 24 December 2015
septum. Patients often complain of nasal irritation, crusting, and epistaxis. Presently, there is no gold standard for the treatment of septal ulcerations. Currently described therapies include local debridement, septal dermoplasty, septal flap reconstruction, and cadaveric dermal graft repair; however, no therapy has demonstrated a consistent improvement of symptoms. We present a novel approach for the treatment of chronic septal ulceration, using an extracellular matrix scaffold (MatriStem® Wound Care Matrix, ACell, Inc.) to repair unilateral partial septal mucosal defects. Methods: This is a retrospective chart review of three patients with age range from 42 to 74 years. All three patients underwent several years of unsuccessful conservative medical management and two patients had prior unsuccessful septoplasty and septal ulcer debridement procedure. There are no complications noted in the post-operative period. Result: All three patients had complete symptom relief on post-operative visit after chronic septal ulceration repair using an extracellular matrix scaffold mechanism. Patients were able to manage with conservative nasal regiment after surgery with significant improvement on quality of life. Conclusion: The use of extracellular matrix scaffolding provides the nasal septum with a framework for the in-growth of healthy mucosa over ulcerated areas. We propose this as a new treatment approach for patients who failed conservative medical management. Chronic septal ulcerations can be healed to provide improved quality of life to patients. © 2016 Elsevier Inc. All rights reserved.
1.
Introduction
Septal ulceration is an erosion of the nasal septal lining and surrounding mucosa. The condition may occur unilaterally or ☆
in severe cases, bilaterally. Patients most commonly complain of nasal irritation, foreign body sensation, crust formation, and epistaxis. A nasal septal ulcer may include just the surface epithelium, exposing submucosa, or extend through
The authors have no funding, financial relationships, or conflicts of interest to disclose. ⁎ Corresponding author at: Department of Otolaryngology–Head and Neck Surgery, Pediatric Otolaryngology, Texas Children's Hospital, 6701 Fannin, Suite 640, Houston, TX 77030, USA. Tel.: + 1 832 822 3267; fax: +1 832 825 3251. E-mail address: [email protected] (Y.-C.C. Liu). http://dx.doi.org/10.1016/j.amjoto.2016.01.013 0196-0709/© 2016 Elsevier Inc. All rights reserved.
196
AM ER IC AN JOURNAL OF OT OLA RYNGOLOGY–H E A D A N D NE CK M E D ICI N E AN D S U RGE RY 3 7 (2 0 1 6) 1 95 –1 9 8
submucosa and expose perichondrium or cartilage, or even extend through cartilage and expose the opposite perichondrium or submucosa. The defects may arise from trauma, chemical exposure, iatrogenic injury, or idiopathic causes. Nasal septal mucosal defects do not heal well by secondary intention due to exudation and crusting [1]. Non-healing mucosal defects progress to septal ulcers, which are often painful and can significantly affect patient quality of life. We report three cases of persistent septal ulceration that failed conservative and surgical measures and was ultimately repaired with ACell's MatriStem® Wound Care Matrix. These are the first reported cases of an extracellular matrix scaffold as a treatment for chronic septal ulceration.
2.
Case series
Three patients with persistent septal ulceration were seen in a tertiary care medical center. All three patients had failed several years of conservative and surgical measures and were offered the treatment of ACell's MatriStem® Wound Care Matrix repair. The first patient was a 49-year-old man with a history of HIV and hepatitis B who presented with persistent crusting and pain from a chronic, non-healing ulceration of the left nasal septum. He had been managed for several years with nasal emollients and local tissue debridement, and had failed surgical intervention with septoplasty and excision of ulcerated tissue followed by application of silastic sheeting. Physical exam demonstrated a recurrent 2-cm left anterior septal ulcer while the right septal mucosa was healthy. The second patient was a 42-year-old woman presented with persistent crusting and daily epistaxis from a chronic, nonhealing ulceration of left nasal septum. She had been managed for several years with conservative nasal irrigation and emollients without significant symptomatic relief. Physical exam demonstrated a left anterior septal ulcer measuring 1.5 × 2 cm. The third patient was a 74-year-old female who had suffered from a left septal ulcer for years. Nasal jelly and Bactroban had managed to reduce the ulcer from 1.5 × 1.5 cm to 1 × 1 cm but she remained irritated at the site with crusting and some bleeding. he first two patients underwent wide local excision of the ulcerated tissue bed with repair using an extracellular matrix scaffold in the operating room. In the first patient, a thick fibrinous scar was noted intraoperatively deep to a crusted portion of the ulcer, which was consistent with incomplete epithelialization of the previous surgical site (Fig. 1). Additionally, in the area of the posterior ulcer the septal mucosa was very thin and adherent to the contralateral mucosa without evidence of normal intervening cartilage. The septal ulceration in the second patient extended beyond an inferior left septal deflection, thus the septal deflection is unlikely to be the sole cause of her ulceration. The ulcers were debrided of weak mucosa with mastoid curettes to reach bleeding tissue which might serve as a good recipient bed. For the first patient, a single sheet of 2 × 4 cm MatriStem® Wound Care Matrix was trimmed in half, layered, and fashioned in place over the center of another 2 × 4 cm graft.
Fig. 1 – Thick fibrinous scar was noted deep to a crusted portion of the ulcer after removal of the crust and debridement.
The three layers of MatriStem Wound Care Matrix were then sutured, secured, and placed into the left nasal cavity as an overlay graft to the septal ulcer. The MatriStem Wound Care Matrix sheets were then secured to the septum itself with 4-0 Vicryl suture in a quilted fashion (Fig. 2). While the senior author normally uses chromic or gut sutures in the nose, Vicryl was used as Acell was seen to break down chromic sutures in a septal perforation repair; Vicryl stands up to the Acell well though may require extraction in the office. For the second patient, a single sheet of 4 × 7 cm matrix was trimmed into thirds and layered into the left nasal cavity as a three layer onlay graft to the septal ulcer.
Fig. 2 – Illustration of how the MatriStem® Wound Care Matrix was designed and used as overlay graft to the septal ulcer.
AM ER IC AN JOURNAL OF OT OLARYNGOLOGY–H E A D A N D NE CK M E D IC IN E A ND S U RGE RY 3 7 (2 0 1 6) 1 95–1 9 8
Silastic splints coated in antibiotic ointment were then inserted into the nasal cavity so as to oppose the MatriStem® Wound Care Matrix sheets against the ulcer bed (Fig. 3). A second silastic splint was placed in the opposite nasal fossa and these were secured in standard fashion using a 2-0 nonabsorbable suture and kept in place for three weeks. At the three-week follow-up visit, the silastic splints were removed. The third patient was treated in the office: the ulcer was similarly debrided and a 1.5 cm Acell disc was placed over the defect. Silastic sheeting was placed over the site and sutured in placed with a single 4-0 Nylon suture. The silastic was removed at 3 weeks. The first patient exhibited excellent signs of healing. The anterior aspect of the ulcer showed mucosal overgrowth covering the defect while the posterior region was still covered with the extracellular matrix, which was left undisturbed to promote further healing. At the 5-month postoperative visit, the septal ulcer bed was healed, but left a 5 × 5-mm spot of thin mucosa overlying what appeared to be cartilage in the central region. Overall, complete symptomatic relief was obtained with no further crusting or epistaxis. The second and third patients obtained complete closure of their defects, also with symptomatic relief. Their ulcers became level with the surrounding mucosa but maintained a white appearance suggesting scar (Fig. 4). A lack of crusting at the sites suggested fully functional mucociliary clearance despite the color differences seen.
3.
Discussion
Nasal septal ulcers are bothersome to patients and may pose a significant reconstructive challenge. Currently, there is no gold standard for treatment of nasal septal ulcers. A search of English journal articles in PubMed using keywords “septal ulcer”, “septal mucositis” and “nasal mucositis” returned with sixty-eight results since 1960. After reviewing all results from the search, five articles were identified with information
Fig. 3 – Silastic splints coated in antibiotic ointment were used to the MatriStem® Wound Care Matrix sheets against the ulcer bed.
197
Fig. 4 – Post-operative follow-up picture of the third patient showing complete closure of the septal ulceration defects.
regarding nasal septal ulcers of varying etiologies and their treatments. There are few well-described techniques for the repair of septal ulcers, but this is the first published report of using extracellular matrix. One such technique has been proposed for patients with Osler–Weber–Rendu syndrome. In these patients, the anterior third of the nasal mucosa is chronically traumatized from bleeding, cauterization, and packing. Saunders [2] described septal dermoplasty in which he used a split-thickness skin graft and fixed it to the anterior third of both sides of the nasal septum after the septal mucosa was removed. The graft was secured in place with packing. The morbidity of septal dermoplasty includes donor site complications from graft harvesting, wound contracture at the recipient site, and subsequent desquamation of the squamous epithelium. The desquamation of the epithelium produces thick and odorous nasal secretions which require aggressive nasal hygiene protocols [3]. Another technique was described by Bernstein and Bernstein [1] to repair a large mucosal and perichondrial defect from Moh's surgery. A free graft of nasal mucosa was harvested from the ipsilateral inferior turbinate. The primary morbidity of this approach relates to donor site crusting, bleeding, bony exposure, and removal of superficial turbinate mucosa. To avoid donor site morbidity, Cohen and Mirza [4] used AlloDerm™ (acellular human dermal allograft) for repair of partial and total nasal septal mucosal defects. AlloDerm™ is processed from human allograft skin and is immunologically inert. The dermal matrix provides a template for the patient's own fibroblasts and endothelial cells to repopulate and revascularize the area [5]. The senior author had trialed Alloderm for septal ulcer repair as well and found the results unsatisfactory, therefore another repair method was sought out. Currently, there has been no report of using an extracellular matrix scaffold as a treatment for chronic septal ulceration. ACell's MatriStem® Wound Care Matrix is a naturally occurring bioscaffold derived from porcine tissue. The MatriStem sheet is designed to be placed into a wound to be resorbed and later replaced with new native tissue from the host. In our case, the MatriStem® Wound Care Matrix serves as
198
AM ER IC AN JOURNAL OF OT OLA RYNGOLOGY–H E A D A N D NE CK M E D ICI N E AN D S U RGE RY 3 7 (2 0 1 6) 1 95 –1 9 8
a scaffold for the migration of native respiratory epithelium across the septal defect and is a suitable method for the repair of partial thickness ulcers. The MatriStem® Wound Care Matrix provides a reliable scaffolding for mucosal healing after debridement of septal ulcers. This novel approach for septal ulceration repair should be considered for patients who have failed conventional management.
4.
Conclusion
The use of extracellular matrix scaffolding provides the nasal septum with a framework for the ingrowth of healthy mucosa over ulcerated or traumatized areas. We recommend scraping the ulcer to obtain a bleeding bed. The Acell can be secured with Vicryl or non-absorbable suture material and should be covered with silastic for perhaps three weeks to promote
proper healing. Septal ulcers can be healed bringing great symptomatic relief to patients.
REFERENCES
[1] Bernstein TH, Berstein P. The turbinate flap for reconstruction of nasal septal mucosal defects. Laryngoscope 1996;106:1047–8. [2] Saunders WH. Permanent control of nosebleeds in patients with hereditary hemorrhagic telangiectasia. Ann Intern Med 1960;53:147–52. [3] Zohar Y, Sadov R, Shvili Y, et al. Surgical management of epistaxis in hereditary hemorrhagic telangiectasia. Arch Otolaryngol Head Neck Surg 1987;113:754–7. [4] Cohen NA, Mirza N. Acellular human dermal allograft in repair of unilateral partial-thickness and full-thickness nasal septal mucosal defects. Laryngoscope 2000;110:2005–7. [5] Youssef AM. Use of acellular human dermal allograft in tympanoplasty. Laryngoscope 1999;109:1832–3.