AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
Available online at www.sciencedirect.com
ScienceDirect www.elsevier.com/locate/amjoto
Clinical pearls in endoscopic sinus surgery: Key steps in preventing and dealing with complications☆,☆☆ Jean Anderson Eloy, MD, FACS a, b, c,⁎, Peter F. Svider, MD a , Michael Setzen, MD, FACS d, e a
Department of Otolaryngology–Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA c Center for Skull Base and Pituitary Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA d Rhinology Section, North Shore University Hospital, Manhasset, NY, USA e Department of Otolaryngology, New York University School of Medicine, New York, NY, USA b
ARTI CLE I NFO
A BS TRACT
Article history:
Increasing prevalence of patients undergoing endoscopic sinus surgery (ESS) makes
Received 2 January 2014
understanding methods to preventing complications important to otolaryngologists. This commentary details clinical pearls and perioperative strategies that may minimize complications and increase preparedness for appropriate decision making in the event of a complication. Preoperative preparation is an important factor in preventing adverse events in ESS. This includes ensuring the presence of objective radiographic findings before pursuing operative management, both for patients' safety as well as medicolegal reasons, and providing adequate preoperative patient education. Appreciating variants in skull base and orbital wall anatomy through preoperative imaging is crucial for avoidance of intracranial and orbital complications. The importance of optimal visualization intraoperatively and the appropriate role of CT-guided imaging are also discussed. Finally, strategies for dealing with postoperative sequelae of more common complications are noted. This article represents a brief review for introductory sinus surgeons and is not meant as an all encompassing review. © 2014 Elsevier Inc. All rights reserved.
1.
Introduction
The increase in patients undergoing endoscopic sinus surgery (ESS) over the past two decades and accompanying technological innovations necessitate an understanding of inherent risks as well as approaches to prevent complications. Critical intracranial and orbital structures surrounding the paranasal sinuses make adverse events potentially devastating. Several straightforward precautions combined with sound perioperative strategies may prevent complications and ensure
preparedness for an appropriate course of action in the case of an unfortunate event, ultimately limiting medicolegal liability and improving patient safety.
2.
Preoperative considerations
Adequate preoperative evaluation is crucial for prevention of complications, as understanding variants in patient's sinonasal anatomy and the extent of disease is necessary to facilitate
☆
Financial disclosures: None. Conflicts of interest: M.S.: speaker for TEVA and MEDA on their Speakers Bureau (not related to the current subject). ⁎ Corresponding author at: Department of Otolaryngology–Head and Neck Surgery, Rutgers New Jersey Medical School, 90 Bergen St., Suite 8100, Newark, NJ 07103, USA. Tel.: + 1 973 972 4588; fax: +1 973 972 3767. E-mail address: [email protected] (J.A. Eloy). ☆☆
0196-0709/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjoto.2014.01.013
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
appropriate decision making. ESS should not be undertaken without radiographic evidence of disease or maximal medical management. If complications were to occur and a patient initiates litigation, it may be nearly impossible to justify the necessity of ESS in such a case. Indeed, the degree of pathology on imaging is the strongest predictive prognostic factor after ESS [1]. For symptomatic patients without radiographic evidence of disease, medical management alone may satisfy the goals of enhancing patient safety while minimizing liability. Utilizing the Lund–Mackay staging assists in CT interpretation in this regard, as a very low score (at or near 0) is less likely to gain maximal benefit from operative management [2]. Appreciating variants in skull base anatomy is essential to avoid intracranial complications [3]. Length of the lamina lateralis (Fig. 1A), categorized by Keros type [4], plays an important role in the preoperative review of CT imaging. A type 3 lamina lateralis has a depth of 8–16 mm. While this is found in a smaller percentage of the population, this skull base configuration is most often violated during ESS [5]. In contrast, shorter and smaller lamina lateralis, such as type 1, are less often breached. The majority of patients fall somewhere in between these two extremes, with a Keros type 2 that has a depth between 4 and 7 mm. Another critical aspect of evaluating skull base anatomy includes disease abutting the skull base. When this is noted on preoperative imaging, ESS surgeons can be more conser-
325
vative by avoiding complete skeletonization of the skull base [6]. This ensures that if there are skull base defects, direct and aggressive manipulation is kept to a minimum. Additionally, the slope (Fig. 1B) of the skull base and the presence of dehiscence (Fig. 1C) should be noted on preoperative imaging. Location of the ethmoidal arteries should be identified on the preoperative CT. Generally, the posterior ethmoidal artery is located intracranially. The anterior ethmoidal artery, however, may be found in the ethmoid sinus mesentery in 20%–40% of cases, and is typically adjacent to the superior oblique muscle (Fig. 1D) [7]. If transection is necessary, it is preferable to divide these arteries farther from the orbit to prevent retraction of the cut end of these vessels into the orbit which could lead to a retrobulbar hemorrhage. Dividing these arteries closer to the cribriform leaves a remnant vasculature that can be cauterized even in the case of partial retraction toward the orbit. Examination of the medial orbital wall anatomy is also important preoperatively. The location of the lacrimal sac and duct and the presence of visible dehiscence of the lamina papyracea should be noted. The relationship of the uncinate process to the medial orbital wall is important. If adequate space exists between the uncinate process and the medial orbital wall, the former can be dissected away using a sickle knife. If the uncinate process, however, is against the medial orbital wall, a frontal sinus probe may be used to gently peel it away from the orbit.
Fig. 1 – Factors to consider in evaluating skull base anatomy preoperatively. (A) Keros type 3 lamina lateralis (dotted line depicts skull base height). (B) Sagittal CT showing downward sloping of the skull base. (C) Left posterior frontal sinus table dehiscence (arrow). (D) Coronal CT indicating left anterior ethmoidal artery adjacent to the left superior oblique muscle (asterisk).
326
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
Sinus anatomy variants are important to recognize during review of preoperative imaging. These include variant ethmoid cells such as Haller cells, Onodi cells, and agger nasi cells. Haller cells are found below the orbital floor (Fig. 2A) and should be noted to avoid intraorbital penetration. Agger nasi cells are anteriorly located ethmoid cells (Fig. 2B) and may be viewed anterior to the middle turbinate on coronal CT imaging (Fig. 2C) [8,9]. Agger nasi cells are important in deciding optimal approach in surgery involving the frontal recess [8]. Onodi cells are posteriorly located ethmoid air cells, lying directly superior to the sphenoid sinus (Fig. 2D). The optic nerve and carotid arteries may be located within or nearby Onodi cells; therefore, identifying whether they are present on preoperative CT is crucial in avoiding serious sequelae associated with injury of these structures [10,11]. Thorough discussion with patients of informed consent detailing risks, benefits, and alternatives should be undertaken prior to ESS. This includes meticulous discussion of potential intracranial and intraorbital injuries. Recent analysis of litigation related to iatrogenic orbital injury [12] and cerebrospinal fluid (CSF) leak [13] found that inadequate informed consents played a significant role in initiation of litigation. Factors such as orbital injury, CSF leak, bleeding, infection, and anosmia and hyposmia, should be discussed with patients [13,14], and documented in writing on informed consent forms and potentially on an ESS preoperative and postoperative instruction sheets to facilitate patient comprehension.
3.
Intraoperative approach
Although adequate preoperative preparation is paramount, there are several intraoperative considerations that should be noted. Preoperative CT scans should be available in the operating room for review. Adequate intraoperative visualization is important, given the association between limited visualization and complications in ESS. Proper bleeding control is necessary to optimize the surgical field. Achieving this goal begins preoperatively with a comprehensive history and providing patients with a written list of both prescription and non-prescription medications to avoid. Corticosteroid and antibiotic administration may be considered for patients with sinonasal polyps and active infections respectively [15–17]. Intraoperatively, it is important to allow adequate time for the full effects of vasoconstrictive agents. Optimal control of bleeding includes infiltration of the vasoconstrictive agents in multiple key sites, including the uncinate process, the anterior– superior attachment of the middle turbinate, the tail of the middle turbinate, the sphenopalatine region, and the nasal septum. Greater palatine canal (GPC) infiltration may be considered in patients with polyposis obstructing transnasal access to the previously stated injection sites [18]. GPC infiltration is effectively achieved using a needle bent 25 mm from the tip at a 45-degree angle [19]. In case of bleeding near the skull base or medial orbital wall, bipolar cauterization is preferable to unipolar devices. Powered tools such as microdebriders and
Fig. 2 – (A) Coronal CT scan showing Haller cell (arrow). Sagittal (B) and coronal (C) CT scans depicting an agger nasi cell (arrows). (D) Coronal CT of a mucocele from an Onodi cell with skull base and orbital dehiscence.
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
drills should be kept away from vital structures and due diligence should be used regarding the speed of these devices. The increase availability of image guidance systems over the past decade has resulted in a subsequent increase in their intraoperative use. Although helpful, image guidance is a complement, rather than a substitute for knowledge of sinonasal anatomy. The American Academy of Otolaryngology–Head and Neck Surgery has endorsed image guidance use in select cases, particularly patients with complex anatomy. Calibrating theses systems may add to surgical time, but they can be useful in difficult anatomy [20]. Nonetheless, no evidencebased data exist that definitively prove a decreased incidence in surgical complications or improvement in surgical outcomes with image guidance use [21,22].
4. Management of postoperative complications Retrobulbar hemorrhage occurs from avulsion of ethmoidal arteries that subsequently retract into the orbit. Ophthalmologic consultation should be sought immediately, as this may improve patient care and help with potential malpractice litigation [12]. This complication may present with abrupt orbital swelling over a span of minutes, extreme pain, diplopia, proptosis, and ecchymosis [7,23]. Concerns for orbital compression syndrome should be noted if tonometric pressure is within 20 mm Hg of the mean arterial pressure, as this requires urgent management [24]. Treatment includes head elevation, removal of nasal packing, control of epistaxis, and various maneuvers to decrease intraocular pressure and inflammation such as systemic corticosteroids, topical vasoconstrictors, mannitol, and acetazolamide. If conservative management fails, timely canthotomy and/or cantholysis and endoscopic medial orbital wall decompression should be performed. External orbital decompression should be reserved for failure of the aforementioned interventions. Occasionally, venous orbital hemorrhage occurs following violation of the lamina papyracea, and has a more subacute presentation that includes orbital swelling, pain, and visual loss over hours in comparison to minutes seen in arterial causes. Extraocular muscle injury and resultant dysmotility usually occur from direct muscle injury, muscle entrapment, orbital fat prolapse, or orbital fibrosis [25]. In the absence of entrapment or direct muscle injury, conservative measures such as observation are sufficient [26]. However, a visible medial orbital wall defect and medial rectus muscle entrapment necessitate exploration and debridement of fractures, and possible repair with an implant. For direct muscle transections, reattachment is necessary. Although early intervention is recommended, long-term injury can be improved with rectus muscle transposition, although patients should expect persistent functional impairment [27]. Orbital emphysema represents another potential injury, which usually occurs from fracture of the lamina papyracea and subsequent nose blowing, leading to periorbital ecchymosis [28]. Treatment of this condition includes ophthalmologic evaluation, antibiotics, and avoidance of nose blowing. Another potential complication of ESS is injury to the nasolacrimal system. This usually occurs during maxillary
327
antrostomy, though it typically does not result in epiphora. Treatment may be conservative, with corticosteroids, antibiotics, and reassurance postoperatively. If the patient does develop long-term epiphora, dacryocystorhinotomy may be required. Direct optic nerve damage is rare following ESS. When it occurs, it is usually during sphenoid sinusotomy; the presence of Onodi cells may contribute to the occurrence of this injury [10]. Although there is no proven treatment, a trial of high-dose corticosteroids may be attempted. Ophthalmologic consultation should be obtained if this injury is suspected. For optic nerve injury resulting from direct compression by a bony fragment, decompression has been helpful if performed in a timely fashion. Intracranial complications from ESS may have serious sequelae. Parenchymal brain injury and carotid artery injury may occur, but are less common than iatrogenic CSF leak [29]. The latter typically occurs in the setting of excessive intraoperative bleeding and is present in 0.5% of surgical cases. CSF leak usually occurs at the area of the lamina lateralis, as previously mentioned, but can occur anywhere along the skull base. Treatment involves neurosurgical consultation, and repair of the defect. A two-layered closure may be helpful, using an acellular dermal allograft intracranially to plug the defect, and a free intranasal mucosal graft harvested from the septum or middle turbinate. Demucosalization of the skull base around the defect is necessary to prevent intracranial entrapment of mucosa and later development of intracranial mucocele [30].
5.
Conclusions
Preoperative evaluation and preparation are paramount in preventing complications in ESS. Clear indications and the presence of objective radiographic findings should be documented before operative management, both for patient safety and for legal protection. Attention to patient education and adequate informed consent may decrease liability should complications arise. Intraoperatively, optimal visualization may decrease complications. Although not a substitute for careful planning and knowledge of sinonasal anatomy, image guidance is helpful in select cases. In case of orbital and intracranial complications, timely ophthalmologic and neurosurgical consultation may minimize adverse outcomes and decrease liability.
REFERENCES
[1] Kennedy DW. Prognostic factors, outcomes and staging in ethmoid sinus surgery. Laryngoscope 1992;102:1–18. [2] Ashraf N, Bhattacharyya N. Determination of the “incidental” Lund score for the staging of chronic rhinosinusitis. Otolaryngol Head Neck Surg 2001;125:483–6. [3] Stankiewicz JA, Chow JM. The low skull base—is it important? Curr Opin Otolaryngol Head Neck Surg 2005;13:19–21. [4] Keros P. On the practical value of differences in the level of the lamina cribrosa of the ethmoid. Z Laryngol Rhinol Otol 1962;41:809–13. [5] Gauba V, Saleh GM, Dua G, et al. Radiological classification of anterior skull base anatomy prior to performing medial orbital wall decompression. Orbit 2006;25:93–6.
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[6] DelGaudio JM, Mathison CC, Hudgins PA. Preoperative disease severity at sites of subsequent skull base defects after endoscopic sinus surgery. Am J Rhinol 2008;22:321–4. [7] Han JK, Higgins TS. Management of orbital complications in endoscopic sinus surgery. Curr Opin Otolaryngol Head Neck Surg 2010;18:32–6. [8] Wormald PJ. The agger nasi cell: the key to understanding the anatomy of the frontal recess. Otolaryngol Head Neck Surg 2003;129:497–507. [9] Bolger WE, Butzin CA, Parsons DS. Paranasal sinus bony anatomic variations and mucosal abnormalities: CT analysis for endoscopic sinus surgery. Laryngoscope 1991;101:56–64. [10] Tomovic S, Esmaeili A, Chan NJ, et al. High-resolution computed tomography analysis of the prevalence of onodi cells. Laryngoscope 2012;122:1470–3. [11] Tomovic S, Esmaeili A, Chan NJ, et al. High-resolution computed tomography analysis of variations of the sphenoid sinus. J Neurol Surg B 2013;74:082–90. [12] Svider PF, Kovalerchik O, Mauro AC, et al. Legal liability in iatrogenic orbital injury. Laryngoscope 2013;123:2099–103. [13] Kovalerchik O, Mady LJ, Svider PF, et al. Physician accountability in iatrogenic cerebrospinal fluid leak litigation. Int Forum Allergy Rhinol 2013;3:722–5. [14] Wolf JS, Malekzadeh S, Berry JA, et al. Informed consent in functional endoscopic sinus surgery. Laryngoscope 2002;112: 774–8. [15] Albu S, Gocea A, Mitre I. Preoperative treatment with topical corticoids and bleeding during primary endoscopic sinus surgery. Otolaryngol Head Neck Surg 2010;143:573–8. [16] Wright ED, Agrawal S. Impact of perioperative systemic steroids on surgical outcomes in patients with chronic rhinosinusitis with polyposis: evaluation with the novel Perioperative Sinus Endoscopy (POSE) scoring system. Laryngoscope 2007;117:1–28. [17] Sieskiewicz A, Olszewska E, Rogowski M, et al. Preoperative corticosteroid oral therapy and intraoperative bleeding during functional endoscopic sinus surgery in patients with severe nasal polyposis: a preliminary investigation. Ann Otol Rhinol Laryngol 2006;115:490–4.
[18] Eloy JA, Kovalerchik O, Bublik M, et al. Effect of greater palatine canal injection on estimated blood loss during endoscopic sinus surgery. Am J Otolaryngol 2014;35:1–4. [19] Douglas R, Wormald PJ. Pterygopalatine fossa infiltration through the greater palatine foramen: where to bend the needle. Laryngoscope 2006;116:1255–7. [20] Smith TL, Stewart MG, Orlandi RR, et al. Indications for image-guided sinus surgery: the current evidence. Am J Rhinol 2007;21:80–3. [21] Ramakrishnan VR, Orlandi RR, Citardi MJ, et al. The use of image-guided surgery in endoscopic sinus surgery: an evidence-based review with recommendations. Int Forum Allergy Rhinol 2013;3:236–41. [22] Eloy JA, Svider PF, D'Aguillo CM, et al. Image-guidance in endoscopic sinus surgery: is it associated with decreased medicolegal liability? Int Forum Allergy Rhinol 2013;3:980–5. [23] Han JK, Caughey RJ, Gross CW, et al. Management of retrobulbar hematoma. Am J Rhinol 2008;22:522–4. [24] Hatton MP, Rubin PA. Management of orbital compartment syndrome. Arch Ophthalmol 2007;125:433–4 [author reply 434]. [25] Thacker NM, Velez FG, Demer JL, et al. Extraocular muscle damage associated with endoscopic sinus surgery: an ophthalmology perspective. Am J Rhinol 2005;19:400–5. [26] Ela-Dalman N, Velez FG, Rosenbaum AL. Importance of sagittal orbital imaging in evaluating extraocular muscle trauma following endoscopic sinus surgery. Br J Ophthalmol 2006;90:682–5. [27] Thacker NM, Velez FG, Demer JL, et al. Strabismic complications following endoscopic sinus surgery: diagnosis and surgical management. J AAPOS 2004;8:488–94. [28] Rubinstein A, Riddell CE, Akram I, et al. Orbital emphysema leading to blindness following routine functional endoscopic sinus surgery. Arch Ophthalmol 2005;123:1452. [29] Ramakrishnan VR, Kingdom TT, Nayak JV, et al. Nationwide incidence of major complications in endoscopic sinus surgery. Int Forum Allergy Rhinol 2012;2:34–9. [30] Eloy JA, Fatterpekar GM, Bederson JB, et al. Intracranial mucocele: an unusual complication of cerebrospinal fluid leakage repair with middle turbinate mucosal graft. Otolaryngol Head Neck Surg 2007;137:350–2.
Available online at www.sciencedirect.com
ScienceDirect www.elsevier.com/locate/amjoto
Clinical pearls in endoscopic sinus surgery: Key steps in preventing and dealing with complications☆,☆☆ Jean Anderson Eloy, MD, FACS a, b, c,⁎, Peter F. Svider, MD a , Michael Setzen, MD, FACS d, e a
Department of Otolaryngology–Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA c Center for Skull Base and Pituitary Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA d Rhinology Section, North Shore University Hospital, Manhasset, NY, USA e Department of Otolaryngology, New York University School of Medicine, New York, NY, USA b
ARTI CLE I NFO
A BS TRACT
Article history:
Increasing prevalence of patients undergoing endoscopic sinus surgery (ESS) makes
Received 2 January 2014
understanding methods to preventing complications important to otolaryngologists. This commentary details clinical pearls and perioperative strategies that may minimize complications and increase preparedness for appropriate decision making in the event of a complication. Preoperative preparation is an important factor in preventing adverse events in ESS. This includes ensuring the presence of objective radiographic findings before pursuing operative management, both for patients' safety as well as medicolegal reasons, and providing adequate preoperative patient education. Appreciating variants in skull base and orbital wall anatomy through preoperative imaging is crucial for avoidance of intracranial and orbital complications. The importance of optimal visualization intraoperatively and the appropriate role of CT-guided imaging are also discussed. Finally, strategies for dealing with postoperative sequelae of more common complications are noted. This article represents a brief review for introductory sinus surgeons and is not meant as an all encompassing review. © 2014 Elsevier Inc. All rights reserved.
1.
Introduction
The increase in patients undergoing endoscopic sinus surgery (ESS) over the past two decades and accompanying technological innovations necessitate an understanding of inherent risks as well as approaches to prevent complications. Critical intracranial and orbital structures surrounding the paranasal sinuses make adverse events potentially devastating. Several straightforward precautions combined with sound perioperative strategies may prevent complications and ensure
preparedness for an appropriate course of action in the case of an unfortunate event, ultimately limiting medicolegal liability and improving patient safety.
2.
Preoperative considerations
Adequate preoperative evaluation is crucial for prevention of complications, as understanding variants in patient's sinonasal anatomy and the extent of disease is necessary to facilitate
☆
Financial disclosures: None. Conflicts of interest: M.S.: speaker for TEVA and MEDA on their Speakers Bureau (not related to the current subject). ⁎ Corresponding author at: Department of Otolaryngology–Head and Neck Surgery, Rutgers New Jersey Medical School, 90 Bergen St., Suite 8100, Newark, NJ 07103, USA. Tel.: + 1 973 972 4588; fax: +1 973 972 3767. E-mail address: [email protected] (J.A. Eloy). ☆☆
0196-0709/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjoto.2014.01.013
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
appropriate decision making. ESS should not be undertaken without radiographic evidence of disease or maximal medical management. If complications were to occur and a patient initiates litigation, it may be nearly impossible to justify the necessity of ESS in such a case. Indeed, the degree of pathology on imaging is the strongest predictive prognostic factor after ESS [1]. For symptomatic patients without radiographic evidence of disease, medical management alone may satisfy the goals of enhancing patient safety while minimizing liability. Utilizing the Lund–Mackay staging assists in CT interpretation in this regard, as a very low score (at or near 0) is less likely to gain maximal benefit from operative management [2]. Appreciating variants in skull base anatomy is essential to avoid intracranial complications [3]. Length of the lamina lateralis (Fig. 1A), categorized by Keros type [4], plays an important role in the preoperative review of CT imaging. A type 3 lamina lateralis has a depth of 8–16 mm. While this is found in a smaller percentage of the population, this skull base configuration is most often violated during ESS [5]. In contrast, shorter and smaller lamina lateralis, such as type 1, are less often breached. The majority of patients fall somewhere in between these two extremes, with a Keros type 2 that has a depth between 4 and 7 mm. Another critical aspect of evaluating skull base anatomy includes disease abutting the skull base. When this is noted on preoperative imaging, ESS surgeons can be more conser-
325
vative by avoiding complete skeletonization of the skull base [6]. This ensures that if there are skull base defects, direct and aggressive manipulation is kept to a minimum. Additionally, the slope (Fig. 1B) of the skull base and the presence of dehiscence (Fig. 1C) should be noted on preoperative imaging. Location of the ethmoidal arteries should be identified on the preoperative CT. Generally, the posterior ethmoidal artery is located intracranially. The anterior ethmoidal artery, however, may be found in the ethmoid sinus mesentery in 20%–40% of cases, and is typically adjacent to the superior oblique muscle (Fig. 1D) [7]. If transection is necessary, it is preferable to divide these arteries farther from the orbit to prevent retraction of the cut end of these vessels into the orbit which could lead to a retrobulbar hemorrhage. Dividing these arteries closer to the cribriform leaves a remnant vasculature that can be cauterized even in the case of partial retraction toward the orbit. Examination of the medial orbital wall anatomy is also important preoperatively. The location of the lacrimal sac and duct and the presence of visible dehiscence of the lamina papyracea should be noted. The relationship of the uncinate process to the medial orbital wall is important. If adequate space exists between the uncinate process and the medial orbital wall, the former can be dissected away using a sickle knife. If the uncinate process, however, is against the medial orbital wall, a frontal sinus probe may be used to gently peel it away from the orbit.
Fig. 1 – Factors to consider in evaluating skull base anatomy preoperatively. (A) Keros type 3 lamina lateralis (dotted line depicts skull base height). (B) Sagittal CT showing downward sloping of the skull base. (C) Left posterior frontal sinus table dehiscence (arrow). (D) Coronal CT indicating left anterior ethmoidal artery adjacent to the left superior oblique muscle (asterisk).
326
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
Sinus anatomy variants are important to recognize during review of preoperative imaging. These include variant ethmoid cells such as Haller cells, Onodi cells, and agger nasi cells. Haller cells are found below the orbital floor (Fig. 2A) and should be noted to avoid intraorbital penetration. Agger nasi cells are anteriorly located ethmoid cells (Fig. 2B) and may be viewed anterior to the middle turbinate on coronal CT imaging (Fig. 2C) [8,9]. Agger nasi cells are important in deciding optimal approach in surgery involving the frontal recess [8]. Onodi cells are posteriorly located ethmoid air cells, lying directly superior to the sphenoid sinus (Fig. 2D). The optic nerve and carotid arteries may be located within or nearby Onodi cells; therefore, identifying whether they are present on preoperative CT is crucial in avoiding serious sequelae associated with injury of these structures [10,11]. Thorough discussion with patients of informed consent detailing risks, benefits, and alternatives should be undertaken prior to ESS. This includes meticulous discussion of potential intracranial and intraorbital injuries. Recent analysis of litigation related to iatrogenic orbital injury [12] and cerebrospinal fluid (CSF) leak [13] found that inadequate informed consents played a significant role in initiation of litigation. Factors such as orbital injury, CSF leak, bleeding, infection, and anosmia and hyposmia, should be discussed with patients [13,14], and documented in writing on informed consent forms and potentially on an ESS preoperative and postoperative instruction sheets to facilitate patient comprehension.
3.
Intraoperative approach
Although adequate preoperative preparation is paramount, there are several intraoperative considerations that should be noted. Preoperative CT scans should be available in the operating room for review. Adequate intraoperative visualization is important, given the association between limited visualization and complications in ESS. Proper bleeding control is necessary to optimize the surgical field. Achieving this goal begins preoperatively with a comprehensive history and providing patients with a written list of both prescription and non-prescription medications to avoid. Corticosteroid and antibiotic administration may be considered for patients with sinonasal polyps and active infections respectively [15–17]. Intraoperatively, it is important to allow adequate time for the full effects of vasoconstrictive agents. Optimal control of bleeding includes infiltration of the vasoconstrictive agents in multiple key sites, including the uncinate process, the anterior– superior attachment of the middle turbinate, the tail of the middle turbinate, the sphenopalatine region, and the nasal septum. Greater palatine canal (GPC) infiltration may be considered in patients with polyposis obstructing transnasal access to the previously stated injection sites [18]. GPC infiltration is effectively achieved using a needle bent 25 mm from the tip at a 45-degree angle [19]. In case of bleeding near the skull base or medial orbital wall, bipolar cauterization is preferable to unipolar devices. Powered tools such as microdebriders and
Fig. 2 – (A) Coronal CT scan showing Haller cell (arrow). Sagittal (B) and coronal (C) CT scans depicting an agger nasi cell (arrows). (D) Coronal CT of a mucocele from an Onodi cell with skull base and orbital dehiscence.
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
drills should be kept away from vital structures and due diligence should be used regarding the speed of these devices. The increase availability of image guidance systems over the past decade has resulted in a subsequent increase in their intraoperative use. Although helpful, image guidance is a complement, rather than a substitute for knowledge of sinonasal anatomy. The American Academy of Otolaryngology–Head and Neck Surgery has endorsed image guidance use in select cases, particularly patients with complex anatomy. Calibrating theses systems may add to surgical time, but they can be useful in difficult anatomy [20]. Nonetheless, no evidencebased data exist that definitively prove a decreased incidence in surgical complications or improvement in surgical outcomes with image guidance use [21,22].
4. Management of postoperative complications Retrobulbar hemorrhage occurs from avulsion of ethmoidal arteries that subsequently retract into the orbit. Ophthalmologic consultation should be sought immediately, as this may improve patient care and help with potential malpractice litigation [12]. This complication may present with abrupt orbital swelling over a span of minutes, extreme pain, diplopia, proptosis, and ecchymosis [7,23]. Concerns for orbital compression syndrome should be noted if tonometric pressure is within 20 mm Hg of the mean arterial pressure, as this requires urgent management [24]. Treatment includes head elevation, removal of nasal packing, control of epistaxis, and various maneuvers to decrease intraocular pressure and inflammation such as systemic corticosteroids, topical vasoconstrictors, mannitol, and acetazolamide. If conservative management fails, timely canthotomy and/or cantholysis and endoscopic medial orbital wall decompression should be performed. External orbital decompression should be reserved for failure of the aforementioned interventions. Occasionally, venous orbital hemorrhage occurs following violation of the lamina papyracea, and has a more subacute presentation that includes orbital swelling, pain, and visual loss over hours in comparison to minutes seen in arterial causes. Extraocular muscle injury and resultant dysmotility usually occur from direct muscle injury, muscle entrapment, orbital fat prolapse, or orbital fibrosis [25]. In the absence of entrapment or direct muscle injury, conservative measures such as observation are sufficient [26]. However, a visible medial orbital wall defect and medial rectus muscle entrapment necessitate exploration and debridement of fractures, and possible repair with an implant. For direct muscle transections, reattachment is necessary. Although early intervention is recommended, long-term injury can be improved with rectus muscle transposition, although patients should expect persistent functional impairment [27]. Orbital emphysema represents another potential injury, which usually occurs from fracture of the lamina papyracea and subsequent nose blowing, leading to periorbital ecchymosis [28]. Treatment of this condition includes ophthalmologic evaluation, antibiotics, and avoidance of nose blowing. Another potential complication of ESS is injury to the nasolacrimal system. This usually occurs during maxillary
327
antrostomy, though it typically does not result in epiphora. Treatment may be conservative, with corticosteroids, antibiotics, and reassurance postoperatively. If the patient does develop long-term epiphora, dacryocystorhinotomy may be required. Direct optic nerve damage is rare following ESS. When it occurs, it is usually during sphenoid sinusotomy; the presence of Onodi cells may contribute to the occurrence of this injury [10]. Although there is no proven treatment, a trial of high-dose corticosteroids may be attempted. Ophthalmologic consultation should be obtained if this injury is suspected. For optic nerve injury resulting from direct compression by a bony fragment, decompression has been helpful if performed in a timely fashion. Intracranial complications from ESS may have serious sequelae. Parenchymal brain injury and carotid artery injury may occur, but are less common than iatrogenic CSF leak [29]. The latter typically occurs in the setting of excessive intraoperative bleeding and is present in 0.5% of surgical cases. CSF leak usually occurs at the area of the lamina lateralis, as previously mentioned, but can occur anywhere along the skull base. Treatment involves neurosurgical consultation, and repair of the defect. A two-layered closure may be helpful, using an acellular dermal allograft intracranially to plug the defect, and a free intranasal mucosal graft harvested from the septum or middle turbinate. Demucosalization of the skull base around the defect is necessary to prevent intracranial entrapment of mucosa and later development of intracranial mucocele [30].
5.
Conclusions
Preoperative evaluation and preparation are paramount in preventing complications in ESS. Clear indications and the presence of objective radiographic findings should be documented before operative management, both for patient safety and for legal protection. Attention to patient education and adequate informed consent may decrease liability should complications arise. Intraoperatively, optimal visualization may decrease complications. Although not a substitute for careful planning and knowledge of sinonasal anatomy, image guidance is helpful in select cases. In case of orbital and intracranial complications, timely ophthalmologic and neurosurgical consultation may minimize adverse outcomes and decrease liability.
REFERENCES
[1] Kennedy DW. Prognostic factors, outcomes and staging in ethmoid sinus surgery. Laryngoscope 1992;102:1–18. [2] Ashraf N, Bhattacharyya N. Determination of the “incidental” Lund score for the staging of chronic rhinosinusitis. Otolaryngol Head Neck Surg 2001;125:483–6. [3] Stankiewicz JA, Chow JM. The low skull base—is it important? Curr Opin Otolaryngol Head Neck Surg 2005;13:19–21. [4] Keros P. On the practical value of differences in the level of the lamina cribrosa of the ethmoid. Z Laryngol Rhinol Otol 1962;41:809–13. [5] Gauba V, Saleh GM, Dua G, et al. Radiological classification of anterior skull base anatomy prior to performing medial orbital wall decompression. Orbit 2006;25:93–6.
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AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 32 4–3 2 8
[6] DelGaudio JM, Mathison CC, Hudgins PA. Preoperative disease severity at sites of subsequent skull base defects after endoscopic sinus surgery. Am J Rhinol 2008;22:321–4. [7] Han JK, Higgins TS. Management of orbital complications in endoscopic sinus surgery. Curr Opin Otolaryngol Head Neck Surg 2010;18:32–6. [8] Wormald PJ. The agger nasi cell: the key to understanding the anatomy of the frontal recess. Otolaryngol Head Neck Surg 2003;129:497–507. [9] Bolger WE, Butzin CA, Parsons DS. Paranasal sinus bony anatomic variations and mucosal abnormalities: CT analysis for endoscopic sinus surgery. Laryngoscope 1991;101:56–64. [10] Tomovic S, Esmaeili A, Chan NJ, et al. High-resolution computed tomography analysis of the prevalence of onodi cells. Laryngoscope 2012;122:1470–3. [11] Tomovic S, Esmaeili A, Chan NJ, et al. High-resolution computed tomography analysis of variations of the sphenoid sinus. J Neurol Surg B 2013;74:082–90. [12] Svider PF, Kovalerchik O, Mauro AC, et al. Legal liability in iatrogenic orbital injury. Laryngoscope 2013;123:2099–103. [13] Kovalerchik O, Mady LJ, Svider PF, et al. Physician accountability in iatrogenic cerebrospinal fluid leak litigation. Int Forum Allergy Rhinol 2013;3:722–5. [14] Wolf JS, Malekzadeh S, Berry JA, et al. Informed consent in functional endoscopic sinus surgery. Laryngoscope 2002;112: 774–8. [15] Albu S, Gocea A, Mitre I. Preoperative treatment with topical corticoids and bleeding during primary endoscopic sinus surgery. Otolaryngol Head Neck Surg 2010;143:573–8. [16] Wright ED, Agrawal S. Impact of perioperative systemic steroids on surgical outcomes in patients with chronic rhinosinusitis with polyposis: evaluation with the novel Perioperative Sinus Endoscopy (POSE) scoring system. Laryngoscope 2007;117:1–28. [17] Sieskiewicz A, Olszewska E, Rogowski M, et al. Preoperative corticosteroid oral therapy and intraoperative bleeding during functional endoscopic sinus surgery in patients with severe nasal polyposis: a preliminary investigation. Ann Otol Rhinol Laryngol 2006;115:490–4.
[18] Eloy JA, Kovalerchik O, Bublik M, et al. Effect of greater palatine canal injection on estimated blood loss during endoscopic sinus surgery. Am J Otolaryngol 2014;35:1–4. [19] Douglas R, Wormald PJ. Pterygopalatine fossa infiltration through the greater palatine foramen: where to bend the needle. Laryngoscope 2006;116:1255–7. [20] Smith TL, Stewart MG, Orlandi RR, et al. Indications for image-guided sinus surgery: the current evidence. Am J Rhinol 2007;21:80–3. [21] Ramakrishnan VR, Orlandi RR, Citardi MJ, et al. The use of image-guided surgery in endoscopic sinus surgery: an evidence-based review with recommendations. Int Forum Allergy Rhinol 2013;3:236–41. [22] Eloy JA, Svider PF, D'Aguillo CM, et al. Image-guidance in endoscopic sinus surgery: is it associated with decreased medicolegal liability? Int Forum Allergy Rhinol 2013;3:980–5. [23] Han JK, Caughey RJ, Gross CW, et al. Management of retrobulbar hematoma. Am J Rhinol 2008;22:522–4. [24] Hatton MP, Rubin PA. Management of orbital compartment syndrome. Arch Ophthalmol 2007;125:433–4 [author reply 434]. [25] Thacker NM, Velez FG, Demer JL, et al. Extraocular muscle damage associated with endoscopic sinus surgery: an ophthalmology perspective. Am J Rhinol 2005;19:400–5. [26] Ela-Dalman N, Velez FG, Rosenbaum AL. Importance of sagittal orbital imaging in evaluating extraocular muscle trauma following endoscopic sinus surgery. Br J Ophthalmol 2006;90:682–5. [27] Thacker NM, Velez FG, Demer JL, et al. Strabismic complications following endoscopic sinus surgery: diagnosis and surgical management. J AAPOS 2004;8:488–94. [28] Rubinstein A, Riddell CE, Akram I, et al. Orbital emphysema leading to blindness following routine functional endoscopic sinus surgery. Arch Ophthalmol 2005;123:1452. [29] Ramakrishnan VR, Kingdom TT, Nayak JV, et al. Nationwide incidence of major complications in endoscopic sinus surgery. Int Forum Allergy Rhinol 2012;2:34–9. [30] Eloy JA, Fatterpekar GM, Bederson JB, et al. Intracranial mucocele: an unusual complication of cerebrospinal fluid leakage repair with middle turbinate mucosal graft. Otolaryngol Head Neck Surg 2007;137:350–2.
