Microfibrillar Collagen for Hemostasis in

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Ligation and suturing remain the most convenientmethods of hemostasis for most surgical situa-

tions. However, in certain situations, such as largeoozing surfaces or when access to the surgical site ispoor, other management options may be required.The purpose of this report is to describe the manage-ment of bleeding caused by neodymium: yttrium-aluminum-garnet (Nd:YAG) laser surgery usingmicrofibrillar collagen (Avitene). Details of thepatient's clinical course and the hemostasis techniqueare discussed.

CASE REPORT

A 32-year-old man presented with a six-monthhistory of a globus sensation. He denied otalgia,chronic cough, dysphagia, or change of voice.Physical examination revealed normal findingsin ear, nose, nasopharynx, and oropharynx.Examination by flexible endoscopy demonstrated apurple tumor mass with a smooth contour at the rightpyriform sinus. The vocal cord is free in motion.

Case Report

Microfibrillar Collagen for Hemostasis inLaryngomicrosurgery of Hypopharyngeal Hemangioma

Shih-Wei Lee, MD; Tuan-Jen Fang, MD; Ching-Wen Hsu, MD; Hsueh-Yu Li, MD

Hypopharyngeal hemangiomas are uncommon neoplasms that can cause dysphagia,recurrent bleeding, and airway obstruction. These lesions are a therapeutic challenge, andsurgical resection is the mainstay of therapy. The goal of therapy is directed at control of thetumor and relief of symptoms rather than total eradication of the lesion.

Laser therapy is a very useful adjunct in the management of these vascular neoplasms.The neodymium: yttrium-aluminum-garnet laser (Nd:YAG laser) functions at a wavelengththat provides deep thermal coagulation. This allows its use for these vascular lesions. Withlaser surgery, hemorrhage is the most frequent and dangerous complication, and its control isextremely important. Ligation and suture remain the traditional methods of hemostasis inmost surgical situations. However, on certain occasions problems arise, particularly withlarge oozing surfaces or when surgical access is poor. Topical hemostatic agents are widelyused in a variety of surgical procedures to successfully solve such problems. Microfibrillarcollagen (Avitene) is one of the absorbable, topical, hemostatic agents, and is used effective-ly to control bleeding in many surgical situations. Since we began to use microfibrillar colla-gen (AviteneTM, MedchemProduct, Inc., Woburn, MA01801) to stop the massive oozing ofthe laser-induced surgical wound, no episodes of bleeding had ever occurred. It is concludedthat Avitene is an effective agent for maintaining hemostasis in many surgical procedures,and we consider it a good remedy for management of laser-induced bleeding complications.(Chang Gung Med J 2003;26:65-9)

Key words: microfibrillar collagen (Avitene), hypopharyngeal hemangioma, Nd:YAG laser.

From the Department of Otolaryngology, Chang Gung Memorial Hospital, Taipei, Chang Gung University, Taoyuan, Taiwan. Received: Jan. 2, 2002; Accepted: Apr. 26, 2002Address for reprints: Dr. Hsueh-Yu Li, Department of Otolaryngology, Chang Gung Memorial Hospital. 5, Fu Shin Street,Kweishan, Taoyuan 333, Taiwan, R. O. C. Tel.: 886-3-3281200 ext. 3967; Fax: 886-3-3279361; E-mail: [email protected]

Chang Gung Med J Vol. 26 No. 1January 2003

Hsueh-Yu Li, et alHypopharyngeal hemangioma

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Computed tomography (CT) identified extension ofthe lesion into the right para-laryngeal space andslight enhancement of the lesion after intravenouscontrast medium injection (Fig. 1). As angiographyshowed no definite tumor vessels, tumor stain, orabnormal arteriovenous (AV) shunting at the laryn-geal area, embolization was not performed.

The patient underwent suspension microlaryn-goscopy under general anesthesia, revealing ahemangioma of the right hypopharynx (Fig. 2). Weperformed Nd:YAG photocoagulation with the laserset at 15 W in the continuous mode. A profuse ooz-ing was encountered during photoablation, andattempts to achieve hemostasis with compression,pressure, electrocautery, and suture ligatures wereunsuccessful. Thus, we introduced Avitene upon thebleeding site using sterile forceps; then, pressure wasapplied until the bleeding stopped. The blood losswas estimated to be about 100 c.c..

Microscopically, the tumor tissue was composedof aggregates of irregular dilated blood channels andcapillaries lined by flattened endothelium, and thevessels' luminae were filled with blood cells. Thehistopathological diagnosis was hypopharyngealhemangioma (Fig 3). Thereafter, there was noepisode of bleeding. The patient made a good recov-

ery without voice change or airway distress, and wasdischarged on the third postoperative day. He hasdone well, with complete resolution of his symp-toms,although a 3-month follow-up examination inthe office revealed the remaining residual heman-gioma on the right hypopharynx (Fig. 4).Furthermore, no postoperative cicatrix was noted,and the patient had a satisfactory postoperativecourse.

Fig. 2 Preoperative endoscopic findings. The purplish tumormass was in the right pyriform sinus with a smooth contour.

Fig. 1 Horizontal CT scan with contrast enhancementshowed a tumor in the right pyriform sinus with extension tothe right paralaryngeal space.

Fig. 3 Histopathologic section of the excised tumor showingaggregates of irregular dilated blood channels and capillarieslined by flattened endothelium. (H & E 400)



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DISCUSSION

Hypopharyngeal hemangiomas are uncommonneoplasms(1) that can cause dysphagia, recurrentbleeding, and airway obstruction. These lesions are atherapeutic challenge, and surgical resection is themainstay of therapy. Hypopharyngeal hemangiomasare usually of the cavernous or mixed type, with athin, friable mucosa overlying the vascular stroma.(2)

Preoperative CT with contrast enhancement andangiography are helpful in both planning the surgicalprocedure and avoiding injury to adjacent vessels.Laser therapy is a very useful adjunct in the manage-ment of these vascular neoplasms.

Photocoagulation with the Nd:YAG laser offersthe clinician an effective alternative therapy to opensurgical procedures. The Nd:YAG laser, at 1.06 µm,has the longest penetration depth of any of the surgi-cal lasers. The tissue characteristics of the Nd:YAGlaser result in deep penetration and scatter of laserenergy that is preferentially absorbed by pigmentedor vascular tissue. This laser produces a homogenouszone of thermal coagulation and necrosis that mayextend 4 µm from the impact site, thereby providingdeep thermal coagulation.(3) These characteristicsallow its use for vascular lesions. If too much laserenergy is directed in one spot, the result may bemucosal disruption and hemorrhage. Excessivebleeding also results from extravasation of the con-

tents of the hemangioma into adjacent normal tissue,or rupture of the capsule. Hemorrhage is the mostfrequent and dangerous complication associated withlaser surgery, and its control is extremely important.In our case, the patient did not undergo superselec-tive embolization because there were no definitetumor vessels, tumor stain, or abnormal AV shuntingin the laryngeal area on angiography.

As hemangiomas are benign lesions, it is betterto undertreat them and monitor their evolution overtime than to damage healthy tissue. The goal of ther-apy is directed at control of the tumor and relief ofsymptoms rather than total eradication of thelesion.(4)

Ligation and suture remain the traditional meth-ods of hemostasis in most surgical situations.However, on certain occasions problems arise, par-ticularly with large oozing surfaces or when surgicalaccess is poor. Topical hemostatic agents are widelyused in a variety of surgical procedures. Microfi-brillar collagen (Avitene) is an absorbable, topical,hemostatic agent that is used effectively to controlbleeding in many surgical situations. It is insolublein water and consists of a dry, fluffy, off-white pow-der. It provides a surface for platelet adhesion. Theplatelets adhere to the collagen surface and thenundergo a release reaction that leads to aggregationof surrounding platelets and clot formation. Aviteneis inactivated by autoclaving and, therefore, cannotbe reused. Avitene is used by applying the powderwith dry instruments to the bleeding site, which haspreviously been cleaned of excess blood.(5) Pressureis placed to the area of application. When hemosta-sis occurs, the excess Avitene that has not beenincorporated into the clot is removed gradually.Recurrence of bleeding following removal of excesscollagen can be controlled by reapplication. Topicalhemostatic agents are potentiators of infection andshould be used in the smallest quantities possiblewhere a risk of bacterial contamination exists.(6)

Uses of Avitene in otorhinolaryngologic surgeryhave been described in nonsurgical repair ofextratemporal facial nerves,(7) tracheal autograft pre-fabrication,(8) and hemostasis in epistaxis.(9)

It is important to note that topical hemostaticagents are not used to stop arterial bleeding. Rather,they are used to control oozing from raw surfaces.Avitene offers effective hemostasis of diffuse oozingsurfaces, such as occurs with laser surgery.

Fig. 4 Postoperative flexible fiberoptic nasopharyngoscopy 3months after tumor excision. The residual hemangiomaremains on the right hypopharynx. No postoperative cicatrixis noted.



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Precautions against aspiration should includeremoval of all excess dry material. To the best of theauthors' knowledge, there is no previous report ofbleeding management with microfibrillar collagenfor control of oozing blood loss as a complication oflaser laryngomicrosurgery.

In conclusion, microfibrillar collagen can beused as an adjunct in hemostasis when control ofbleeding by ligature or conventional procedures isineffective or impractical. From our experience, wefound that it is a good remedy for management ofbleeding as a complication of laser surgery.

REFERENCES

1. Guo YC, Chu PY, Ho DM, Chang SY. Hemangioma ofthe pyriform sinus. Otolaryngol Head Neck Surg 2001;124:707-8.

2. Sie KC, Tampakopoulou DA. Hemangioma and vascularmalformations of the airway. Otolaryngol Clin North Am2000;33:209-20.

3. Courey MS, Ossoff RH. Laser applications in adult laryn-geal surgery. Otolaryngol Clin North Am 1996;29:973-84.

4. Yellin SA, Labruna A, Anand VK. Nd:YAG laser treat-ment for laryngeal and hypopharyngeal hemangioma: anew technique. Ann Otol Rhinol Laryngol 1996; 105:510-15.

5. Decker CJ. An efficient method for the application ofAvetene hemostatic agent. Surg Gynecol & Obstet 1991;172:489.

6. Kenneth SS, James A CJ. Effects of oxidized celluloseand microfibrillar collagen on infection. Surgery 1982;91:301-4.

7. Parker G. Surgical repair of extratemporal facial nerve: acomparison of suture repair and microfibrillar collagenrepair. Laryngoscope 1984;94:950-3.

8. Daniel BK, Jose NF. Tracheal autograft prefabricationusing microfibrillar collagen and bone morphogeneticprotein. Arch Otolaryngol Head Neck Surg 1996;122:1385-9.

9. Walike JW, Chinn J. Evaluation and treatment of acutebleeding from the head and neck. Ear Nose Throat ClinNorth Am 1979;12:455-63.

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91 1 2 91 4 26333 5 Tel.: (03)3281200 3967; Fax: (03)

3979361; E-mail: [email protected]

AviteneAvitene

AviteneAvitene 31

(Nd-Yag laser) (ooz-ing) Avitene

100 ccAvitene

( 2003;26:65-9)

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Microfibrillar Collagen for Hemostasis in