Endoscopic Repair of Internal Carotid Artery Injury with a Lateral Tongue Muscle Patch Graft: Novel Technique and Literature Review

Abstract

Objectives  Iatrogenic injury to the internal carotid artery (ICA) is one of the most catastrophic complications of endoscopic sinus and skull base surgery. Previous research has shown that packing with a crushed muscle graft at the injury site can be an effective management technique to control bleeding and prevent the need for ICA sacrifice. Here, we describe a novel and readily available repair donor site—an autologous lateral tongue muscle patch.

Design  Three representative cases of a successful repair of ICA injuries using a lateral tongue muscle patch are included in this study. The graft measured approximately 2 × 3 cm and was taken from the lateral intrinsic tongue musculature. We describe the harvest of the graft, its advantages, and the details of operative repair.

Results  The lateral tongue provides a large and readily accessible source of muscle within the surgical field that can be quickly harvested during an endoscopic procedure. For the first case, an expanding parasellar ICA pseudoaneurysm was managed with a tongue muscle patch and nasal packing. In the second case, a cavernous ICA injury was sustained during craniopharyngioma resection. Case three involved an ICA injury during endonasal debridement of invasive fungal rhinosinusitis. None of the patients required embolization or neurovascular stenting. Postoperative angiograms and serial computed tomography angiograms showed complete resolution of the pseudoaneurysm, and the patients continued to do well at least 1 year after repair.

Conclusion  Lateral tongue muscle graft is an effective and efficient method to manage ICA injuries during endoscopic endonasal surgery. Advantages include the speed of harvest, donor site being readily accessible in the surgical field, and low donor site morbidity. It should be added to the repertoire of possible donor sites for addressing catastrophic sinonasal bleeding.

Introduction

Major complications in endoscopic endonasal surgery occur at a rate of less than 1%, with some of the most common being epistaxis, cerebrospinal fluid leak, meningitis, and intracranial penetration. ^{1 2} Internal carotid artery (ICA) injury remains a feared and debilitating complication that can often result in serious morbidity and mortality. ³ Injury to the ICA can result in profound neurological complications and death. The true incidence of ICA injury during endoscopic sinus and skull base surgery is variable, but it is generally considered rare, with the literature primarily consisting of case reports, subsets of large endoscopic databases, and expert opinions. ^{4 5} Studies involving large aggregates of patients show an overall incidence rate of 0.01%. ⁴ Although relatively rare, current literature estimates that around 20% of endoscopic skull base surgeons experienced an ICA injury in their career ⁶ .

Muscle grafts prove to be one of the most effective methods of controlling hemorrhage in ICA injuries. ^{7 8 9} Several different donor sites for crushed muscle grafts have been described, including the sternocleidomastoid (SCM), nasopharynx, and tensor fascia lata. ^{4 10 11} Several emergency protocols and management strategies involving muscle or fascia grafts for immediate control of ICA hemorrhage have been published since 2005. ^{9 11 12 13 14 15} In sheep models, the use of muscle patches from the SCM has shown low rates of destabilization and pseudoaneurysm formations, as well as maintenance of normal vessel characteristics and patency. ¹³ In a model created by Wormald et al comprising 20 sheep, a muscle patch, U-clip, and chitosan gel were compared against each other. Results showed that the muscle patch hemostasis and the U-Clip anastomotic device were superior in achieving primary hemostasis, reducing total blood loss, and finally, improving survival time over any other packing, including Floseal, oxidized regenerated cellulose, and Chitosan gel. This model not only showed that muscle patches prevent mortality and improve hemostasis but also showed that vascular occlusion is not necessary to stop bleeding. ¹³

Here, we describe a novel and readily available repair donor site—an autologous lateral tongue muscle patch. This strategy for hemostasis and injury repair includes muscle graft overlay from specifically the tongue, which can allow for rapid control without the need for additional sterile preparation of other parts of the body such as the SCM. This is the first published series demonstrating the effectiveness of the lateral tongue muscle as an easy and effective graft for controlling ICA injuries. Here, we describe and advocate for the use of an autologous lateral tongue muscle graft for prompt and effective repair of ICA injuries.

Methods

We describe three representative cases of successful repair of ICA injuries using a lateral tongue muscle patch. All cases were performed at a large academic medical center between 2005 and 2022 by three different surgeons. We describe the harvest of the graft, its advantages, and the details of operative repair. This case series was exempt from Institutional Review Boards approval at Vanderbilt University Medical Center.

Operative Technique

Fig. 1 illustrates the process of harvesting the lateral tongue graft and applying it to the ICA. Our patients routinely get Unasyn or similar antibiotics intraoperatively as prophylaxis to cover oral and respiratory flora. A quick prep with chlorhexidine 0.12% oral solution may be utilized prior to graft harvest. The tongue is grasped with a towel clamp or a Debakey forceps to expose, and a 2 × 3 cm wedge of the tongue is resected with a 15-blade or the bovie cautery. The lateral tongue graft is soaked in saline, then crushed and flattened and the muscle (rather than mucosal) surface is placed on the defect with cessation of hemorrhage. It is subsequently packed with absorbable hemostatic material such as Surgicel, Gelfoam, or gauze to hold the graft in position. Vicryl sutures are used to close the donor site defect.

Fig. 1.

Artist illustration demonstrating the operative steps of harvesting the lateral tongue muscle graft and applying it endoscopically to the site of internal carotid artery (ICA) injury. (A) Demonstrates a high-speed drill injury to the left cavernous ICA segment with subsequent catastrophic bleeding. (B) Approximately 2 × 3 cm lateral tongue patch of muscle is quickly harvested from lateral tongue intrinsic muscle using a 15-scalel or bovie cautery. (C) Crushed muscle patch is applied over the carotid defect after obtaining appropriate endoscopic exposure. (D) Repair is bolstered with nasal packing. The surgeon may additionally utilize a pedicled nasoseptal flap.

Results

Case 1: 24-Year-Old Female Who Presented with Recurrent High-Volume Epistaxis 3-Weeks after Endoscopic Sinus Surgery

A 24-year-old female with chronic rhinosinusitis presented to the emergency department 3 weeks after endoscopic sinus surgery (ESS) at some other hospital. Upon presentation, the patient had significant epistaxis requiring blood transfusions for hemoglobin levels as low as 6.0. She was taken to the operating room where a bovie artifact was identified in the sphenoid optic-carotid recess concerning for IAC injury ( Fig. 2 ). The patient subsequently received a diagnostic angiogram which identified a right cavernous ICA parasellar pseudoaneurysm at the site of the bovie artifact. A repeat angiogram a few days later (postoperative day 35 from the original surgery) showed an interval increase in the size of the pseudoaneurysm ( Fig. 2 ). She was evaluated by the neurovascular team; however, due to the small size of the pseudoaneurysm, she was a poor candidate for embolization, and stent placement was deemed too high risk of morbidity given risks of anticoagulation in this 24-year-old patient and the possibility of ophthalmic artery occlusion and stent extrusion. Hence, our plan was to place the stent inpatient if the graft failed.

Fig. 2.

Endoscopic view of eschar from bovie artifact in the opticocarotid recess and an angiogram showing an expanding parasellar internal carotid artery pseudoaneurysm. (A) Eschar in the right sphenoid opticocarotid recess concerning for cauterization injury. (B) Angiography showing a 3 mm parasellar ICA pseudoaneurysm.

After experiencing another episode of spontaneous, large-volume epistaxis during her hospital stay, she was taken emergently to the operating room. An endoscopic examination of the sphenoid sinus demonstrated the carotid pseudoaneurysm with profuse bleeding. Additional exposure of the ICA was not necessary given obvious site of injury in this patient. A lateral tongue muscle graft was harvested from the right lateral aspect of the tongue, which was already within the operative field. The muscle graft was flattened and placed over the carotid pseudoaneurysm, with immediate control of hemorrhage. All operative surfaces were covered with Surgifoam with thrombin. Vicryl sutures were used to close the donor site defect. The graft was left packed for 2 weeks with absorbable hemostatic materials—Surgicel, Gelfoam or strip gauze to hold the graft in position. Computerized tomography angiogram (CTA) of the head after repair showed no active extravasation ( Fig. 3 .). She was discharged home and had no additional bleeding or evidence of pseudoaneurysm on the CTA at her 1-year follow-up.

Fig. 3.

CT angiography and angiography demonstrating complete resolution of internal carotid artery (ICA) pseudoaneurysm after a lateral tongue muscle patch skull base repair. (A) 2-week postrepair coronal and sagittal CTA imaging for Case #1 (post-ESS delayed pseudoaneurysm rupture repair). (B) Postoperative day 1 angiography for Case #2 (intraoperative injury during craniopharyngioma skull base tumor resection).

Case 2: 69-Year-Old Male with Intraoperative Internal Carotid Artery Injury Sustained during a Craniopharyngioma Resection

A 69-year-old male was admitted to the hospital due to the change in mental status and found to have a suprasellar mass. He was subsequently taken to the operating room for an expanded transsphenoidal approach for resection with otolaryngology- and neurosurgery-specialized teams. During our standard “Mercedes sign” radial incision into the dura, brisk arterial bleeding was encountered from a small ICA side wall injury. The site of the injury was endoscopically visualized, and carotid injury protocols were initiated. Immediately, attention was turned to the donor site to obtain a 2 ×3 cm lateral tongue graft which was used to successfully control the acute bleeding. Postoperative angiography showed no obvious arterial extravasation, and no further intervention was undertaken. After stabilization, the patient was taken for definitive resection of the tumor with final pathology consistent with craniopharyngioma. He had no further hemorrhage while admitted and had no additional bleeding or morbidity at follow-up over 1-year later.

Case 3: 40-Year-Old Male with Internal Carotid Artery Injury during Debridement of Invasive Fungal Rhinosinusitis

A 40-year-old male with poorly controlled diabetes mellitus was transferred for the management of invasive fungal rhinosinusitis following an outside biopsy consistent with mucormycosis. CT imaging revealed orbital involvement with bony destruction of the left lamina papyracea, orbital floor, and left orbital fissure. The patient was taken promptly to the operating room for endoscopic nasal debridement and radical orbitotomy. Intraoperatively, necrotic and friable bone overlying the cavernous ICA dehisced and brisk hemorrhage was encountered. An injury of the ICA was directly visualized to be the source of the hemorrhage and was not amenable to electrocautery or clipping. Ribbon gauze packing was applied to the defect to obtain control of the hemorrhage and allow for visualization. Meanwhile, a muscle graft was rapidly harvested from the left lateral tongue with a scalpel, and then crushed and flattened. The ribbon gauze packing was removed, and the muscle graft was gently placed at the focus of hemorrhage under endoscopic visualization. Care was taken to ensure the maintenance of flow through the vessel and the hemorrhage immediately ceased. The tongue donor site was closed primarily with absorbable interrupted sutures.

Postoperative serial examination revealed no new postoperative neurological deficits. Hemostasis was maintained, and the patient remained hemostatic and neurologically intact for the remainder of his hospital course. He was returned to the operating room on postoperative day 9 for the removal of his nasal and orbital packing, and no further hemorrhage was noted. A postoperative contrasted CT of the head showed no evidence of intravascular thrombus or pseudoaneurysm. He was discharged to home under hospice care on postoperative day 30 and has declined requests for follow-up imaging but reported no issues otherwise.

Discussion

Rapid control of ICA hemorrhage can be challenging and requires teamwork, intraoperative decision-making and immediate intervention. ¹⁶ Although relatively rare, current literature estimates that around 20% of endoscopic skull base surgeons have experienced an ICA injury in their careers. ⁶ In this manuscript, we describe the operative technique ( Fig. 1 ) and the advantages of a lateral tongue graft for the repair of iatrogenic injuries of the internal carotid. Previous studies using animal models have already established the utility and superiority of muscle grafts from the SCM over other hemostatic measures such as fibrin-based gel and packing. However, one of the major advantages of the lateral tongue graft is a readily available reservoir of muscle that is easily accessed within the surgical field during an emergency. ¹³ In addition, prompt repair of ICA injuries with this technique may avoid the need of ICA sacrifice. There were no major complications to report during short or long-term follow-up.

Muscle grafts prove to be one of the most effective methods of controlling hemorrhage in ICA injuries. Several different donor sites for crushed muscle grafts have been described, including the SCM, nasopharynx, and tensor fascia lata. ^{4 10 11} A number of emergency protocols and management strategies involving muscle or fascia grafts for immediate control of ICA hemorrhage have been published since 2005 ^{9 11 12 13 14 15} In sheep models, the use of muscle patches from the SCM has shown low rates of destabilization and pseudoaneurysm formations, as well as maintenance of normal vessel characteristics and patency. ¹³ In a model created by Wormald et al, comprising 20 sheep, a muscle patch, U-clip, and chitosan gel were compared against each other. Results showed that the muscle patch hemostasis and the U-Clip anastomotic device were superior in achieving primary hemostasis, reducing total blood loss, and finally improving survival time over Floseal, oxidized regenerated cellulose, and Chitosan gel. This model not only showed that muscle patches prevent mortality and improve hemostasis, but also showed that vascular occlusion is not necessary to stop bleeding. ¹³ Valentine and Wormald have published a comprehensive review of the literature regarding ICA following endonasal surgery, including the various treatment options available. ⁸ Previously tried materials include packing with conventional hemostatic methods such as thrombin-based meshes, gauze, cotton pledgets, or cellulose packing followed by endovascular intervention with embolization, stenting, or ICA sacrifice. ^{3 12}

Rapid control of hemorrhage is imperative in ICA injuries. Notably, a harvest of muscle grafts from the SCM or other locations requires redraping and sterile prep of a new part of the body which can cost valuable time in these cases. In contrast, lateral muscle graft harvest takes only 1 to 2 minutes, requiring very little to no redraping and sterilization, even by an inexperienced surgeon and in cases where such injuries may be unplanned for. Additional advantages include the speed of harvest, the donor site being readily accessible in the surgical field, and low donor site morbidity. Following our three cases, patients did not require any additional endovascular interventions to achieve hemostasis including stenting or embolization ( Figure 3 ). There is a risk of delayed pseudoaneurysm formation for many months after injury, and delayed CTA imaging or angiography should be performed for surveillance. In all three of our cases, radiological follow-up was obtained at 1 to 2 weeks, 3 months, and 1-year intervals postintervention, all without evidence of pseudoaneurysm formation.

Nasal operative procedures such as ESS are not considered sterile, and application of a nonsterile muscle graft is appropriate and in line with other frequently used mucosal repair options such as a nasoseptal flap. Our patients routinely get Unasyn or similar antibiotics intraoperatively as prophylaxis to cover respiratory flora, which has excellent oral flora coverage. A quick prep with chlorhexidine 0.12% oral solution may be utilized prior to graft harvest. The lateral tongue graft is then soaked in saline prior to placement and the muscle (rather than mucosal) side of the graft is placed over the ICA injury. We are not the first to report the use of soft tissue from the oral cavity for skull base repair. The facial artery buccinator flap and the facial artery musculomucosal flaps have previously been described as reconstructive options for skull base defects. ^{17 18} Previous authors have also recommended utilizing chlorhexidine to decrease oral cavity bacterial counts. ¹⁸ None of the patients described here experienced any new postoperative infections or wound healing difficulties.

The utility of tongue grafts has been described in several other scenarios, including palatal fistulae, buccal and mucosal lip defects, and other oral cavity defects. ^{19 20 21} This graft donor site benefits from low morbidity and ease of obtainment. Utilizing the techniques described in this manuscript can reduce cosmetic defects associated with an incision in the neck if extracting grafts from the SCM such as hypopigmentation, hypertrophic scarring, and keloid formation. It also has the potential to reduce postoperative pain/discomfort as well as nursing care. The oral tongue mucosa has notably rich vasculature and capillary beds/anastomoses which subsequently allows for expeditious and effective healing that is not consistently observed with skin. Additionally, there are almost no cosmetic deformities or morbidity with the extraction of such a graft as long as care is taken to obtain the graft from the lateral donor site, avoiding the tongue tip which is crucial for articulation. Integrating lateral tongue muscle graft into the management of ICA injuries should be encouraged. While it would be difficult to randomize or directly study the comparative effect of different methods of tamponade due to the acuity and rarity of the event of interest, in-vitro models suggest that muscle grafts are a superior form of management, which supports the consideration of tongue muscle flaps as an effective method for hemostasis.

Conclusion

The lateral tongue muscle graft appears to be an effective and an efficient method to manage ICA injuries during endoscopic sinus surgery. This source of graft has the advantage of being in the surgical field and is easily, quickly harvested with minimal donor site morbidity. It should be added to the repertoire of possible donor sites while dealing with catastrophic ICA bleeding.

Funding Statement

Funding J.H.T. is supported by NIH R21 AI142321 and NIH R01 AG065550. These funding organizations did not contribute to the design or conduct of this study; collection, management, analysis, or interpretation of the data; preparation, review, approval, or decision to submit this manuscript for publication. There are no relevant financial disclosures for any of the other authors.