Ophthalmic complications of endoscopic sinus surgery

Nontraumatic oculomotor nerve palsy following endoscopic sinus surgery

The proximity of the paranasal sinuses to the orbit and its contents increases the chances of injuries during endoscopic sinus surgery (ESS). We present an extremely rare case of transient oculomotor nerve palsy with no direct injury following ESS, which has never been reported in the literature. The proper clinical approach and medical management are also discussed in this case report.

Recovery From Visual Loss After Endoscopic Endonasal Decompression of Iatrogenic Orbital Abscess

Orbital complications are the second most common complications of endoscopic sinus surgery (ESS), and orbital hematoma is the most frequent orbital complication. An orbital abscess is usually associated with rhinosinusitis, and a few cases of orbital abscesses occurring after orbital trauma have been reported. However, orbital abscess occurring after ESS is rare. Herein, we present a case of a right orbital abscess that developed after bilateral ESS, performed at an outside facility, and decreased vision in the right eye to light perception only. The visual loss persisted for 3 days, after which the patient was referred to our hospital for urgent management. The cause of abscess formation might have been an infected stagnant orbital venous hematoma that occurred as a complication of ESS. A defect in the right lamina papyracea and emphysema were confirmed on computed tomography. Orbital symptoms started immediately after ESS, and vision deteriorated to light perception only and lasted for 3 days, which was considered a high-grade risk factor for irreversible blindness by the ophthalmology team. Urgent endoscopic endonasal orbital decompression was performed to drain the orbital abscess, and maximal medical treatment was initiated, which included intravenous corticosteroids, intravenous broad-spectrum antibiotics, topical intranasal corticosteroids, irrigation, and topical antibiotic eye drops. Close follow-up assessments were performed by the infectious diseases team, and the ophthalmology team performed frequent orbital assessments. The patient recovered from blindness, which was an unexpected outcome.

A Preoperative Imaging Evaluation to Avoid Orbital Complications in Functional Endoscopic Sinus Surgery

Functional endoscopic sinus surgery has become popular worldwide. However, serious complications have been reported with it. A preoperative imaging evaluation is thus essential to avoid complications. The authors compared 0.5 mm slice computed tomography (CT) images reconstructed from sinus CT data with conventional 2 mm slice CT images. The authors evaluated patients who underwent endoscopic surgery. Data regarding age, sex, history of craniofacial trauma, diagnosis, operative procedure, and CT findings of eligible patients were extracted from medical records and retrospectively reviewed. One hundred twelve patients underwent endoscopic surgery during the study period. Six patients (5.4%) had orbital blowout fractures, and half of them could only be identified by 0.5 mm slice CT images. The authors presented the usefulness of 0.5 mm slice CT images in the preoperative imaging evaluation of functional endoscopic sinus surgery. Surgeons should also recognize that a small number of patients have "stealth" (asymptomatic and unrecognized) blowout fractures.

Blindness Following Endoscopic Excision of Acinic Cell Carcinoma of Sphenoid Sinus: A Case Report

Acinic cell carcinoma (A.C.C.) is a low-grade malignancy involving salivary glands. A.C.C. accounts for only 1-4% of all sinonasal malignancies. We report the case of a 45-year-old female who presented with A.C.C. of paranasal sinus who developed loss of vision after Endoscopic sinus surgery (E.S.S.). Blindness, though rare, is a devastating complication of E.S.S. In this report, the rare occurrence of a papillary cystic variant of A.C.C. in the sphenoid sinus is reported. The causes that may lead to blindness during E.S.S. are analyzed in the absence of direct neural trauma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03190-2.

Simplification of the complex: Successful management of large-angle exodeviation after endoscopic sinus surgery

PURPOSE

To report the clinical characteristics and successful management of large-angle exodeviation due to medial rectus muscle (MR) transection incurred during endoscopic sinus surgery (ESS).

METHODS

The medical records of 5 consecutive inpatients with MR complete transection following ESS resulting in large-angle paralytic exodeviation between November 2014 and June 2021 were reviewed. The type of muscle injury, clinical characteristics, surgical procedure and dosage, and long-term outcomes were evaluated.

RESULTS

All 5 patients manifested exodeviations of 72 PD to >133 PD with no adduction capacity (graded -4); all of them had proven orbital trauma and complete MR transection with a ≥20 mm distal (globe attached) stump based on CT scans and/or MRI imaging. They underwent a supra-maximal recession (10-12 mm) of the lateral rectus and resection (10-15 mm) of the medial rectus on the affected eye. At least 1 year (1 to 5 years) following the corrective surgery, the patients still maintained orthophoria or had a small angle of exotropia (≤ 8 PD) in primary gaze with successful fusion, and 3 of them (Case 3, 4, and 5) exhibited a certain degree of stereopsis. In addition, appreciable adduction occurred (graded -1 to -3).

CONCLUSIONS

A supra-maximal recession/resection shows favorable outcomes in patients with proven complete transection MR with a ≥20 mm distal (globe attached) stump. It can help to achieve good ocular alignment and even yield improvements in adduction over time.

A review of the revisions and complications management procedure in sinus surgery

One of the most standard and least invasive surgical procedures that could be applied mostly for the treatment of inflammation of the paranasal sinuses is endonasal endoscopic sinus surgery. The main objective of this study is to assess the available strategies for avoiding, diagnosis and also dealing with various kinds of potential complications of sinus disorders as well as the symptoms which specify the need for revision endoscopic sinus surgery mainly for the treatment of chronic rhinosinusitis. Based on the objectives of this study, the studies were categorized within four main groups; sinus disorders, diagnosis, management, and treatment. In this regard, wide research has been done in various scientific databases of PubMed, EMBASE, Europe PMC, HubMed, MEDLINE, Scientific Information Database (SID) and Google Scholar. From a total of 315 founded records, the final number of 91 records were reviewed. The rate of complication associated with endoscopic sinus surgery is not much and the improvement of surgical technology and experience could decrease its side effects. Performing immediate extensive surgery among patients who have inflammatory sinonasal disease could modify long-term consequences. Applying endoscopic sinus surgery could yield the most appropriate positive outcomes. For achieving the most suitable surgical consequences, the surgeon should be adequately qualified in diagnosis and facing with any possible complications during the operation in addition to cases with complex and revision problems.

[Retrobulbar hematoma in endoscopic endonasal dacryocystorhinostomy]

Recently, an increase in the number of operations on the lacrimal ducts performed by otorhinolaryngologists has been noted throughout the world. During these operations, intra- and postoperative complications may develop, which require the intervention of an ophthalmologist. A rare complication of endoscopic dacryocystorhinostomy is the development of retrobulbar hemorrhage. This article presents a clinical case of the development of retrobulbar hemorrhage in endoscopic dacryocystorhinostomy. The patient with dacryocystitis underwent endoscopic dacryocystorhinostomy. Preoperative computed tomography revealed a lack of bone tissue in the lacrimal sac fossa. Severe bleeding was noted during the operation. Against the background of tamponade of the formed anastomosis, a growing exophthalmos, conjunctival chemosis, subconjunctival hemorrhage were noted. After removing the tampon, a positive trend was noted. Dexamethasone solution was intraoperatively intravenously administered, in the postoperative period - methylprednisolone solution. According to computed tomography data, exophthalmos persisted on the first day after the operation, hematoma was localized. Visual functions are unchanged. Six months after the operation, the patient had no complaints. According to the computed tomography data, a functioning dacryorhinostomy anastomosis was determined. Often, an interdisciplinary approach to such complications is required, since it can provide full orbital decompression, as well as adequate postoperative management of the patient, which contributes to the most complete ophthalmic rehabilitation. The interaction of otorhinolaryngologists and ophthalmologists in such cases is an indispensable condition for the safety of the operation.

Principles of Protection of the Eye and Vision in Orbital Surgery

Orbital surgery can result in damage to ocular and orbital structures, leading to a range of structural and visual sequelae, including corneal abrasions, globe malposition, diplopia, and blindness. Vision loss in particular is the most feared and devastating complication, occurs with an overall incidence of 0.84%, and can occur secondary to direct injury, optic nerve compression, or ischemic events. Different types of orbital surgery and surgical approaches carry their own hazards, and it is important to be mindful of these risks in addition to having a thorough understanding of individual risk factors and anatomical variations for each patient. Although universal guidelines for preserving vision in orbital surgery do not yet exist, there are concrete steps that every surgeon can take at the preoperative, intraoperative, and postoperative stages to minimize the risk of injury and maximize the likelihood of preserving the eye and visual function.

A Case of Transient Visual Disturbance and Ocular Paresis after Endoscopic Sinus Surgery

Endoscopic sinus surgery (ESS) is widely used as standard surgical treatment for chronic rhinosinusitis. Orbital complications of varying degrees occurred during ESS have been widely reported. If the orbital symptoms occurred immediately after surgery, ocular damage associated with surgery is suspected if the patient’s preoperative ocular function was patent. If immediate action is not taken, permanent visual loss might develop, so it is very important to diagnose orbital complications and take appropriate action. In our case, there was no definite intraorbital hemorrhage when sudden visual loss was noted. The symptoms were fully recovered without further treatment and it is clinically suspected to be caused by transient ocular muscle toxicity of local anesthetics.

A multi-centre, prospective epidemiological surveillance study considering ophthalmic complications of functional endoscopic sinus surgery

OBJECTIVES

This prospective, epidemiological British Ophthalmological Surveillance Unit study into ophthalmic complications of functional endoscopic sinus surgery aimed to determine the minimum incidence, presenting features and management throughout the UK.

METHODS

Cases of ophthalmic complications of functional endoscopic sinus surgery, between February 2016 and February 2018, were identified through the British Ophthalmological Surveillance Unit reporting card system. Reporting ophthalmic consultants were sent an initial questionnaire, followed by a second questionnaire at six months.

RESULTS

Twenty-six cases of ophthalmic complications of functional endoscopic sinus surgery were reported. The majority (16 cases (62 per cent)) had limitations of ocular motility at presentation. The most common final diagnosis was rectus muscle (33 per cent) and nasolacrimal duct trauma (27 per cent). Using national data, this study reports a minimum incidence of ophthalmic complications of functional endoscopic sinus surgery in the UK of 0.2 per cent over two years.

CONCLUSION

In terms of ophthalmic complications, functional endoscopic sinus surgery is shown to be safe. Ophthalmic complications are rare, but when they do occur, they commonly result in rectus muscle trauma, often requiring surgical intervention.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.

Anterior Ethmoidal Artery: A Computed Tomography Analysis and New Classifications

Objective  to determine the anterior ethmoidal artery (AEA) anatomy and variations by computed tomography (CT) in adult and their relations to and presents new AEA classifications. Methods  One hundred and fifty paranasal CT scans (300 sides) were included. Axial images were acquired with multiplanar reformates to obtain delicate details in coronal and sagittal planes. Results  One hundred and forty-four AEAs canal (48%), 293 AEAs foramen (97.7%), and 229 AEAs sulcus could be detected (76.3%). The mean AEA intranasal length was 6.7 ± 1.27 mm (range: 4.24-10.6 mm). The mean angle between AEA and lamina papyracea was 105.49 ± 9.28 degrees (range: 76.41-129.76 degrees). Of them, 95.8% AEAs had an angle with lamina >90 degrees, while 4.2% had angle <90 degrees. The mean angle between AEA and lateral lamella of cribriform plate was 103.95 ± 13.08 degrees (range: 65.57-141.36 degrees). Of them, 87.5% AEAs had an angle >90 degrees and 12.5% had an angle <90 degrees. The mean distance between AEA and skull base was 1.37 ± 1.98 mm (range: 0-8.35 mm). The AEA types in relation to skull base was type 1 (0-2 mm from skull base; 64.6%), type 2 (2-4 mm; 22.2%), type 3 (4-6 mm; 11.1%), and type 4 (>6 mm; 2.1%). The mean distance between the AEA and frontal sinus ostium was 9.17 ± 4.72 mm (range: 0-25.36 mm). AEA classification according to distance from AEA to frontal sinus ostium was 17.4% type 1 (<5 mm), 41.7% type 2 (5-10 mm), 31.9% type 3 (10-15 mm), and 9% type 4 (>15 mm). Conclusion  Provided AEA details improve surgeons' awareness of AEA variations in the endoscopic field and can help residents in training.

Medial Orbital Wall Reconstruction to Facilitate Endoscopic Sinus Surgery for Erosive Polypoidal Sinus Disease

The authors report the use of a 0.35-mm-thickness nylon implant for medial orbital wall reconstruction to facilitate functional endoscopic sinus surgery (FESS) for severe erosive polypoidal sinus disease while minimizing iatrogenic injuries to the orbital contents. A retrospective chart review identified 4 patients with extensive polypoidal sinus disease who underwent medial orbital wall reconstruction in the setting of FESS. All patients underwent successful reconstruction of bilateral eroded medial orbital walls using a 0.35-mm Supramid Foil Nylon Implant immediately followed by FESS. There were no permanent complications or iatrogenic injuries to the orbital contents due to FESS. All patients experienced improvement in sinus symptoms. Medial orbital wall reconstruction in the setting of erosive polypoidal sinus disease is a useful tool to help facilitate FESS. It allows the sinus surgeon to clear sinus disease aggressively with the orbits being protected from iatrogenic injury.

A rare complication of endoscopic sinus surgery: Retinal artery occlusion

A 60-year-old patient with a history of diabetes mellitus and coronary artery disease was admitted to the eye nose and throat clinic due to complaints of difficulty in breathing. The patient was decided for functional endoscopic sinus surgery with the diagnosis of right nasal polyposis and chronic sinusitis. The patient had right visual loss with the findings of retinal artery occlusion, which is a rare ocular complication seen after functional endoscopic sinus surgery. Although the patient had proper urgent surgical and medical treatment, we did not observe visual improvement. Since this is a very rare condition, we intended to report it in the literature.

Isolated Inferior Rectus Muscle Entrapment following Endoscopic Sinus Surgery

Orbital complications are known risks of endoscopic sinus surgery (ESS). The lamina papyracea and medial rectus muscle are the most commonly injured structures during ESS. Inferior rectus injury is more rare, with only one reported case of isolated inferior rectus injury in the literature. Guidelines for managing ESS-induced inferior rectus injury do not exist, and delayed intervention and management of adjacent sinuses may affect long-term outcomes such as persistent diplopia and disfigurement. In this report, we present a case of a 67-year-old man with diplopia due to isolated left inferior rectus muscle entrapment and injury from violation of the orbital floor during previous ESS. We postulate that an incomplete maxillary antrostomy contributed to scar band formation and entrapment of the inferior rectus muscle after the orbital floor was violated, and advocate early intervention with a wide, complete maxillary antrostomy if the orbital floor is injured during ESS.

Challenging Management of Double Vision After Functional Endoscopic Sinus Surgery-A Series of 6 Cases

PURPOSE

To present 6 cases of orbital trauma, diplopia and strabismus after functional endoscopic sinus surgery (FESS).

DESIGN

Retrospective observational case series.

METHODS

The medical charts of suitable patients were reviewed for information on medical examination, imaging studies, the type of corrective surgery, and surgical outcomes.

STUDY POPULATION

All patients with diplopia and strabismus after undergoing FESS who were treated or consulted at our institution between 2008 and 2017 were included.

MAIN OUTCOME MEASURES

The presence and extent of strabismus and double vision at the end of follow-up.

RESULTS

Six patients complained of diplopia after FESS; all of them had proven orbital trauma. In Cases 1-5, patients suffered medial rectus (MR) muscle transection and subsequent exotropia. Their prognosis was guarded despite prompt surgical intervention, and ranged from large exotropia when direct recovery of the MR was attempted, to primary gaze orthotropia but with minimal adduction capacity, during which vertical recti transposition was attempted. Patient 6 sustained transient diplopia, although all of his extraocular muscles appeared intact on imaging. His eye position and movement were completely resolved with conservative measures only.

CONCLUSIONS

Our experience was that immediate recovery procedures to reattach the muscle in cases with proven transection of the MR muscle are futile, and that definitive corrective strabismus surgery (ie, vertical muscle transposition) has a better chance to achieve favorable results.

Lamina papyracea position in patients with nasal polypi: A computed tomography analysis

OBJECTIVE

This study aimed to describe the positions of the lamina papyracea (LP) in patients who had nasal polypi, by computed tomography (CT) analysis.

METHODS

Paranasal CT scans of patients diagnosed to have nasal polypi were included in the study. CT images were acquired with multiplanar reformates to obtain delicate details in coronal planes for all subjects. Positions of the LP were registered then analyzed in relation to nasal polypi grading.

RESULTS

Forty seven subjects (94 nasal sides) were included in the current study. Grade I lamina detected in 50% or more of all cases. Patients who had larger polypi (polyp grade 3, 4) were associated with significantly more medial LP (grade II) than smaller polypi (polyp grade 0, 1, 2) (P=0.00386).

CONCLUSION

The current study improves surgeons' awareness of LP position in different grades of nasal polypi and highlights that larger polypi are significantly associated with more medial LP than smaller polypi. This may be one of the causes of the higher incidence of complication in larger polypi and can help for safer surgery.

Ophthalmic comlications of functional endoscopic sinus surgery

Functional endoscopic sinus surgery (FESS) is an effective and safe surgical technique, which revolutionized the surgical management of nasal cavity and paranasal sinus diseases. The intimate connection between paranasal sinuses and the orbit places the orbital content at a risk of injury during sinus surgery, especially that of ethmoid sinuses. The orbit, the optic nerve, extraocular muscles and the lacrimal drainage system could be damaged during FESS. The risk of injury correlates to anatomical variations, degree and severity of disease, previous procedure results, and surgical experience. Ophthalmic complications can vary in severity from minor ones, such as localized hematomas, to extremely dangerous, such as optic nerve injury, that could lead to complete blindness. In order to minimize the risk of such complications, it is necessary to consider probable anatomic variations of paranasal sinuses and orbit, which are to be detected by CT scan before surgery.

Long-term therapeutic outcome of ophthalmic complications following endoscopic sinus surgery

Ophthalmic complications associated with endoscopic sinus surgery (ESS) are quite rare. There is a paucity of reliable data and limited experience on the clinical findings and treatments of these injuries. Our study here is to characterize the types of orbital injury following ESS, in particular extraocular muscle injury, and to evaluate the long-term therapeutic outcomes as compiled from a relatively large sample of Chinese patients.A series of 27 patients (21 males and 6 females; mean age = 42.6 years, ranges: 10-60 years) were retrospectively reviewed. The mean duration of orbital complication was 6.6 months (ranges: 1 day to 24 months). The right eye was affected in 19 patients and the left in 8 patients. All patients had various extraocular muscle dysfunction, including contusion, oculomotor nerve damage, muscle entrapment, muscle transection, and muscle destruction. All patients subjected to strabismus surgery showed an obvious reduction in deviation. Three patients achieved orthophoria without any surgery during the period of observation. All patients displayed mild to complicated orbital hemorrhage that often disappeared within 2 weeks. Optic nerve injury occurred in 29.6% of patients and vision damage in these patients was often irreversible.All patients with ophthalmic complications after ESS had strabismus and extraocular muscle dysfunction. Timing and type of strabismus surgery performed depended on the severity and number of muscles involved as well as the type of injury. This surgery is less effective in cases of restriction factor adhesion and/or entrapment as compared to that of patients with other types of strabismus. Orbital hemorrhages were usually resolved spontaneously, but optic nerve injury was mostly irreversible.

Preventing and Managing Complications in Frontal Sinus Surgery

This review covers potential complications of frontal sinus surgical management and strategies for prevention of these complications. Accordingly, recent advances in frontal sinus surgical techniques are described, and the management of complications stemming both from these and traditional techniques are detailed.

Ophthalmic complications of endoscopic sinus surgery

Introduction

The proximity of the paranasal sinuses to the orbit and its contents allows the occurence of injuries in both primary or revision surgery. The majority of orbital complications are minor. The major complications are seen in 0.01–2.25% and some of them can be serious, leading to permanent dysfunction.

Objective

The aim of this study was to determine the risk and type of ophthalmic complications among patients operated due to a chronic rhinosinusitis.

Methods

This is a retrospective study of 1658 patients who underwent endoscopic sinus surgery for chronic rhinosinusitis with or without polyps or mucocele. Surgeries were performed under general anesthesia in all cases and consisted of polyps’ removal, followed by middle metal antrostomy, partial or complete ethmoidectomy, frontal recess surgery and sphenoid surgery if necessary. The ophthalmic complications were classified according to type, frequency and clinical findings.

Results

In our material 32.68% of the patients required revision surgery and only 10.1% had been previously operated in our Department. Overall complications occurred in 11 patients (0.66%). Minor complications were observed in 5 patients (0.3%) with the most frequent being periorbital ecchymosis with or without emphysema. Major complications were observed in one patient (0.06%) and were related to a lacrimal duct injury. Severe complications occurred in 5 cases (0.3%), with 2 cases and referred to a retroorbital hematoma, optic nerve injury (2 cases) and one case of extraocular muscle injury.

Conclusions

Orbital complications of endoscopic nasal surgery are rare. The incidence of serious complications, causing permanent disabilities is less than 0.3%. The most important parameters responsible for complications are extension of the disease, previous endoscopic surgery and coexisting anticoagulant treatment.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

An Approach to Some Aspects of Strabismus from Ocular and Orbital Trauma

Strabismus caused by ocular or orbital trauma can be the result of localized acute soft tissue swelling or may follow orbital fractures, partial or complete loss of extraocular muscle (EOM) and/or cranial nerve function, or damage to surrounding tissues causing mechanical restriction. The strabismus is frequently incomitant and can be difficult, if not impossible to completely correct. The resulting diplopia can affect the individual's ability to function at work, in sports and in common tasks of daily living like driving. The preoperative evaluation should include an assessment of the degree of limitation, muscle function and the condition of the surrounding tissue. In most cases, high resolution computed tomography and/or surface coil dynamic magnetic resonance imaging are required to determine the extent and nature of suspected bony or EOM injury, as well as muscle contractility. If the scan reveals an intact but paretic muscle or only minor muscle injury, surgical intervention is based on the degree of muscle recovery 6 months after the initial insult. If a rectus muscle has been lacerated, and the proximal stump is functional, retrieval should be attempted, either by a direct conjunctival approach if located anteriorly, or by an anterior medial orbitotomy if located deep in the orbit. If a damaged muscle cannot be found, recovered or repaired at any time, then muscle transposition should be considered. If multiple muscles are damaged or scar tissue is excessive, a tether procedure may be indicated. This paper will present an approach to some aspects of strabismus in this setting.

Iatrogenic Injury to Medial Rectus After Endoscopic Sinus Surgery

Endoscopic sinus surgery (ESS) is the mainstay of the treatment in sinus disorders, to re-establish the drainage of the affected sinus. The close proximity of the orbital structures to paranasal sinuses makes them vulnerable to inadvertent injury during the sinus surgery. Medial rectus (MR) muscle is the most commonly injured extraocular muscle during ESS due to its anatomic proximity to the thin medial wall of the orbit. This is a non-comparative, retrospective, interventional case series of six patients presenting with MR injury after ESS. We discuss the management, outcome and review the published literature. A total of six patients met the inclusion criteria. The presenting complaints were diplopia, squinting and limitation of ocular movements. Two patients underwent surgical exploration of the MR muscle and reattachment of the muscle along with injection botulinum to the antagonist lateral rectus muscle. Two patients who had small angle strabismus and who were able to fuse were advised orthoptic exercises and prisms as management. Remaining two patients were advised surgical intervention to correct strabismus but they declined further surgical intervention. Management of MR injury following ESS is complex, often resulting in suboptimal outcomes. Since early intervention is associated with better outcomes, early referral by otolaryngologists to ophthalmologists would result in better outcome.

Medial Rectus Muscle Injuries after Functional Endoscopic Sinus Surgery

In recent years, functional endoscopic sinus surgery (FESS) has improved the treatment of sinus disorders. However, various orbital complications have been reported, including optic nerve damage, orbital hemorrhage, infection, lacrimal drainage system injury, and strabismus. Complications are rare but may cause severe morbidity. We describe two patients who underwent endoscopic sinus surgery procedures that resulted in trauma to the medial rectus muscle. The first patient had medial rectus paresia due to contusional trauma and showed spontaneous resolution in a month. The other patient had an orbital medial wall defect with medial rectus injury and he underwent orbitotomy. Medial rectus innervation returned at postoperative 8 months. Several extraocular muscles may be traumatized during FESS. Timing and method of treatment are based on the severity and type of injury and the number of muscles involved. Treatment strategies are dependent on accurate interpretation of magnetic resonance imaging scans.

Orbital Complications Associated with the Treatment of Chronic Rhinosinusitis

Orbital injuries from endoscopic sinus surgery are rare but potentially catastrophic. The most feared complications from sinus surgery include blindness and diplopia. Recent publications note that the rate of orbital complications has decreased when compared with the past, reflecting the use of endoscopes, better technology, and improved training. The sinus surgeon must have mastery over the procedure she or he plans to undertake and be aware of the specific potential for orbital injury given the patient's anatomy and disease. The sinus surgeon must also have expert knowledge of the appropriate and immediate medical and surgical management of orbital complications.

Rare and Other Notable Complications in Endoscopic Sinus Surgery

This article focuses on the rare and obscure complications of endoscopic sinus surgery. The majority of surgeons will not encounter these complications in their practice, but should be aware of their possibility. With knowledge of these rare complications, the surgeon can understand the possible avoidance as well as urgent management of these problems.

Pitfalls in Sinus Surgery: An Overview of Complications

There is a potential for significant complications from the medical and surgical treatment of rhinosinusitis because of the intimate relationship between the paranasal sinuses and surrounding vital structures. Familiarity with the complex anatomic relationships between the skull base and other critical structures and knowledge of pharmacologic properties of commonly used medical therapies are essential for preventing serious and harmful seqsuelae. The authors hope that this review represents a valuable addition to the otolaryngologist-in-training's therapeutic armamentarium, and also serves as a reminder of the potential pitfalls for the experienced sinus surgeon.

Avoiding Complications in Endoscopic Sinus Surgery

Complications of endoscopic sinus surgery (ESS) can range from the mundane to the catastrophic, with nasal hemorrhage being the most common. Intraorbital and intracranial complications are much less common. Despite the rarity of complications, they are often avoidable. Certain identifiable risk factors can be appreciated during the preoperative, intraoperative, and postoperative evaluations of the sinus patient. With awareness of these risk factors the rhinologist can develop a strategic plan of risk factor mitigation. This article identifies areas of increased risk that are amenable to preventive strategies before complications become realized.

Variations of lamina papyracea position from the endoscopic view: a retrospective computed tomography analysis

BACKGROUND

Accidental injury of lamina papyracea (LP) remains one of the most common complications reported in endoscopic sinus surgery (ESS) even in most recent studies. The purpose of this study was to categorize the LP position radiologically and from an endoscopic perspective.

METHODS

A total of 207 computed tomography (CT) scans (414 sides) including both diseased and control groups were retrospectively reviewed by 2 examiners. Inferior turbinate attachment to the lateral nasal wall and the inferior margin of the planned middle meatal antrostomy (MMA) were identified anteriorly. Position of LP in relation to the vertical line passing through MMA inferior margin was reported. LP was categorized to lie either within 2 mm on either side of the MMA inferior margin (type I), more than 2 mm medial to the MMA line (type IIa: 2 to 4 mm; type IIb: >4 mm), or more than 2 mm lateral to the MMA line (type IIIa: 2 to 4 mm; type IIIb: >4 mm).

RESULTS

Of the 221 sides in the control group, 69.7% were classified as type I, 24.9% as type II, and 5.5% as type III. Among the 193 diseased operated sides examined, 60.1% were classified as type I, 20.2% as type II, and 13.5% as type III. Weighted kappa coefficient showed good interexaminer reliability. Five sides (2.6%) in the case group had accidental LP penetration intraoperatively, 4 of them were type II and type III LP.

CONCLUSION

This study improves surgeons' awareness of LP variations in the endoscopic field and can be of help for residents in training.

Risks and medico-legal aspects of endoscopic sinus surgery: a review

The aim of this study was to perform a systematic literature review of risks and medico-legal aspects of endoscopic sinus surgery. The development of sophisticated technologies and instruments for endoscopic sinus surgery (ESS) has caused a dramatic increase in the number of otolaryngologists performing sinus surgery and the number of cases performed. This expansion was accompanied by an increase in malpractice lawsuits. Over the past 20 years, rhinology claims represented 70 % of the total indemnity compensation for otolaryngology claims and ESS was the surgical procedure most often involved. Only then will a careful analysis and assessment of the possible and potential risk factors of ESS, which may mislead the surgeon, allow a correct clinical risk management, with activities and procedures aimed at reducing the possibility of complications that may expose the physician to a malpractice suit.

Application of endoscopic techniques in orbital blowout fractures

Minimally invasive surgical techniques, particularly endoscopic techniques, have revolutionized otolaryngeal surgery. Endoscopic techniques have been gradually applied in orbital surgery through the sinus inferomedial to the orbit and the orbital subperiosteal space. Endoscopic techniques help surgeons observe fractures and soft tissue of the posterior orbit to precisely place implants and protect vital structures through accurate, safe, and minimally invasive approaches. We reviewed the development of endoscopic techniques, the composition of endoscopic systems for orbital surgery, and the problems and developmental prospects of endoscopic techniques for simple orbital wall fracture repair.

Complications of vision loss and ophthalmoplegia during endoscopic sinus surgery

OBJECTIVE

To describe two rare cases of concurrent vision loss and external ophthalmoplegia following powered endoscopic sinus surgery (ESS).

DESIGN

Observational case report.

RESULTS

The records of two patients who underwent powered ESS and developed multiple concurrent ophthalmic complications were retrospectively reviewed for clinical history, neuro-ophthalmologic examination, and imaging findings. Patient 1 developed a retinal vascular occlusion and complete loss of adduction. Patient 2 developed an orbital hemorrhage, optic neuropathy, and a restrictive global ophthalmoplegia. Similar published case reports were also reviewed.

CONCLUSION

Despite advances in powered ESS technique and instrumentation, serious ophthalmic complications can still occur. Inadvertent entry into the medial orbital wall can result in a combination of blindness and ocular motility dysfunction. The variety of mechanisms responsible for these complications underscores the importance of thorough pre- and postoperative clinical examination and review of imaging studies.

A case report of orbital haemorrhage associated with endoscopic sinus surgery and reversible sight loss: a multidisciplinary approach to management

We report a case of intraoperative orbital haemorrhage as a complication of endoscopic sinus surgery performed under general anaesthesia. Initial unilateral complete visual loss occurred, but recovered due to accurate and early diagnosis combined with urgent surgical intervention. This patient's case is reported to illustrate the importance of early recognition of clinical signs and how a stepwise approach to management can result in a favourable visual outcome. Moreover, the mechanisms and pathophysiology of visual loss due to orbital haemorrhage following endoscopic sinus surgery are discussed.

[Management of motility disorders secondary to iatrogenic orbital fracture during endoscopic sinus surgery]

PURPOSE

Orbital wall fracture may occur during endoscopic sinus surgery, resulting in oculomotor disorders. We report the management of four cases presenting with this surgical complication.

METHODS

A non-comparative observational retrospective study was carried out on four patients presenting with diplopia after endoscopic ethmoidal sinus surgery. All patients underwent full ophthalmologic and orthoptic examination as well as orbital imaging.

RESULTS

All four patients presented with diplopia secondary to a medial rectus lesion confirmed by orbital imaging. A large horizontal deviation as well as limitation of adduction was present in all cases. Surgical management consisted of conventional recession-resection procedures in three cases and muscle transposition in one patient. A useful field of binocular single vision was restored in two of the four patients.

CONCLUSION

Orbital injury may occur during endoscopic sinus surgery and cause diplopia, usually secondary to medial rectus involvement due to the proximity of this muscle to the lamina papyracea of the ethmoid bone. Surgical management is based on orbital imaging, duration of the lesion, evaluation of anterior segment vasculature, results of forced duction testing and intraoperative findings. In most cases, treatment is aimed at the symptoms rather than the cause, and the functional prognosis remains guarded.

CT and MR imaging findings of periorbital lipogranuloma developing after endoscopic sinus surgery

SUMMARY

Periorbital lipogranuloma is a rare complication after ESS and presently lacks specific imaging reports. The purpose of this study was to describe the CT and MR imaging features of periorbital lipogranuloma. We retrospectively reviewed 9 patients with histology-confirmed periorbital lipogranuloma. All 9 patients underwent CT and MR imaging. Five lipogranulomas were located in the right eyelid and 4 in the left eyelid, which extended into the extraconal space to some degree. The lesions displayed an irregular shape and had an ill-defined margin. Multiple, specked, or nodular foci containing fat were scattered within these lesions. The lesions demonstrated moderate heterogeneous contrast enhancement on contrast-enhanced MR imaging. The TICs showed a persistent pattern (type I) in 6 patients undergoing DCE MR imaging. Thus, an ill-defined, irregular-shaped periorbital mass with multiple foci containing fat, combined with an ESS history, can help to accurately diagnose this entity.

Orbital compartment syndrome following aneurysm surgery

Orbital compartment syndrome (OCS) is a rare cause of blindness following intracranial surgery. We report a patient with OCS following intracranial cerebrovascular surgery precipitated by severe straining. OCS occurred due to a rapid increase in intraorbital pressure within the rigid confines of the orbit causing hypoperfusion of critical neural structures, which resulted in visual loss and a complete external ophthalmoplegia. Treatment involved urgent surgical soft tissue decompression of the orbit, corticosteroids and osmotic agents. It is important to consider OCS as a cause of blindness in the neurosurgical postoperative setting as without rapid treatment this condition has a very poor prognosis.

[Complications from sinonasal surgery]

Endoscopic sinonasal surgery is the main procedure in sinonasal pathology. Complications are rare but potentially severe given the close relationship between the nasal cavities and sinuses and the orbit, skull base and carotid arteries. The different types of surgeries along with the mechanisms of injury, presenting signs and symptoms, and imaging features of the different surgical complications will be reviewed. We will also review the anatomical variants increasing the surgical risk that radiologists should describe on preoperative imaging studies.