Carotid artery injury after endonasal surgery

The Learning Curve for Endoscopic Endonasal Transsphenoidal Pituitary Surgery: Evaluating Endocrine Outcomes

OBJECTIVE

In South Australia endoscopic endonasal approach (EEA) pituitary surgery has been practiced since 2006, largely by two neurosurgeons with a small fellowship-trained otolaryngology team. The aim of this cohort study was to determine if a "learning curve" can be established over this time period, as represented by structural and endocrine patient outcomes.

METHOD

Retrospective cohort study of patients undergoing EEA surgery between 2006 and 2021 in Adelaide, South Australia at three tertiary teaching hospitals.. Cases were divided by each surgeon and split into groups of sequential 40 cases. Endocrine assessment pre- and post-operatively involved static pituitary and end-organ hormones, with dynamic tests as required, assessed by an pituitary endocrinologist. Each hormonal axis (gonadal, cortisol, thyroid, prolactin and growth hormone) was documented preoperatively and at an early and long term follow up at 1-2 and 12 months, respectively.

RESULTS

The study included a cohort of 443 pituitary adenomas managed with endoscopic endonasal transsphenoidal surgery in a consecutive fashion between two neurosurgeons over 16-years. Gross tumour resection but not visual visual outcomes improved with surgical experience but this outcome may be neurosurgeon dependent. Endocrine outcomes were not consistently improved with experience, but lower rates of hypopituitarism were seen with experience with one neurosurgeon. Average follow up was approximately 5 years, and a minimum follow up of 12 months for all patients.

CONCLUSIONS

We present long term endocrine follow up for patients with functional and non-functional adenomas. Improved rates of gross tumour resection were evident with with surgical experience. However, there was no apparent change in post-operative endocrine outcomes.

Internal carotid artery injury during endoscopic transsphenoidal pituitary surgery: risk factors, management

BACKGROUND

Transsphenoidal surgeons should try to avoid internal carotid artery (ICA) injury but also be prepared to manage it. We analyzed our experience with ICA injury during endoscopic transsphenoidal pituitary surgery and present associated risk factors and a management protocol.

METHODS

We retrospectively reviewed and analyzed the medical records of 1596 patients who underwent endoscopic transsphenoidal surgery for pituitary tumor resection in our institution from January 2009 to October 2022.

RESULTS

Six patients experienced an ICA injury. All received timely and effective hemostasis with immediate direct tamponade followed by endovascular treatment. No serious postoperative complications occurred.

CONCLUSIONS

We proposed a treatment plan for ICA injuries encountered during endoscopic transsphenoidal surgery and described our hemostasis process, methods of endovascular treatment, and means of postoperative follow-up in detail.

The learning curve for endoscopic endonasal pituitary surgery: a systematic review

Recent literature demonstrates that a learning curve exists for endoscopic pituitary surgery. However, there is significant variability in the way these studies report their outcomes. This study aims to systematically review the literature regarding outcomes for endoscopic pituitary surgery and how this may be related to a surgical learning curve. An electronic search of the databases Medline, Scopus, Embase, Web of Science and Cochrane Library databases was performed and data extracted according 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Ten articles were included in the review as they examined the following: rates of gross total resection, average operative time, CSF leak rate, visual outcomes, endocrine outcomes and how these results were influenced by surgical experience. We have demonstrated that a learning curve exists for some outcome variables for endoscopic pituitary surgery. However, there is significant heterogeneity in the current body of literature which makes clear comparisons difficult.

Internal carotid artery injury during endoscopic endonasal surgery for skull base pathologies: an institutional incidence, management, and outcome

BACKGROUND

Endoscopic endonasal surgery (EES) has become a popular approach to deal with skull base pathologies. The most catastrophic intra-operative complication of EES is internal carotid artery (ICA) injury. We aim to discuss and introduce our institutional experience with ICA injury during EES.

METHODS

A retrospective review of patients who underwent EES from 2013 to 2022 was performed to determine the incidence and outcomes of intraoperative ICA injuries.

RESULTS

There were six patients (0.56%) with intraoperative ICA injury in our institution during the last 10 years. Fortunately, there was no morbidity or mortality in our patients with intraoperative ICA injuries. The sites of injury were equally in paraclival, cavernous sinus, and preclinoidal segments of ICA.

CONCLUSION

Primary prevention is the best solution for this condition. Regarding our institutional experience, the best option for primary management just after an injury is packing the surgical site. In cases where packing is not enough for temporary control of bleeding, common carotid artery occlusion should be considered. We have presented our experience and reviewed previous studies regarding different treatments and suggested our intra and post-operative management algorithm.

Internal Carotid Artery Pseudoaneurysm After Transsphenoidal Pituitary Tumor Resection: A Case Report

Here, we present a case report on internal carotid artery pseudoaneurysm (ICAP) which highlights a rare but potentially life-threatening complication of transsphenoidal pituitary surgery. A 32-year-old male underwent resection of a pituitary tumor and developed a large cerebrospinal fluid (CSF) leak during surgery, which was reconstructed with a fat graft and nasoseptal flap. Postoperatively, he was recovering well and discharged without complications; however, eight days after surgery he returned with massive epistaxis and hematemesis. This was initially managed with endoscopic exploration, nasal packing, and transfusion of blood products. Imaging revealed a pseudoaneurysm on the right internal carotid artery. The patient was started on aspirin and clopidogrel, and a flow diverter stent was placed without complications. Our case emphasizes the importance of prompt recognition and management of vascular injuries such as an internal carotid pseudoaneurysm after transsphenoidal pituitary surgery to prevent catastrophic outcomes.

Emergency treatment and anesthesia management of internal carotid artery injury during neurosurgery: Four case reports

BACKGROUND

During skull base surgery, intraoperative internal carotid artery (ICA) injury is a catastrophic complication that can lead to fatal blood loss or secondary cerebral ischemia. Appropriate management of ICA injury plays a crucial role in the prognosis of patients. Neurosurgeons have reported multiple techniques and management strategies; however, the literature on managing this complication from the anesthesiologist’s perspective is limited, especially in the aspect of circulation management and airway management when patients need transit for further endovascular treatment.

CASE SUMMARY

We describe 4 cases of ICA injury during neurosurgery; there were 3 cases of pathologically proven pituitary adenoma and 1 case of cavernous sinus endothelial meningioma. After the onset of ICA injury, all four patients were immediately transferred for endovascular therapy under general anesthesia with vital signs monitored and mechanical ventilation. Three patients were transferred to the hybrid operating room, and one patient was transferred to the catheter operating room. Three patients underwent covered stent implantation, and one patient underwent embolization. All four patients experienced hypovolemic shock and received blood products infusion and vasoactive drugs to maintain stable circulation. After the neurosurgery, one patient was extubated and returned to the ward, and the other three were delayed tracheal extubation and returned to the intensive care unit. One patient died from serious neurological complications after 62 d in the hospital, but the other three showed good clinical outcomes.

CONCLUSION

ICA injury imposes a high risk of massive hemorrhage and subsequent infarction. Immediate treatment is critical and requires interdisciplinary collaboration among neurosurgeons, anesthesiologists, and interventional neuroradiologists. Effective hemostatic methods, stable hemodynamics sufficient to ensure perfusion of vital organs, airway safety during transit, rapid localization and implementation of appropriate measures to occlude the damaged vessel are strong guarantees of patient safety.

Risky anatomical variations of sphenoid sinus and surrounding structures in endoscopic sinus surgery

Purpose

This study aimed to examine the relationship between the sphenoid sinus (SS) and surrounding vital structures such as the internal carotid artery (ICA) and optic nerve canal (ONC) as well as the types of attachment of the sphenoidal septa onto these structures.

Methods

In total, 230 computed tomography (CT) scans were reviewed to study the type of sphenoid sinus pneumatization (SSP), the protrusion and dehiscence of the ICA and ONC, the relationship between the sphenoidal septa and surrounding vital structures as well as pterygoid recess pneumatization (PRP).

Results

The most common SSP was sellar type (58.7%). The rates of protrusion and dehiscence of the ICA were 26.3 and 0.4%, and for the ONC, they were 13 and 1.5%, respectively. The ICA and ONC were most protruded and dehiscent in more extensive SSP. In 21.6% of patients, the intersphenoidal septa (IS) were attached to the wall of the ICA and in 8.6% they were attached to the wall of the ONC. The attachment of IS to the ICA correlated statistically significantly (p < 0.0001) with protrusion of the ICA. Accessory septa were detected in 30.4% of cases with various sites of attachment.

Conclusion

To reduce the risk of injury and complications during endoscopic sinus surgery (ESS), surgeons should consider using CT to identify possible bulging and dehiscence of the ICA/ONC and their relationship to the extent of SSP and also to establish the presence of deviation of the sphenoid septum, and the presence of accessory septa.

Development of a management protocol for internal carotid artery injury during endoscopic surgery: a modified Delphi method and single-center multidisciplinary working group

BACKGROUND

Intra-operative internal carotid artery (ICA) injury during transnasal endoscopic surgery is a potentially catastrophic event. Such an injury is life-threatening in the immediate setting, with a reported peri-operative mortality rate of 10%. Nasal packing, muscle patches, direct vessel closure, and endovascular techniques have been described as useful strategies for managing ICA bleeds. The objective of this study was to develop a formalized management protocol for intra-operative ICA injury through engagement with a multi-disciplinary panel.

METHODS

A modified Delphi method including literature review, iterative rounds of stakeholder feedback, and expert panel discussions was used to develop a management protocol for ICA injury during transnasal endoscopic surgery. The 10-person multi-disciplinary panel included otolaryngologists, neurosurgeons, interventional neuroradiologists, anesthesiologists, and operating room nursing staff.

RESULTS

After three rounds of stakeholder engagement with the expert panel, consensus was reached on important elements to include within the protocol. The protocol was divided in three categories: Alert, Control, and Transfer. 'Alert' focusses on early communication with anesthesia and nursing staff. 'Control' focusses on techniques to expose the injury and obtain hemostasis or adequate tamponade. Lastly, 'Transfer' describes the process of contacting neuro-interventional radiology and safely transferring the patient. A one-page handout of the protocol was developed for placement in operating theatres.

CONCLUSION

Due to the life-threatening nature of ICA injury, it is imperative that endoscopic sinus and skull base surgeons are prepared to manage this complication. Using a modified Delphi method with a multidisciplinary expert panel, a protocol for management of intra-operative ICA injury was developed.

Embolization after internal carotid artery injury secondary to transsphenoidal pituitary surgery and delayed intranasal coil protrusion: illustrative case

BACKGROUND

The authors presented a case of spontaneous nasopharyngeal coil migration that occurred 3 years after a patient had undergone transsphenoidal resection due to pituitary macroadenoma and was treated with coil application because of internal carotid artery injury secondary to transsphenoidal resection of the pituitary macroadenoma.

OBSERVATIONS

In the literature, eight cases of coil migration that occurred between 2 and 120 months after coil application have been reported, most of which were treated with surgical removal of the coil in a same-day surgery setting.

LESSONS

The case presented emphasized that coil protrusion and migration may lead to destruction in the skull base, thereby leading to serious consequences if left untreated, even in the absence of history of trauma. To the authors’ knowledge, this is the first case in the literature that required additional invasive procedures due to recurrent bleeding that occurred several months after surgical removal of coils. Also, this report underlined the need for careful and long-term follow-up of coil materials used for the treatment of pseudoaneurysms caused by vascular injuries secondary to skull base injury during surgery.

Complications of Endoscopic Skull Base Surgery for Sellar and Parasellar Tumors in Pediatric Population; Neurosurgical Perspectives

Background

Advances in surgical techniques based on in-depth anatomical knowledge of the skull base have broadened the indications for endoscopic skull base surgery (ESS) with the advantage of wide and direct surgical exposure while minimizing invasiveness. However, the low incidence of the indicated diseases and narrow surgical corridors in children have limited the popularization of ESS. In addition, surgical complications and preventive interventions are not yet well known. Therefore, we retrospectively investigated the complications and prevention methods of ESS in children with a comprehensive review.

Methods

We retrospectively analyzed the medical records of pediatric patients who underwent ESS for sellar and parasellar tumors at Seoul National University Children's Hospital from July 2010 to December 2020. Visual and endocrine status, extent of resection, complications, and recurrences were investigated depending on the pathology of the tumor. In addition, a comprehensive literature review regarding the complications of pediatric ESS was performed.

Results

A total of 98 patients were enrolled. The median age of the patients was 12 years, and 52 patients were male. Preoperative visual disturbance was found in 53 patients, anterior pituitary function deficit in 69, and diabetes insipidus in 32. Gross total resection was attempted in 67 patients and achieved in 62 (93%). Biopsy and cyst fenestration were the goals of surgery in 26 patients, and all were achieved as planned. Regarding outcomes, visual disturbance worsened in two patients (2%), endocrine status was aggravated in 34 (35%) patients, and new-onset diabetes insipidus occurred in 27 (41%) patients. The overall surgical complication rate (other than aggravation of visual or endocrine status) was 17%. Postoperative meningitis (12%) was the most common complication, followed by cerebrospinal fluid leakage (2%), vasospasm, hemorrhage and infarction. By pathological diagnosis, craniopharyngioma had the highest complication rate of 29%. All but one patient with postoperative hemorrhage showed no permanent deficits.

Conclusion

ESS in children is feasible and relatively safe. More attention and different postoperative management protocols are required in children to avoid complications, especially in craniopharyngiomas. However, the complications can be mostly managed conservatively without permanent neurologic deficits.

Carotid artery injury in endoscopic endonasal surgery: Risk factors, prevention, and management

Objective

Endoscopic approaches for sinus and skull base surgery are increasing in popularity. The objective of this narrative review is to characterize risk factors for internal carotid artery injury in endoscopic endonasal surgery (EES), highlight preventative measures, and illustrate key management principles.

Data Sources

Comprehensive literature review.

Methods

Relevant literature was reviewed using PubMed/MEDLINE.

Results

Carotid artery injury in EES is rare, with most studies reporting an incidence below 0.1%. Anatomic aberrancies, wide dissection margins, as well as specific provider and hospital factors, may increase the risk of injury. Multidisciplinary teams, comprehensive preoperative imaging, patient risk assessment, and formal training in vascular emergencies may reduce the risk. Management protocols should emphasize proper visualization of the injury site, fluid replacement, rapid packing, angiography, and endovascular techniques to achieve hemostasis.

Conclusions

While EES is a relatively safe procedure, carotid artery injury is a devastating complication that warrants full consideration in surgical planning. Important preventative measures include identifying patients with notable risk factors and obtaining preoperative imaging. Multidisciplinary teams and management protocols are ultimately necessary to reduce morbidity and mortality.

Carotid Artery-Cavernous Segment Injury during an Endoscopic Endonasal Surgery: A Case Report and Literature Review of the Overlooked Option for Surgical Trapping in the Hyperacute Phase

Internal carotid artery (ICA) injury is a catastrophic complication of endoscopic endonasal surgery (EES). However, its standard management, emergent endovascular treatment, may not always be available, and the transnasal approach may be insufficient to achieve hemostasis. A 44-year-old woman with pituitary adenoma underwent EES complicated with the ICA cavernous segment injury (CSI). In urgent intraoperative angiogram, a good collateral flow from the contralateral carotid circulation was observed. Due to the unavailability of intraoperative embolization, emergent surgical trapping was performed by combined transcranial and cervical approach. The patient recovered but later developed a giant cavernous pseudoaneurysm. During the pseudoaneurysm embolization, ICA was directly accessed via a 1.7-F puncture hole using a bare microcatheter technique. Then, both the aneurysm and parent artery were obliterated with coils. At the 4-year follow-up, the patient was asymptomatic without a residual tumor. To our knowledge, this is the first case of ICA-CSI during EES successfully treated with ICA trapping as a lifesaving urgent surgery that achieved a complete recovery after a pseudoaneurysm embolization. Although several studies reported that EES-related ICA-CSIs with percutaneous carotid artery access, neither our surgical salvage technique nor our carotid access and tract embolization techniques were previously described.

The potential of chitosan-based haemostats for use in neurosurgical setting - Literature review

Haemorrhage is a major nuance in neurosurgery since blood can distort the surgeon's field of view and increase the risk of post-operative complications. Currently a variety of commercially available haemostats have been approved for use in neurosurgery, but they have caveats to their use in the brain, including, localised tissue compression, neural toxicity, induce immune reaction or form thrombus within the vessel. Thus, there is a need for haemostats that are efficacious and safe for application on brain and spinal tissue. Chitosan is a naturally occurring bio-polymer that is found on the exoskeleton of arthropods and the cell wall of fungi. Chitosan has been shown to accelerate haemostasis through a myriad of physiological pathways. These findings have led to the development of multiple chitosan-based haemostats, for use in peripheral human tissue. Although, clinical data regarding the use of chitosan-based haemostats in the brain is lacking, a range on in vivo studies have proven chitosan to be efficacious and safe in managing neurosurgical bleeds. Similarly, literature comparing chitosan-based haemostats with commercial haemostats used commonly in neurosurgery, have all demonstrated chitosan to be the superior agent. Additionally, clinical trials of chitosan-based haemostat used in peripheral tissue have all demonstrated chitosan to be safe for human use. The marriage of these findings indicates that the safety and superior efficacy of chitosan-based haemostat, makes it a potentially suitable haemostat for use in neurosurgical setting. However, further research pertaining to the clinical use of chitosan-based haemostat within the central nervous system needs to be conducted.

The surgical management of intraoperative intracranial internal carotid artery injury in open skull base surgery-a systematic review

Intraoperative internal carotid artery (ICA) injury during open skull base surgery is a catastrophic complication. Multiple techniques and management strategies have been reported for endoscopic skull base surgery; however, the literature on managing this complication in open skull base surgery is limited. To perform a systematic review and give an overview of the different techniques described to manage this complication intraoperatively, a systematic review was conducted in PubMed, Ovid Medline, Ovid Embase and Scopus for literature published until July 2021. Titles and abstracts were screened. Studies meeting prespecified inclusion criteria were reviewed in full. PRISMA guidelines were strictly adhered to. Out of 4492 articles, only 12 articles could be included, reflecting an underreporting of open skull base ICA injuries. Multiple techniques can be used depending on the location and size of the injury as well as the surgeon's experience. Described techniques include the following: a primary repair via a micro-suture or nonpenetrating clips; wrapping or plugging; coating; occlusion of the parent artery with or without a bypass; packing with further endovascular management. A treatment algorithm is proposed.

Magnetic resonance angiographic study of variations in course of paraclival and parasellar internal carotid artery in relation to expanded endonasal endoscopic approaches

AIMS

To study the variations in the course of the paraclival and parasellar carotid arteries in normal subjects using magnetic resonance angiography as is relevant from an endoscopic endonasal perspective.

METHODS

Two hundred MR angiographies of normal subjects were analyzed in a prospective study. The intercarotid distances were measured at fixed points along the paraclival and parasellar segments of the internal carotid artery. The intercarotid spaces thus obtained were categorized into trapezoid, square and hourglass shapes. The angle between the posterior ascending vertical and horizontal bend of the parasellar ICA was also measured and analyzed.

RESULTS

The trapezoid shape of intercarotid space is the most common (52.5%), followed by the square (35%) and the hourglass (12.5%) shaped spaces. Angle of < 80° between the posterior ascending vertical and horizontal bend of the parasellar ICA was found in 39% of subjects, angle between 80° and 100° was found in 9% subjects, angle > 100° was found in 43% while asymmetric angles on the two sides was found in 9% of subjects.

CONCLUSION

A thorough understanding of the course of the ICA is important in planning the approach and preventing injury to the ICA.

Characterization of outcomes and practices utilized in the management of internal carotid artery injury not requiring definitive endovascular management

BACKGROUND

After internal carotid artery (ICA) injury during endoscopic skull base surgery, the majority of patients undergo ICA embolization or stenting to treat active extravasation or pseudoaneurysm development. However, management practices when embolization or stenting is not required have not been well described. The objective of this study was to determine how patients with ICA injury but no embolization, stenting, or ligation do long-term and ascertain the reconstruction methods utilized.

METHODS

Twenty-nine cases of ICA injury were identified in an international multi-institutional retrospective review. Of these, we identified six cases that were not treated with embolization, stenting, or ICA sacrifice. Information was available for five cases.

RESULTS

A muscle patch was used in the immediate repair of each case. A nasoseptal flap was used in one case. Prefabricated nasal tampons were used in all cases. Nasal packing was initially left in for a median of 7 days prior to removal. The initial muscle patch was reinforced with a second muscle graft in one case. One case demonstrated ICA bleeding at the time of packing removal and was repacked an additional week. Follow-up for each of these cases was at least 2 years. No cases of subsequent carotid rupture were found and none of these cases ultimately underwent endovascular stenting. Radiation or proton therapy has not been subsequently used in any of these patients.

CONCLUSIONS

This study details the reconstruction, lessons learned, and long-term follow-up for five cases of ICA injury not treated with embolization, stenting, or ligation.

Identifying Best Practices for Managing Internal Carotid Artery Injury During Endoscopic Endonasal Surgery by Consensus of Expert Opinion

BACKGROUND

Injury to the internal carotid artery (ICA) is a potentially devastating complication of endoscopic endonasal surgery (EES) that as many as 20% of skull base surgeons will experience at least once during their careers. Managing these injuries is difficult given the small operative field and poor visibility created by high-flow hemorrhage, and, at present, there is no consensus regarding best practices.

OBJECTIVE

This study seeks to consolidate the practices and opinions of experienced skull base surgeons from high-volume tertiary care centers into a single consensus statement regarding the best practices for managing ICA injuries during EES.

METHODS

A panel of 23 skull base surgeons (15 neurosurgeons and 8 otolaryngologists) completed a 3-round Delphi survey that assessed experiences and opinions regarding various aspects of ICA injury management. Mean (SD) years since fellowship completion was 15.6 (8.1) and all but 3 surgeons had experienced an ICA injury at least once.

RESULTS

The final consensus statement included 36 guidelines all of which were grouped under 1 of 4 categories: 11 statements concerned preoperative management and equipment for high-risk patients; 14 statements concerned hemorrhage control; 4 statements concerned definitive management; 7 statements concerned pharmacologic treatment, blood pressure, and neurophysiologic monitoring.

CONCLUSIONS

There are numerous decisions that a surgeon must make when facing a carotid artery injury. In our estimation, many questions can be grouped under 1 of the 4 categories outlined in our consensus statement and can be addressed by these findings.

Comparison of compressional and elastic wave simulations for patient-specific planning prior to transcranial photoacoustic-guided neurosurgery

SIGNIFICANCE

Simulations have the potential to be a powerful tool when planning the placement of photoacoustic imaging system components for surgical guidance. While elastic simulations (which include both compressional and shear waves) are expected to more accurately represent the physical transcranial acoustic wave propagation process, these simulations are more time-consuming and memory-intensive than the compressional-wave-only simulations that our group previously used to identify optimal acoustic windows for transcranial photoacoustic imaging.

AIM

We present qualitative and quantitative comparisons of compressional and elastic wave simulations to determine which option is more suitable for preoperative surgical planning.

APPROACH

Compressional and elastic photoacoustic k-Wave simulations were performed based on a computed tomography volume of a human cadaver head. Photoacoustic sources were placed in the locations of the internal carotid arteries and likely positions of neurosurgical instrument tips. Transducers received signals from three previously identified optimal acoustic windows (i.e., the ocular, nasal, and temporal regions). Target detectability, image-based target size estimates, and target-to-instrument distances were measured using the generalized contrast-to-noise ratio (gCNR), resolution, and relative source distances, respectively, for each simulation method.

RESULTS

The gCNR was equivalent between compressional and elastic simulations. The areas of the -6  dB contours of point spread functions utilized to measure resolution differed by 0.33 to 3.35  mm2. Target-to-instrument distance measurements were within 1.24 mm of the true distances.

CONCLUSIONS

These results indicate that it is likely sufficient to utilize the less time-consuming, less memory-intensive compressional wave simulations for presurgical planning.

Sellar and parasellar lesions: multidisciplinary management

Introduction

The endoscopic endonasal transsphenoidal approach to the sella and parasellar regions is now increasingly used for removal of a variety of lesions localized in the ventral skull base. The advantage of the endoscope is enhanced visualization and improved panoramic view that can result in more complete removal of the tumor. An extensive knowledge of the anatomy is mandatory to approach this region.

Materials and methods

From February 2009 to March 2020, the endoscopic endonasal approach was used in 153 patients with sellar and parasellar lesions, at our Institution: 136 pituitary adenomas, 7 craniopharyngiomas, 3 Rathke’s cysts, a tuberculum sellae meningioma, an aneurysm of the internal carotid artery (ICA), a clivus chordoma, a papillary glioneuronal tumor, an histiocytosis, a pituitary metastasis from breast cancer and a chondrosarcoma.

Results

The most common surgical complications were cerebral spinal fluid leak (9), bleeding (2), pituitary abscess (2). Among endocrinological complications, the most important were diabete insipidus (23) and panhypopituitarism (3). Two patients complicated with meningitis. There were no visual worsening and no operative mortality. We had persistence of disease in 20 cases. Twelve patients underwent surgical revision for recurrence of the disease.

Conclusions

Pre-operative planning and collaboration with several specialists are necessary in order to offer the patient the best treatment, minimizing complications.

Inadvertent internal carotid artery (ICA) injury during transsphenoidal surgery: review of literature

Background

Internal carotid artery (ICA) injury is a hazardous catastrophe for the skull base surgery team. We aimed to illustrate the vital joints in this hazardous event during endoscopic surgery.

Main text

The condition is rare (1.1%) but fatal per se. Working in the field of endoscopic surgery is not free of charges. It demands a thorough knowledge of anatomy, variations, and pathoanatomy to expect what can be seen thereafter. Once the injury occurs, one must have a quite clear plan to proceed. Marvelous bleeding is confusing not only in the field but also in the mind process.

Conclusion

Endoscope teams when expose to this event should think in a stepwise manner. In our review, we explained the pathoanatomy of the field after an injury, pre-conditions of injury, and how to avoid certain drawbacks during management.

Incidence and Management of Delayed Epistaxis Following Endoscopic Skull Base Surgery

Objective:

Among other complications of endoscopic skull base surgery, delayed epistaxis has not been given much importance. This report presents postoperative delayed nosebleed cases in a large number of patients who underwent an endoscopic endonasal transsphenoidal approach to the sellar region for resection of lesions.

Methods:

Three hundred and sixty three patients who were reached to the sellar region by endoscopic endonasal transsphenoidal route and operated was included in the study. Retrospective chart reviewing of these patients was performed. The correlation between the duration of nosebleeds, bleeding location, treatment methods and comorbidities of the patients were evaluated.

Results:

Ten patients (3.6%) reported delayed epistaxis in the postoperative period and were referred to the otolaryngology department. Postoperative epistaxis occurred between days 7^th and 33^th (mean 16.5) days. The treatment consisted of chemical silver nitrate cauterization in two patients, return to the operating room in three patients, nasal packing in five patients.

Conclusion:

Delayed postoperative epistaxis often has no obvious etiology, and intervention requires teamworking. Well-coordinated teamworking of the neurosurgeon with other specialities such as neuroradiology and otorhinolaryngology is needed to achieve better results.

Repair of internal carotid artery injury with aneurysm clip during endoscopic endonasal surgery: illustrative case

BACKGROUND

One of the most feared and dangerous scenarios that can appear during an endoscopic endonasal surgery (EES) is the iatrogenic injury of the internal carotid artery (ICA). Several methods, along with a variety of outcomes, have been described to deal with this complication. To the authors’ knowledge, this is the first report on the use of a Yasargil-type aneurysm clip to solve an ICA injury, preserving the artery’s patency and having a long-term follow-up. The authors discuss the advantages and disadvantages of other vessel preservation techniques compared with clipping.

OBSERVATIONS

A visually impaired 56-year-old woman was diagnosed with a giant nonfunctional pituitary tumor that invaded the sphenoidal sinus, anterior and posterior ethmoidal cells, and both cavernous sinuses, with suprasellar extension and optochiasmatic compression. The patient underwent EES, and during the final resection phase her left ICA was injured, with massive hemorrhage.

LESSONS

ICA injury during endoscopic skull base surgery carries high mortality and morbidity; it is essential to maintain carotid flow when possible to avoid short-term and long-term consequences. There are several techniques depicted in the literature to deal with this situation. The authors report the use of a Yasargil mini-clip to deal with the injury for a positive outcome: primary hemostasis, vessel preservation, and no postoperative complications.

Assessment of Factors Associated With Internal Carotid Injury in Expanded Endoscopic Endonasal Skull Base Surgery

Importance

Injury to the internal carotid artery (ICA) during endoscopic endonasal skull base surgery does not typically occur as an isolated circumstance but often is the result of multiple factors.

Objective

To assess the factors associated with ICA injury in an effort to reduce its occurrence.

Design, Setting, and Participants

This quality improvement study used a multicenter root cause analysis of ICA injuries sustained during endoscopic endonasal skull base surgery performed at 11 tertiary care centers across 4 continents (North America, South America, Europe, and Asia) from January 1, 1993, to December 31, 2018. A fishbone model was built to facilitate the root cause analysis. Patients who underwent an expanded endoscopic endonasal approach that carried a substantial potential risk of an ICA injury were included in the analysis. A questionnaire was completed by surgeons at the centers to assess relevant human, patient, process, technique, instrument, and environmental factors associated with the injury.

Main Outcomes and Measures

Root cause analysis of demographic, human, patient, process, technique, instrument, and environmental factors as well as mortality and morbidity data.

Results

Twenty-eight cases of ICA injury occurred during 7160 expanded endoscopic endonasal approach procedures (incidence of 0.4%). The mean age of the patients was 49 years, with a female to male predominance ratio of 1.8:1 (18 women to 10 men). Anatomical (23 [82%]), pathological (15 [54%]), and surgical resection (26 [93%]) factors were most frequently reported. The surgeon's mental or physical well-being was reported as inadequate in 4 cases (14%). Suboptimal imaging was reported in 6 cases (21%). The surgeon's experience level was not associated with ICA injury. The ICA injury was associated with use of powered or sharp instruments in 20 cases (71%), and use of new instruments or technology in 7 cases (25%). Two patients (7%) died in the operating room, and 3 (11%) were alive with neurological deficits. Overall, patient-related factors were the most frequently reported risk factors (in 27 of 28 cases [96%]). Factors associated with ICA injury catalyzed a list of preventive recommendations.

Conclusions and Relevance

This study found that human factors were associated with intraoperative ICA injuries; however, they were usually accompanied by other deficiencies. These findings suggest that identifying risk factors is crucial for preventing such injuries. Preoperative planning and minimizing the potential for ICA injury also appear to be essential.

Classification of internal carotid artery injuries during endoscopic endonasal approaches to the skull base

Background:

Internal carotid artery (ICA) injuries are a major complication of endoscopic endonasal approaches (EEAs), which can be difficult to manage. Adding to the management difficulty is the lack of literature describing the surgical anatomical classification of these types of injuries. This article proposing a novel classification of ICA injuries during EEAs.

Methods:

The classification of ICA injuries during EEAs was generated from the review of the literature and analysis of the main author observation of ICA injuries in general. All published cases of ICA injuries during EEAs in the literature between January 1990 and January 2020 were carefully reviewed. We reviewed all patients’ demographic features, preoperative diagnoses, modes of injury, cerebral angiography results, surgical and medical management techniques, and reported functional outcomes.

Results:

There were 31 papers that reported ICA injuries during EEAs in the past three decades, most studies did not document the type of injury, and few described major laceration type of it. From that review of the literature, we classified ICA injuries into three main categories (Types I-III) and six sub-types. Type I is ICA branch injury, Type II is a penetrating injury to the ICA, and Type III is a laceration of the ICA wall. The functional neurological outcome was found to be worse with Type III and better with Type I.

Conclusion:

This is a novel classification system for ICA injuries during EEAs; it defines the patterns of injury. It could potentially lead to advancements in the management of ICA injuries in EEAs and facilitate communication to develop guidelines.

Nasopharyngeal muscle patch for the management of internal carotid artery injury in endoscopic endonasal surgery

OBJECTIVE

Injury to the internal carotid artery (ICA) is the most critical complication of endoscopic endonasal skull base surgery. Packing with a crushed muscle graft at the injury site has been an effective management technique to control bleeding without ICA sacrifice. Obtaining the muscle graft has typically required access to another surgical site, however. To address this concern, the authors investigated the application of an endonasally harvested longus capitis muscle patch for the management of ICA injury.

METHODS

One colored silicone-injected anatomical specimen was dissected to replicate the surgical access to the nasopharynx and the stepwise dissection of the longus capitis muscle in the nasopharynx. Two representative cases were selected to illustrate the application of the longus capitis muscle patch and the relevance of clinical considerations.

RESULTS

A suitable muscle graft from the longus capitis muscle could be easily and quickly harvested during endoscopic endonasal skull base surgery. In the illustrative cases, the longus capitis muscle patch was successfully used for secondary prevention of pseudoaneurysm formation following primary bleeding control on the site of ICA injury.

CONCLUSIONS

Nasopharyngeal harvest of a longus capitis muscle graft is a safe and practical method to manage ICA injury during endoscopic endonasal surgery.

Use of Adenosine to Facilitate Localization and Repair of Internal Carotid Artery Injury during Skull Base Surgery: A Case Report and Literature Review

BACKGROUND

Internal carotid artery (ICA) injuries represent a rare, potentially fatal complication of endoscopic endonasal skull base surgery (EESBS). The use of adenosine to induce transient hypotension and facilitate management of high-flow, high-pressure arterial lesions has been well-documented in neuro-endovascular literature. A similar setting in which adenosine-induced hypotension may prove beneficial is during the management of major vascular injury encountered during EESBS.

METHODS

A case of ICA injury and subsequent repair during EESBS is presented.

RESULTS

A 74-year-old female underwent endoscopic transsphenoidal resection for a recurrent pituitary adenoma. During suprasellar resection, the right cavernous ICA was inadvertently injured resulting in brisk bleeding. Immediate vascular tamponade was applied, and a crushed muscle graft was obtained. Two intravenous doses of adenosine were administered in quick succession to produce transient hypotension and facilitate repair of the injury with the graft. Neurovascular imaging revealed a small pseudoaneurysm which remained stable throughout the postoperative course. The patient underwent definitive stent embolization of the pseudoaneurysm 1 month following discharge.

CONCLUSION

Prompt repair of ICA injury during EESBS is crucial, but often limited by poor visualization. Adenosine-induced hypotension has demonstrated great efficacy as an adjuvant in neurovascular clipping of intracranial aneurysms and remains a valuable tool for the endoscopic skull-base surgeon as well. In cases with high risk for ICA injury, adenosine should be readily available.

Internal carotid artery injury in the endoscopic transsphenoidal surgery for pituitary adenoma: an uncommon case and literature review

Complications of the transsphenoidal surgery (TSS) for pituitary adenoma (PA) include vascular injury, nerve injury and nervous system infection. Among these, the consequences of internal carotid artery (ICA) injury are the most serious, and its mortality and disability rates are very high. The TSS was used in 889 patients with PA, among which there was 1 case of ICA injury. In this uncommon case of bromocirptine-resistant macro-prolatinoma, the patient had received an ultrahigh dose of oral bromocriptine for almost three years and was intraoperatively found to have a tenacious tumor texture and close adhesion of the tumor capsule to the ICA. Resection of the tumor capsule required excessive force, resulting in the rupture at the A1 origin of the left ICA. Endovascular balloon occlusion was used after urgent angiography. The patient died in two weeks even with intensive treatment. Although the underlying mechanism is still obscure, bromocriptine-inducing tumor fibrosis in PA is relatively common. For these patients with excessive dose of bromocriptine, tumor fibrosis and ICA injury should be seriously considered and performing a complete preoperative imaging evaluation to achieve accurate intraoperative positioning and carefully performing the operation are needed to preventing ICA injury. In some cases, resection of the tumor pseudocapsule should not be forced to avoid ICA injury.

Endovascular reconstruction of iatrogenic internal carotid artery injury following endonasal surgery: a systematic review

The objective of this study is to provide an update on endovascular treatments for iatrogenic internal carotid artery (ICA) injuries following endonasal surgery. A systematic review of the literature was performed by using Medline, Cochrane library, and Scopus from 1999 to 2019. We used a combination of the MeSH terms "internal carotid artery," "iatrogenic disease," and "endovascular procedure." Twenty-six articles including 46 patients were identified for in this systematic review. The mean age of the patients was 49 years (CI: ± 4.2). The most common site of ICA injury was in cavernous segment (18 patients; 39%). The most common type of iatrogenic ICA injury was a traumatic pseudoaneurysm documented in 28 patients (60%). Endoluminal reconstruction was performed using covered stents in 28 patients, the Pipeline embolization device (PED) in 13 patients, the Surpass flow diverter device in three, the SILK flow diverter in one, and one case was treated using a combined approach of a covered stent and a PED. Flow diversion and covered stents resulted in a good clinical outcome in 94% and 89% of patients, respectively. This difference did not reach statistical significance (p = 1.0). Even though this systematic review was limited due to articles of small sample sizes and considerable heterogeneity, the results indicate that flow diverting devices and covered stents are good therapeutic options for endoluminal reconstruction of iatrogenic ICA injuries following endonasal surgery.

Rupture from cavernous internal carotid artery pseudoaneurysm 11 years after transsphenoidal surgery

Carotid artery pseudoaneurysm is a rare complication of transsphenoidal surgery, usually diagnosed within 90 days post procedure. Sequelae of pseudoaneurysm rupture, such as severe epistaxis or carotid cavernous fistula (CCF), have significant morbidity and mortality. A case of epistaxis from pseudoaneurysm rupture over a decade after transsphenoidal surgery is presented, with staged treatment using coiling, endonasal mucosal flap repair and interval flow-diverting stent insertion. This case illustrates that pseudoaneurysm rupture occurs regardless of time course after transsphenoidal surgery, and treatment strategies using combined endovascular and endonasal techniques are reviewed.

Photoacoustic imaging for surgical guidance: Principles, applications, and outlook

Minimally invasive surgeries often require complicated maneuvers and delicate hand-eye coordination and ideally would incorporate "x-ray vision" to see beyond tool tips and underneath tissues prior to making incisions. Photoacoustic imaging has the potential to offer this feature but not with ionizing x-rays. Instead, optical fibers and acoustic receivers enable photoacoustic sensing of major structures-such as blood vessels and nerves-that are otherwise hidden from view. This imaging process is initiated by transmitting laser pulses that illuminate regions of interest, causing thermal expansion and the generation of sound waves that are detectable with conventional ultrasound transducers. The recorded signals are then converted to images through the beamforming process. Photoacoustic imaging may be implemented to both target and avoid blood-rich surgical contents (and in some cases simultaneously or independently visualize optical fiber tips or metallic surgical tool tips) in order to prevent accidental injury and assist device operators during minimally invasive surgeries and interventional procedures. Novel light delivery systems, counterintuitive findings, and robotic integration methods introduced by the Photoacoustic & Ultrasonic Systems Engineering Lab are summarized in this invited Perspective, setting the foundation and rationale for the subsequent discussion of the author's views on possible future directions for this exciting frontier known as photoacoustic-guided surgery.

Nasal Packing Causing Occlusion of Contralateral Internal Carotid Artery During Control of Pseudoaneurysm Bleed

BACKGROUND

Carotid pseudoaneurysm is a rare complication of pituitary surgery and can present with epistaxis. Nasal packing is considered first-line treatment for the control of carotid bleeding. We describe a case of complete occlusion of the contralateral cavernous carotid artery because of nasal packing placed to control hemorrhage from a cavernous carotid pseudoaneurysm.

CASE DESCRIPTION

A 55-year-old man presented with a history of recurrent epistaxis requiring multiple hospital visits and nasal packing over a 9-month period. Nasal endoscopies failed to show a source of bleeding; therefore, the patient underwent bilateral sphenopalatine artery ligations. Postoperative computed tomography angiogram showed no evidence of aneurysm, but did report indistinctness of the lateral sphenoid walls. Symptoms remained controlled for 4 months, but ultimately, he presented to the emergency department with massive epistaxis. A magnetic resonance angiogram noted a 2- to 3-mm left cavernous carotid pseudoaneurysm, and the patient underwent endovascular embolization of bilateral internal maxillary arteries. Significant epistaxis was noted immediately thereafter and he was taken to the operating room to control bleeding. A 4-cm absorbable nasal packing was placed into each sphenoid cavity after profuse bleeding from the left sphenoid sinus was noted. After control of bleeding, cerebral angiogram showed complete occlusion of bilateral internal carotid arteries (ICAs). The right-sided packing was adjusted, and the ICA profusion improved.

CONCLUSIONS

To our knowledge, this is the only report that describes complete occlusion of the contralateral cavernous carotid artery because of extrinsic compression of the lateral sphenoid wall, in the setting of a symptomatic pseudoaneurysm.

Sphenoid sinus septations and their interconnections with parasphenoidal internal carotid artery protuberance: radioanatomical study with literature review

Introduction

Internal carotid artery (ICA) injury is the most dangerous and life-threatening complication in patients operated on due to parasellar tumors via a minimally invasive endoscopic endonasal approach. Sphenoid septal attachment to the ICA protuberance within the sphenoid sinus was found to be one of the anatomical risk factors for ICA injury during transsphenoidal surgery.

Aim

To determine the relationship between the sphenoid sinus septa and the parasellar or paraclival internal carotid artery prominence based on our own material and a literature review.

Material and methods

The axial plane scans of computed tomography angiography and a literature review of previously published papers on the septum variation and its connection with the ICA prominence are provided.

Results

Out of 100 sphenoid sinuses, 49 (49%) had at least one septum inserted at the ICA prominence. In the majority of cases 42 (86%) one septum was inserted at the prominence of one of the ICAs. In 7 (14%) cases, two separate septa were inserted at the prominences of both ICAs. Patients with multiple septa and those having an incomplete septum were at higher risk of at least one of them being inserted at the ICA prominence within the sinus. Including cases from the literature review, the average number of septa per patient was 1.42. The risk of intersection between the septum and the ICA prominence was 32%.

Conclusions

A significant percentage of the intrasphenoidal septa are inserted at the sphenoidal ICA protuberance.

Internal carotid artery injury during endonasal sinus surgery: our experience and review of the literature

Iatrogenic internal carotid artery injury is a catastrophic but uncommon complication of endonasal sinus surgery. We present our experience in managing this emergency situation. A 52-year-old man underwent revision endoscopic repair of recurrent cerebrospinal fluid leak that was complicated with profuse haemorrhage during removal of the anterior wall of sphenoid sinus using a Hajek sphenoid punch forceps. Immediate packing of the sphenoid sinus controlled the haemorrhage. Urgent angiography revealed injury at the paraclival segment of the left internal carotid artery. An endovascular stent was initially placed but thrombosed; it was subsequently converted to coil embolisation. The patient had watershed cerebral infarct with hemiparesis post procedure but made full recovery within 6 weeks. Immediate nasal packing followed by urgent angiography and endovascular stent placement is the least invasive definitive treatment. If stenting is unsuccessful, endovascular balloon occlusion or coil embolisation is the next preferred treatment, if there is adequate cross-cerebral circulation. The success of treatment relies on its immediate management by a multidisciplinary team.

Avoiding complications in endoscopic skull base surgery

PURPOSE OF REVIEW

Endoscopic skull base surgery has become an established approach for the removal of tumors and cerebrospinal fluid fistulae repair. Compared with external approaches, it provides better aesthetic results and quality of life postoperatively. However, as it becomes popular and expands its indications possible complications should be reassessed in terms of incidence and variability in order to confirm its efficacy and safety. This article reviews the recent literature describing the main categories of possible complications suggesting strategies to minimize their incidence.

RECENT FINDINGS

Detailed preoperative planning based on imaging and histology can prevent major complications. Intraoperative use of image guidance and meticulous hemostasis provide the surgical field needed to avoid complications. Postoperative patient counseling, along with close and detailed nasal postoperative care are significant factors for an optimal outcome.

SUMMARY

Monitoring of complications after endoscopic skull base surgery is necessary in order to standardize protocols of management and improve our surgical techniques. The presence of late onset complications underlines the need of a special focus in postoperative care and follow-up.

Usefulness of Oblique Coronal Computed Tomography and Magnetic Resonance Imaging in the Endoscopic Endonasal Approach to Treat Skull Base Lesions

OBJECTIVE

This report examines the usefulness of the preoperative image to orient the surgeon in the sphenoid sinus during endoscopic endonasal transsphenoidal surgery (ETSS).

METHODS

ETSS was performed in 100 cases of sellar lesion and used to classify the sphenoid sinus septum shape. Preoperative computed tomography and magnetic resonance imaging were performed for 2 types of coronal imaging: conventional and oblique. Expected sphenoid sinus septum shape was compared with those from ETSS to estimate concordance. The confirmation rate of anatomic landmarks in the sphenoid sinus by endoscopic observation was compared in various types of septum and the identification rate in oblique coronal imaging was also examined.

RESULTS

The most common septum shape was single type (31%), followed by branched (26%), parallel (18%), none (12%), cross (9%), and bridge (4%) types. In oblique coronal images, preoperative evaluation and endoscopic findings were consistent in 93%-100% of cases. However, with conventional coronal images, the concordance rate was 22.2%-83.9%, and in the none, branched, and cross types, the concordance rate was significantly lower than that for oblique coronal images. Although confirmation of the midline through estimation of landmarks by endoscopic observation was difficult in 33 cases, preoperative computed tomography and magnetic resonance imaging showed landmarks in all cases and oblique coronal images best indicated the midline.

CONCLUSIONS

Use of oblique coronal images in addition to conventional images provided good orientation of anatomic structures in the sphenoid sinus. The combination of preoperative imaging and endoscopic observation could allow safer surgery in ETSS.

Injury of the Carotid Artery during Endoscopic Endonasal Surgery: Surveys of Skull Base Surgeons

Objectives  This study aimed to review endoscopic skull base surgeon experience with internal carotid artery (ICA) injuries during endoscopic endonasal surgery (EES) to provide an estimate of the incidence of ICA injury, the associated factors and identify the best training modalities for the management of this complication. Design  Anonymous electronic survey of past participants at a well-established endoscopic skull base surgery course and a global online community of skull base surgeons. Main Outcome Measures  Relative incidence of ICA injuries during EES, associated anatomic and intraoperative factors, and surgeon experience. Results  At least 20% of surgeons in each surveyed population experienced a carotid artery injury. Reported carotid artery injuries were most common during tumor exposure and removal (48%). The parasellar carotid artery was the most commonly injured segment (39%). Carotid artery injuries were more common in high-volume surgeons, but only statistically significant in one of the two populations. Attendance at a skull base course or courses did not change the incidence of carotid artery injury in either surveyed population. In both surveys, respondents preferred live surgeries or active (not computer simulated) training models. Conclusions  ICA injury is underreported and most common when manipulating the parasellar carotid artery for exposure and tumor dissection. Given the high morbidity and mortality associated with these injuries, vascular injury management should be prioritized and taught in a graduated approach by modern endoscopic skull base courses.

Simulating Internal Carotid Artery Injury during Transsphenoidal Transclival Endoscopic Surgery in a Perfused Cadaver Model

Introduction  Managing internal carotid artery (ICA) injury during extended endoscopic transsphenoidal surgery is an extreme challenge. We aimed to find a possible surgical treatment strategy. Methods  We operated seven fresh, perfused cadaver heads with a transsphenoidal endoscopic approach of the ICA using a three-dimensional-high definition (3D-HD) endoscope. We made a paraclival ICA leak, which we tried to manage with clips and microsutures. Results  Accurate transsphenoidal clip application on the ICA was impossible with standard aneurysm clips and applier. It was only feasible with a 9 mm slightly bended clip that could be opened from the inside and be applied with a dedicated flexible thin applier. Transsphenoidal suturing of an ICA leak was impossible from the ipsilateral nostril or with standard microinstruments. Suturing was only feasible from the contralateral nostril using flexible microinstruments with a thin 90-mm shaft. This was technically very challenging and involved a steep learning curve. Conclusion  Tamponade with muscle or fat and a quick transfer to the angiography suite for endovascular control remains the preferable option in case of an ICA leak during endoscopic transsphenoidal surgery. If tamponade gives insufficient initial control, ICA clipping could be possible with dedicated instruments, with risk of increasing the defect, stenosis, or occlusion of the vessel. Transsphenoidal ICA suturing remains extremely difficult, and laboratory practice seems essential.

Platelet activation by crushed and uncrushed muscle: a flow cytometry analysis

BACKGROUND

Crushed autologous muscle is used in skull base surgery in the acute phase of major arterial hemorrhage to stop bleeding. The mechanism of this is not yet clear, but is thought to involve the formation of a platelet plug, which seals the vessel wall defect but still allows ongoing blood flow to the brain.

METHODS

In this study we use flow cytometry to replicate the in-vivo actions of crushed muscle on platelets in whole blood. We compare the ratio of activation of platelets exposed to crushed and uncrushed muscle supernatant in control patients and in patients on antiplatelet agents.

RESULTS

Crushed muscle activated platelets to a higher degree than uncrushed muscle: 5.18-fold greater in control blood (p = 0.002); 6.53-fold greater in aspirin-exposed blood (p < 0.0001); and 9.4-fold greater in clopidogrel-exposed blood (p < 0.0001).

CONCLUSION

Crushed muscle caused a consistently increased ratio of platelet activation when compared with uncrushed muscle across all groups, adding to the evidence that at least part of its clinical effect is the result of platelet activation.

Nano-hemostats and a Pilot Study of Their Use in a Large Animal Model of Major Vessel Hemorrhage in Endoscopic Skull Base Surgery

Nano-hemostats are synthetic amino acid chains that self-assemble into a scaffold under certain conditions. These have been shown to be effective in stopping bleeding in small animal models of hemorrhage. Proposed mechanisms for their effect are that they form a mesh analogous to the fibrin plug in native hemostasis and that they may potentiate both platelet activation and the coagulation cascade. These may potentially become valuable adjuncts to endoscopic skull base surgery where there is the potential for both major vessel injury and smaller perforator injury to eloquent areas where bipolar cautery may not be suitable. We present a summary of the clinical studies to date and a small pilot study of nano-hemostat in an endoscopic sheep model of major vessel hemorrhage to determine its efficacy in stopping bleeding in this potentially catastrophic complication.

Simulation Training for Vascular Emergencies in Endoscopic Sinus and Skull Base Surgery

Carotid artery injury during endonasal surgery is a feared and potentially catastrophic complication. Simulation training provides the opportunity for a realistic experience with management of major vascular injuries. The sheep model of carotid artery injury reproduces the challenges of dealing with vascular emergencies during endoscopic sinus and skull base surgery, which include working in narrow nasal confines, high-flow/high-pressure vascular injury, and the immediately challenging surgical field. Simulated vascular emergencies allow for research and development; training using various surgical techniques to control the field, including hemostatic products or direct vascular closure techniques; and consequently improved patient care and outcomes.

Management of Major Vascular Injury: Open

Major blood vessels are in proximity to other vital structures in the neck and base of skull. Infections and tumors of the head and neck can invade vascular structures. Vascular injuries can lead to massive hemorrhage, cerebral ischemia, or stroke. Emergency and definitive management can be challenging.

Management of arterial injury during endoscopic sinus and skull base surgery

PURPOSE OF REVIEW

The most feared complication during endonasal surgery is a carotid artery injury. The sheep model of carotid injury provides training for this event by giving a realistic endoscopic experience of major vascular injuries and tissue hemostasis.

RECENT FINDINGS

The sheep model of carotid artery injury recreates the narrow nasal confines and high-flow/high-pressure vascular injury accurately reproducing the endoscopic challenges seen in such vascular emergencies. This has led to the development of surgical techniques that quickly and effectively control the field of bleeding and achieve reliable hemostasis including the crushed muscle patch new direct vascular closure technologies. Vascular emergency simulation training is achieving better outcomes for our patients.

SUMMARY

All skull base surgeons are at risk of the unexpected carotid artery injury and recently, the sheep model not only effectively recreates this situation but has identified clinically tried and tested techniques at managing this situation and is improving patient outcomes.

Different Perspectives of Internal Carotid Artery in Transnasal Endoscopic Surgery

BACKGROUND

Several endoscopic landmarks for the internal carotid artery (ICA) have been identified, but they have always been proposed in a "static" perspective. The aim of this study was to investigate how the surgical corridor and optical distortion can influence the perception of carotid landmarks in transnasal endoscopic surgery.

METHODS

Computed tomography images of skulls in 20 subjects were analyzed. The petrous carotid angle (PCA) was calculated as the angle between the petrous carotid axis and the coronal plane connecting stylomastoid foramina. The angle of incidence (AI) on the anterior carotid genu of 3 different surgical corridors (contralateral nostril, ipsilateral nostril, and transmaxillary ipsilateral route) was evaluated. PCA, AI, and their differences were studied by Spearman's correlation test. Two cadaver heads were dissected, simulating the studied surgical corridors. The fish-eye effect was empirically quantified.

RESULTS

Mean PCA was 31° (range, 21-41°). PCA and AI are linked by an inverse proportion relationship. A transmaxillary approach always ensures the highest value of AI on the target. The cadaveric dissection qualitatively confirmed the radiologic data. The fish-eye effect can cause a compression of distance perception as high as 37%.

CONCLUSIONS

The surgical corridor and endoscope optic distortion can influence ICA visualization and the perception of its anatomic landmarks. In a 2-nostril, 4-handed approach, it is advisable to place the endoscope and instrument for dissection in the nostril that is ipsilateral to the lesion. Awareness of the different perspectives and related optical distortions is essential when working in proximity to the ICA.

Hemorrhagic Complications of Endoscopic Sinus Surgery

Major complications during endoscopic sinus surgery are rare and occur in 0.36% to 3.1% of patients. Postoperative hemorrhage accounts for 23% to 39% of complications. Despite being rare, major hemorrhage can be serious for the patient. This article discusses hemorrhagic complications during and following endoscopic sinus surgery, focusing on a review of the surgical anatomy, common pitfalls to avoid, preventative measures, and management of certain catastrophic complications for which preparedness can mean the difference between life and death.