- •Foreword
- •Preface
- •Acknowledgments
- •Contents
- •Contributors
- •1.2 Forehead Augmentation
- •1.2.1 Discussion
- •1.3.1 Discussion
- •1.4 Rhinoplasty
- •1.4.1 Discussion
- •1.5 Lip Augmentation
- •1.5.1 Discussion
- •1.6 Chin and Jaw Augmentation
- •1.6.1 Discussion
- •Further Reading
- •Forehead Augmentation
- •Rhinoplasty
- •Lip Augmentation
- •Jaw Augmentation
- •2: Imaging the Postoperative Orbit
- •2.1 Eyelid Weights
- •2.1.1 Discussion
- •2.2 Palpebral Springs
- •2.2.1 Discussion
- •2.3.1 Discussion
- •2.4.1 Discussion
- •2.5.1 Discussion
- •2.6.1 Discussion
- •2.7 Strabismus Surgery
- •2.7.1 Discussion
- •2.8 Glaucoma Surgery
- •2.8.1 Discussion
- •2.9 Scleral Buckles
- •2.9.1 Discussion
- •2.10 Keratoprostheses
- •2.10.1 Discussion
- •2.11 Intraocular Lens Implants
- •2.11.1 Discussion
- •2.12 Surgical Aphakia
- •2.12.1 Discussion
- •2.13 Pneumatic Retinopexy
- •2.13.1 Discussion
- •2.14 Intraocular Silicone Oil
- •2.14.1 Discussion
- •2.15.1 Discussion
- •2.16 Orbital Tissue Expanders
- •2.16.1 Discussion
- •2.17 Orbital Exenteration
- •2.17.1 Discussion
- •2.18.1 Discussion
- •Further Reading
- •Eyelid Weights
- •Palpebral Spring
- •Frontalis Suspension Ptosis Repair
- •Strabismus Surgery
- •Glaucoma Surgery
- •Scleral Buckles
- •Keratoprostheses
- •Intraocular Lens Implants
- •Surgical Aphakia
- •Pneumatic Retinopexy
- •Intraocular Silicone Oil
- •Orbital Tissue Expanders
- •Orbital Exenteration
- •3.1.1 Discussion
- •3.2 Septoplasty
- •3.2.1 Discussion
- •3.3.1 Discussion
- •3.4.1 Discussion
- •3.5 Nasal Packing Material
- •3.5.1 Discussion
- •3.6 Rhinectomy
- •3.6.1 Discussion
- •3.7 Sinus Lift Procedure
- •3.7.1 Discussion
- •3.8 Caldwell-Luc Procedure
- •3.8.1 Discussion
- •3.9 External Ethmoidectomy
- •3.9.1 Discussion
- •3.10.1 Discussion
- •3.11 FESS Complications
- •3.11.1 Discussion
- •3.11.2 Discussion
- •3.11.3 Discussion
- •3.11.4 Discussion
- •3.11.5 Discussion
- •3.11.6 Discussion
- •3.11.7 Discussion
- •3.11.8 Discussion
- •3.11.9 Discussion
- •3.11.10 Discussion
- •3.11.11 Discussion
- •3.12 Osteoplastic Flap with Frontal Sinus Obliteration
- •3.12.1 Discussion
- •3.13 Frontal Sinus Cranialization
- •3.13.1 Discussion
- •3.14 Paranasal Sinus Stents
- •3.14.1 Discussion
- •3.15 Frontal Sinus Trephination
- •3.15.1 Discussion
- •3.16.1 Discussion
- •3.17.1 Discussion
- •3.18 Maxillary Swing
- •3.18.1 Discussion
- •Further Reading
- •Septoplasty
- •Nasal Septal Button Prosthesis
- •Nasal Packing Material
- •Rhinectomy
- •Sinus Lift
- •Caldwell-Luc Procedure
- •External Ethmoidectomy
- •Functional Endoscopic Sinus Surgery
- •FESS Complications
- •Osteoplastic Flap with Frontal Sinus Obliteration
- •Frontal Sinus Cranialization
- •Paranasal Sinus Stents
- •Frontal Sinus Trephination
- •Maxillectomy and Palatectomy
- •Maxillary Swing
- •4.1 Occipital Nerve Stimulator
- •4.1.1 Discussion
- •4.2 Tissue Expander
- •4.2.1 Discussion
- •4.3 Temporal Fossa Implants
- •4.3.1 Discussion
- •4.4.1 Discussion
- •4.5.1 Discussion
- •4.6.1 Discussion
- •4.7 Scalp Tumor Recurrence
- •4.7.1 Discussion
- •4.8 Burr Holes
- •4.8.1 Discussion
- •4.9 Craniotomy
- •4.9.1 Discussion
- •4.10 Cranioplasty
- •4.10.1 Discussion
- •4.11 Autocranioplasty
- •4.11.1 Discussion
- •4.12.1 Discussion
- •4.14.1 Discussion
- •4.15 Box Osteotomy
- •4.16.1 Discussion
- •4.17.1 Discussion
- •4.18.1 Discussion
- •4.19 Subdural Drainage Catheters
- •4.19.1 Discussion
- •4.20.1 Tension Pneumocephalus
- •4.20.5 Pseudomeningoceles
- •4.20.6 Pseudoaneurysm
- •4.20.7 Postoperative Infection
- •4.20.8 Textiloma
- •4.20.9 Sunken Skin Flap Syndrome
- •4.20.10 External Brain Herniation
- •4.20.11 Bone Flap Resorption
- •Further Reading
- •Occipital Nerve Stimulator
- •Tissue Expander
- •Temporal Fossa Implant
- •Scalp Tumor Recurrence
- •Box Osteotomy
- •Absorbable Hemostatic Agents
- •Duraplasty and Sealant Agents
- •Burr Holes
- •Craniotomy
- •Cranioplasty
- •Autocranioplasty
- •Cranial Vault Reconstruction for Craniosynostosis
- •Cranial Vault Encephalocele Repair
- •Subdural Drainage Catheters
- •Intracranial Pressure Monitor
- •Cranial Surgery Complications
- •5.1 Intraoperative MRI
- •5.1.1 Discussion
- •5.2.1 Stereotactic Biopsy
- •5.2.1.1 Discussion
- •5.2.2 Resection Cavities
- •5.2.2.1 Discussion
- •5.2.3 Ommaya Reservoirs
- •5.2.3.1 Discussion
- •5.2.4 Chemotherapy Wafers
- •5.2.4.1 Discussion
- •5.2.5 Brachytherapy Seeds
- •5.2.5.1 Discussion
- •5.2.6.1 Discussion
- •5.3.1 Prefrontal Lobotomy
- •5.3.1.1 Discussion
- •5.3.2 Pallidotomy
- •5.3.2.1 Discussion
- •5.3.3 Cingulotomy
- •5.3.3.1 Discussion
- •5.3.4.1 Discussion
- •5.3.4.2 Thalamotomy
- •5.3.5 Deep Brain Stimulation (DBS)
- •5.3.5.1 Discussion
- •5.3.6.1 Discussion
- •5.3.7.1 Discussion
- •5.3.8.1 Discussion
- •5.3.9.1 Discussion
- •5.3.10 Corticectomy
- •5.3.10.1 Discussion
- •5.3.11.1 Discussion
- •5.3.12.1 Discussion
- •5.3.13 Callosotomy
- •5.3.13.1 Discussion
- •5.3.14 Anterior Temporal Lobectomy
- •5.3.14.1 Discussion
- •5.3.15.1 Discussion
- •5.3.16 Hemispherectomy
- •5.3.16.1 Discussion
- •Further Reading
- •Intraoperative MRI
- •Brain Tumor Surgery
- •Stereotactic Biopsy
- •Resection Cavities
- •Postoperative Hemorrhagic Lesions
- •Ommaya Reservoirs
- •Chemotherapy Wafers
- •Brachytherapy Seeds
- •GliaSite Radiation Therapy System
- •Prefrontal Lobotomy
- •Pallidotomy
- •Cingulotomy
- •Thalamotomy
- •Deep Brain Stimulation (DBS)
- •Epidural Motor Cortex Stimulator
- •Neural Interface System (BrainGate)
- •Corticectomy
- •Selective Disconnection
- •Callosotomy
- •Anterior Temporal Lobectomy
- •Hemispherectomy
- •6.1 Types of Procedures
- •6.1.1 External Ventricular Drainage
- •6.1.1.1 Discussion
- •6.1.2.1 Discussion
- •6.1.3 Atypical Ventricular Shunts
- •6.1.3.1 Discussion
- •6.1.4 Ventriculosubgaleal Shunts
- •6.1.4.1 Discussion
- •6.1.5.1 Discussion
- •6.1.6.1 Discussion
- •6.1.7 Subdural-Peritoneal Shunts
- •6.1.7.1 Discussion
- •6.1.8.1 Discussion
- •6.1.9.1 Discussion
- •6.1.10 Lumboperitoneal Shunts
- •6.1.10.1 Discussion
- •6.1.11 Third Ventriculocisternostomy
- •6.1.11.1 Discussion
- •6.1.12.1 Discussion
- •6.1.13 Aqueductoplasty
- •6.1.13.1 Discussion
- •6.1.14.1 Discussion
- •6.2.1.1 Discussion
- •6.2.2.1 Discussion
- •6.2.3 Intraventricular Fat Migration
- •6.2.3.1 Discussion
- •6.2.4.1 Discussion
- •6.2.5.1 Discussion
- •6.2.6 Slit Ventricle Syndrome
- •6.2.6.1 Discussion
- •6.2.7.1 Discussion
- •6.2.8 Shunt-Associated Infections
- •6.2.8.1 Discussion
- •6.2.9.1 Discussion
- •6.2.10.1 Discussion
- •6.2.11.1 Discussion
- •6.2.12 Peritoneal Pseudocysts
- •6.2.12.1 Discussion
- •6.2.13.1 Discussion
- •6.2.14 Tumor Seeding
- •6.2.14.1 Discussion
- •6.2.15 Shunt Catheter Calcification
- •6.2.15.1 Discussion
- •6.2.16.1 Discussion
- •6.2.17.1 Discussion
- •Further Reading
- •Types of Procedures
- •External Ventricular Drainage
- •Ventriculoperitoneal Shunts
- •Atypical Ventricular Shunts
- •Ventriculosubgaleal Shunts
- •Subdural-Peritoneal Shunts
- •Lumboperitoneal Shunt
- •Third Ventriculostomy
- •Aqueductoplasty
- •Fourth Ventricular Stenting
- •Complications
- •Intraventricular Fat Migration
- •Slit Ventricle Syndrome
- •Shunt-Associated Infections
- •Shunt Malposition and Migration
- •Pseudocysts
- •Cerebrospinal Fluid Leak Syndrome
- •Tumor Seeding
- •Shunt Catheter Calcifications
- •7.1.1 Discussion
- •7.2.1 Discussion
- •7.3.1 Discussion
- •7.4.1 Discussion
- •7.5.1 Discussion
- •7.6.1 Discussion
- •7.7 Radiosurgery for Vestibular Schwannomas
- •7.7.1 Discussion
- •Further Reading
- •Anterior Craniofacial Resection
- •Transsphenoidal Resection
- •Middle Cranial Fossa Reconstruction
- •Surgical Approaches for Vestibular Schwannoma Resection
- •8.1.1 Discussion
- •8.2 Auriculectomy
- •8.2.1 Discussion
- •8.3 Auricular Reconstruction
- •8.3.1 Discussion
- •8.4.1 Discussion
- •8.5 Atresiaplasty
- •8.5.1 Discussion
- •8.6.1 Discussion
- •8.7.1 Discussion
- •8.8 Ossicular Interposition
- •8.8.1 Discussion
- •8.9.1 Discussion
- •8.10.1 Discussion
- •8.11.1 Discussion
- •8.12 Atticotomy
- •8.12.1 Discussion
- •8.13.1 Discussion
- •8.14.1 Discussion
- •8.15.1 Discussion
- •8.16 Temporal Bone Resection
- •8.16.1 Discussion
- •8.17 Cochlear Implants
- •8.17.1 Discussion
- •8.18.1 Discussion
- •8.19.1 Discussion
- •8.20.1 Discussion
- •8.21.1 Discussion
- •8.22 Labyrinthectomy
- •8.22.1 Discussion
- •8.23 Vestibular Nerve Section
- •8.23.1 Discussion
- •8.24.1 Discussion
- •8.25.1 Discussion
- •Further Reading
- •BAHA Device
- •Auriculectomy
- •Auricular Reconstruction
- •Canaloplasty and Meatoplasty
- •Atresiaplasty
- •Myringoplasty and Tympanoplasty
- •Incus Interposition
- •Ossicular Prosthesis Complications
- •Transcanal Atticotomy
- •Mastoidectomy Complications
- •Lateral Temporal Bone Resection
- •Cochlear Implants
- •Cochlear Implant Complications
- •Auditory Brainstem Stimulator
- •Repair of Perilymphatic Fistula
- •Labyrinthectomy
- •Vestibular Nerve Sectioning
- •Tube Drainage of Cholesterol Cysts
- •9.1 Vertical Ramus Osteotomy
- •9.1.1 Discussion
- •9.2 Sagittal Split Osteotomy
- •9.2.1 Discussion
- •9.3 Genioplasty
- •9.3.1 Discussion
- •9.4.1 Discussion
- •9.5 Mandibular Distraction
- •9.5.1 Discussion
- •9.6 LeFort I Osteotomy
- •9.6.1 Discussion
- •9.7 LeFort III Osteotomy
- •9.7.1 Discussion
- •9.8.1 Discussion
- •9.9 Mandibulotomy
- •9.9.1 Discussion
- •9.10 Enucleation
- •9.10.1 Discussion
- •9.11 Cyst Decompression
- •9.11.1 Discussion
- •9.12 Coronoidectomy
- •9.12.1 Discussion
- •9.13.1 Discussion
- •9.14.1 Discussion
- •9.15.1 Discussion
- •9.16.1 Discussion
- •9.17.1 Discussion
- •9.18.1 Discussion
- •9.19.1 Discussion
- •9.20.1 Discussion
- •Further Reading
- •Vertical Ramus Osteotomy
- •Sagittal Split Osteotomy
- •Genioplasty
- •Mandibular Angle Augmentation
- •Mandibular Distraction
- •Lefort I Surgery
- •Lefort III Surgery
- •Fixation of Mandible Fractures
- •Mandibulotomy
- •Enucleation
- •Cyst Decompression
- •Coronoidectomy
- •Eminectomy and Meniscal Plication
- •10: Imaging the Postoperative Neck
- •10.1 Reconstruction Flaps
- •10.1.1 Discussion
- •10.2 Neck Dissection
- •10.2.1 Discussion
- •10.3 Parotidectomy
- •10.3.1 Discussion
- •10.4.1 Discussion
- •10.5 Facial Reanimation
- •10.5.1 Discussion
- •10.6.1 Discussion
- •10.7.1 Discussion
- •10.8 Transoral Robotic Surgery
- •10.8.1 Discussion
- •10.9 Sistrunk Procedure
- •10.9.1 Discussion
- •10.10 Laryngectomy
- •10.10.1 Discussion
- •10.11.1 Discussion
- •10.12 Montgomery T-Tubes
- •10.12.1 Discussion
- •10.13 Salivary Bypass Stent
- •10.13.1 Discussion
- •10.14 Laryngeal Stents
- •10.14.1 Discussion
- •10.15.1 Discussion
- •10.16 Arytenoid Adduction
- •10.16.1 Discussion
- •10.17 Arytenoidectomy
- •10.17.1 Discussion
- •10.18 Laryngeal Cartilage Remodeling
- •10.18.1 Discussion
- •10.19 Tracheotomy
- •10.19.1 Discussion
- •10.20 Thyroidectomy
- •10.20.1 Discussion
- •10.21.1 Discussion
- •10.22 Brachytherapy
- •10.22.1 Discussion
- •10.23 Vagal Nerve Stimulation
- •10.23.1 Discussion
- •Further Reading
- •Reconstruction Flaps
- •Facial Reanimation
- •Tonsillectomy and Adenoidectomy
- •Transoral Robotic Surgery
- •Neck Dissection
- •Parotidectomy
- •Salivary Duct Stenting
- •Laryngectomy
- •Montgomery T-Tubes
- •Salivary Bypass Stents
- •Laryngeal Stents
- •Arytenoid Adduction
- •Arytenoidectomy
- •Laryngeal Cartilage Remodeling
- •Tracheotomy
- •Thyroidectomy
- •Neck Exploration and Parathyroidectomy
- •Sistrunk Procedure
- •Brachytherapy
- •Vagal Nerve Stimulation
- •11: Imaging of Postoperative Spine
- •11.1 Overview
- •11.2 Spine Decompression
- •11.2.1.1 Discussion
- •11.2.2 Laminectomy
- •11.2.2.1 Discussion
- •11.2.3 Facetectomy
- •11.2.3.1 Discussion
- •11.2.4 Microdiscectomy
- •11.2.4.1 Discussion
- •11.2.5 Laminoplasty
- •11.2.5.1 Discussion
- •11.2.6 Vertebrectomy
- •11.2.6.1 Discussion
- •11.2.7 Cordectomy
- •11.2.7.1 Discussion
- •11.3.1 Halo and Traction Devices
- •11.3.1.1 Discussion
- •11.3.2 Bone Graft Materials
- •11.3.2.1 Discussion
- •11.3.3 Implantable Bone Stimulators
- •11.3.3.1 Discussion
- •11.3.4 Odontoid Screw Fixation
- •11.3.4.1 Discussion
- •11.3.5 Occipitocervical Fusion
- •11.3.5.1 Discussion
- •11.3.6 Anterior Cervical Fusion
- •11.3.6.1 Discussion
- •11.3.7.1 Discussion
- •11.3.8 Posterior Fusion
- •11.3.8.1 Discussion
- •11.3.9 Scoliosis Rods
- •11.3.9.1 Discussion
- •11.3.10 Vertebral Stapling
- •11.3.10.1 Discussion
- •11.3.11 Vertical Expandable Prosthetic Titanium Rib (VEPTR)
- •11.3.11.1 Discussion
- •11.3.12 Interbody Fusion
- •11.3.12.1 Discussion
- •11.4.1 Total Disc Replacement
- •11.4.1.1 Discussion
- •11.4.2.1 Discussion
- •11.4.3.1 Discussion
- •11.4.4 Dynamic Facet Replacement
- •11.4.4.1 Discussion
- •11.4.5 Dynamic Rods
- •11.4.5.1 Discussion
- •11.5.1 Overview
- •11.5.2.1 Discussion
- •11.5.3.1 Discussion
- •11.5.4.1 Discussion
- •11.5.5 Cerebrospinal Fluid Leak
- •11.5.5.1 Discussion
- •11.5.6.1 Discussion
- •11.5.7 Surgical Site Infections
- •11.5.7.1 Discussion
- •11.5.8 Postoperative Neuritis
- •11.5.8.1 Discussion
- •11.5.9 Arachnoiditis
- •11.5.9.1 Discussion
- •11.5.10.1 Discussion
- •11.5.11 Postoperative Synovial Cyst
- •11.5.11.1 Discussion
- •11.5.12 Residual/Recurrent Tumors
- •11.5.12.1 Discussion
- •11.5.13 Inclusion Cysts
- •11.5.13.1 Discussion
- •11.5.14.1 Discussion
- •11.5.15 Retained Surgical Tools
- •11.5.15.1 Discussion
- •11.5.16 Gossypiboma
- •11.5.16.1 Discussion
- •11.5.17.1 Discussion
- •11.5.18 Postoperative Deformity
- •11.5.18.1 Discussion
- •11.6.1 Discussion
- •11.7 Spinal Cord Stimulators
- •11.7.1 Discussion
- •11.8 Filum Terminale Sectioning
- •11.8.1 Discussion
- •11.9.1 Vertebral Augmentation
- •11.9.1.1 Discussion
- •11.9.2 Kiva Device
- •11.9.2.1 Discussion
- •11.9.3 Sacroplasty
- •11.9.3.1 Discussion
- •11.9.4.1 Discussion
- •11.9.5.1 Discussion
- •11.9.6.1 Discussion
- •Further Reading
- •Overview
- •Laminectomy
- •Facetectomy
- •Microdiscectomy
- •Laminoplasty
- •Vertebrectomy
- •Cordectomy
- •Bone Graft Materials
- •Implantable Bone Stimulators
- •Odontoid Screw Fixation
- •Anterior Cervical Fusion
- •Posterior Fusion
- •Occiptiocervical Fusion
- •Scoliosis Rods
- •Vertebral Stapling
- •Interbody Fusion
- •Nucleus Pulposus Replacement
- •Dynamic Facet Replacement
- •Dynamic Rods
- •Cerebrospinal Fluid Leak
- •Seromas and Hematomas
- •Postoperative Infection
- •Postoperative Neuritis
- •Arachnoiditis
- •Postoperative Synovial Cyst
- •Residual/Recurrent Tumors
- •Inclusion Cysts
- •Retained Surgical Tools
- •Gossypiboma
- •Postoperative Deformity
- •Intrathecal Spinal Infusion Pump
- •Spinal Cord Stimulators
- •Filum Terminale Sectioning
- •Kiva Device
- •Sacroplasty
- •Percutaneous Spine Fusion
- •CT-Guided Epidural Blood Patch
- •12.1 Vascular Surgery
- •12.1.1.1 Discussion
- •12.1.2.1 Discussion
- •12.1.3.1 Discussion
- •12.1.4.1 Discussion
- •12.1.6.1 Discussion
- •12.1.7 Carotid Endarterectomy
- •12.1.7.1 Discussion
- •12.1.8 Carotid Body Stimulation
- •12.1.8.1 Discussion
- •12.1.9 Adjustable Vascular Clamp
- •12.1.9.1 Discussion
- •12.1.10.1 Discussion
- •12.2 Endovascular Surgery
- •12.2.7 Endovascular Reconstructive Treatment for Acute Ischemic Stroke Using Intra-arterial Thrombolysis or Embolectomy
- •12.2.10 Endovascular Stent Reconstructive Treatment for Extracranial Cerebrovascular Occlusive Disease
- •12.2.11 Endovascular Reconstructive Treatment for Active Extracranial Hemorrhage or Pseudoaneurysm
- •Further Reading
- •Vascular Surgery
- •Aneurysm and Hemostatic Ligation Clips
- •Intracranial Aneurysm Muscle Wrap
- •Vascular Malformation Surgery
- •Carotid Endarterectomy
- •Carotid Body Stimulation
- •Adjustable Vascular Clamp
- •Reconstruction of the Great Vessels
- •Endovascular Surgery
- •General Imaging Considerations Following Endovascular Cerebrovascular Procedures
- •Endovascular Treatment for Aneurysms
- •Endovascular Stent Reconstructive Treatment for Extracranial Cerebrovascular Occlusive Disease
- •Endovascular Reconstructive Treatment for Active Extracranial Hemorrhage or Pseudoaneurysm
- •Endovascular Treatment for Intracranial Venous Stenosis and Occlusion
- •Index
7 Imaging of the Postoperative Skull Base and Cerebellopontine Angle |
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7.4\ Transsphenoidal Resection
Complications
7.4.1\ Discussion
Sellar hematomas are not uncommon after transsphenoidal resection. When large, these can cause mass effect upon surrounding structures and produce symptoms. Subacute hematomas in the sella can display high signal on T1and T2-weighted MRI sequences and should not be mistaken for fat graft or residual tumor (Fig. 7.26). Gradient echo (GRE) or susceptibility-weighted imaging (SWI) techniques can sometimes be useful for identifying blood products on MRI, although susceptibility effects from air in the adjacent sphenoid sinus can limit assessment.
Arterial injury during transsphenoidal resection is uncommon, but can manifest as pseudoaneurysm and/or subarachnoid hemorrhage, which can lead to vasospasm. Most arterial complications related to transsphenoidal surgery involve the internal carotid artery, but the ophthalmic, posterior communicating, and anterior cerebral arteries may also be affected. Arterial injury may occur during dural opening, tumor resection, or reconstruction of the sinuses and may be predisposed by anatomic variants of the sinuses and internal carotid arteries and large tumors that involve the cavernous sinus. Therefore, meticulous preoperative planning with imaging is important for minimizing arterial injury.
Once arterial injury is suspected during transsphenoidal resection, angiography is essential for identifying the presence of pseudoaneurysms. The speculum and packing material may be kept within the sphenoid sinus in order to prevent exsanguination, and excess packing may result in arterial stenosis or occlusion. Endovascular control of bleeding may be achieved by either balloon occlusion or coil embolization of the affected internal carotid artery, coil embolization of the pseudoaneurysm, or stenting alone of the affected segment of the internal carotid artery (Fig. 7.27). Peritumoral hemorrhage can lead to delayed cerebral vasospasm and associated progressive worsening neurological deficits.
Malposition or migration of packing material for transsphenoidal resection is uncommon. The displaced packing material can exert mass effect upon the optic chiasm, resulting in visual symptoms that may differ from the preoperative deficits (Fig. 7.28). Alternatively, the packing material can extend posteriorly and compress the brainstem (Fig. 7.29). Such complications can be readily demonstrated on multiplanar CT or MRI. However, in some cases, displacement of packing material can potentially mimic tumor invasion.
Mucosal inflammation is fairly common after transsphenoidal resection and most commonly involves the sphenoid sinuses (Fig. 7.30). On the other hand, mucocele formation after transsphenoidal resection is a rare or perhaps under-reported complication. Scar tissue can obstruct the egress of mucous secretions, resulting in their accumulation. On MRI, mucoceles are often homogeneously isoto hyperintense on T1and T2-weighted sequences and display peripheral enhancement. These may sometimes be multilocular. The main differential consideration is a postoperative hematoma, although these can be distinguished by their time course. Hematomas tend to resorb over time, while mucoceles persist or even expand. Susceptibilityweighted imaging can also be helpful, whereby hematomas are hypointense, while mucoceles do not. Postoperative mucoceles can cause symptoms, such as headache and diplopia, but they can be successfully treated via incision and drainage.
Although prophylactic antibiotics are routinely given before transsphenoidal surgery, the incidence of postoperative meningitis is in the range of 0.4–9%. This complication can manifest as leptomeningeal enhancement in the basilar cistern region on MRI (Fig. 7.31). The presence of postoperative cerebrospinal fluid leakage is an important risk factor for meningitis after transsphenoidal surgery.
Cerebrospinal fluid leak is a known complication of transsphenoidal resections. This is a serious complication that can predispose to meningitis and intracranial hypotension. The beta-2-transferrin assay is an accurate test for confirming the presence of cerebrospinal fluid leaks. Imaging also
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plays an important role in the workup of cerebrospinal fluid leak: it is used to confirm the diagnosis, localize the site of cerebrospinal fluid leak, identify a potential cause, and help plan surgical repair. Several imaging modalities are available to evaluate cerebrospinal fluid leak, including high-resolu- tion CT, CT cisternography, MRI, and radionuclide cisternography (Fig. 7.32). However, high-resolu- tion CT is the first-line imaging modality and can correctly predict the site of cerebrospinal fluid leak in over 90% of cases. When beta-2 transferrin is positive and high-resolution CT demonstrates a single bony defect without any sign of encephalocele, no other imaging is necessary. CT cisternography is reserved for patients with a negative high-resolution CT or multiple bony defects and active cerebrospinal fluid leakage. The sensitivity of CT cisternography is only about 50% in patients with intermittent cerebrospinal fluid leak. MR cisternography should be performed if high-resolu- tion CT shows a bony defect with an associated soft tissue opacity in order to exclude the possibility of meningocele or encephalocele. Contrast- enhanced sequences are useful for detecting dural enhancement at the site of the leak. Nuclear cisternography using In-111 is sometimes performed for complex cases and to help determine whether there is indeed a cerebrospinal fluid leak.
A variety of endocrinological disturbances can occur after transsphenoidal resection. In the acute postoperative setting, a minority of patients experience diabetes insipidus. This is associated with absence of the posterior pituitary bright spot on imaging. On the other hand, hyponatremia related to transsphenoidal surgery tends to have a delayed onset. Panhypopituitarism can result from transection of the hypophysis. This can best be evaluated using high-resolution MRI sequences, such as CISS and thin-section
T1-weighted images (Fig. 7.33). In addition, an ectopic posterior pituitary bright spot can be observed in this condition.
Ptosis of the optic chiasm is not an uncommon finding following pituitary tumor resection. This phenomenon tends to occur when a large portion of the pituitary sella contents have been evacuated resulting in a nearly or completely empty sella (Fig. 7.34). Ptosis is recognized by a convex- down configuration of the optic chiasm on a coronal or sagittal plane. When severe, this condition has the potential to cause visual deficits. The problematic empty sella with optic chiasm ptosis can be treated via chiasmopexy. This procedure consists of supporting the optic chiasm in near- anatomic position via transsphenoidal Silastic struts and coils, among other materials (Fig. 7.35). Acute visual loss related to transsphenoidal surgery can result from infarction of the optic apparatus if the blood supply is disrupted during tumor resection. This can be assessed on coronal T2-weighted MRI, which may show new signal abnormality in the optic apparatus (Fig. 7.36).
Fibrosis following transsphenoidal pituitary surgery is not an uncommon finding on postoperative MRI. Fibrosis can manifest as linear or amorphous areas within the sella. The imaging appearance is often indistinguishable from implant materials or residual tumor. Occasionally, adhesion bands form that extend across the sella or diaphragm to the brain or residual tumor. Adhesions appear as linear structures with low to intermediate signal intensity on T1-weighted and T2-weighted MRI sequences and enhance less and/or slower than the pituitary stalk (Fig. 7.37). These adhesions can hamper subsequent surgical resection of residual tumor. Fibrosis may also prevent normal pituitary gland re-expansion and cause stalk deviation.
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Fig. 7.26 Postoperative hematoma. Coronal T2-weighted (a), T1-weighted (b), and post-contrast T1-weighted (c) MR images show the intrinsically hyperintense fluid collection in the sella (arrows) after recent transsphenoidal surgery
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Fig. 7.27 Carotid artery injury. Preoperative coronal postcontrast T1-weighted MRI (a) shows a large pituitary adenoma that extends into the cavernous sinuses. Postoperative scout (b) and axial CT image (c) show transsphenoidal
speculum. Digital subtraction carotid angiograms show a right cavernous carotid pseudoaneurysm (arrow) adjacent to the speculum (d). The pseudoaneurysm was successfully treated via endovascular coiling (e)
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Fig. 7.28 Suprasellar fat graft compressing the optic chiasm. Within an hour of arrival in the recovery room after transsphenoidal pituitary resection, the patient was found to have new visual deficits, different from the preoperative symptoms. Sagittal CT image (a) and sagittal T1-weighted MRI (b) show the fat graft (arrows) extending into the suprasellar space. Pneumocephalus is also present
Fig. 7.29 Merocel migration and brainstem compression. Axial CT image (a) shows low-intensity sponge-like material posterior to the sella that compresses the brainstem (arrow). Similarly, the sagittal T2-weighted MRI (b) shows the spongy hypointense packing material extending posteriorly, exerting mild mass effect upon the brainstem (arrow)
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Fig. 7.30 Sinus inflammation. The patient presented with symptoms of congestion following transsphenoidal pituitary adenoma resection. Preoperative sagittal contrast-enhanced T1-weighted MRI (a) shows a pituitary
macroadenoma (*) but a clear sphenoid sinus. Postoperative sagittal post-contrast coronal T1-weighted MRI (b) demonstrates complete extensive mucosal thickening of the sphenoid sinus (arrow)
Fig. 7.31 Postoperative infection. Axial post-contrast fat-suppressed T1-weighted MRI shows diffuse leptomeningeal enhancement centered about the basal cisterns due to meningitis
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Fig. 7.32 Cerebrospinal fluid leak. The patient underwent transsphenoidal resection of a pituitary adenoma. Approximately 1 week after surgery, the patient presented with a cerebrospinal fluid leak. Oblique coronal CT (a) cisternogram image with the patient scanned in a prone position shows pooling of contrast around the fat graft that has partially herniated inferiorly into the sphenoid sinus through a bony defect in the floor of the sella with a
meningocele and spillage of contrast into the sphenoid sinus (arrow). The patient was scanned in a prone position in order to direct a maximum amount of contrast to the site of suspected cerebrospinal fluid leakage. Nuclear medicine cisternogram (b) also shows radiotracer activity localizing to the paranasal sinuses (arrow). Cerebrospinal fluid was also seen percolating around the fat graft during the subsequent surgery
Fig. 7.33 Pituitary stalk transection. The patient is status post-transsphenoidal decompression of sellar/suprasellar Rathke’s cleft cyst complicated by transection of the pituitary stalk and secondary panhypopituitarism. The thick- slab sagittal MIP T1-weighted MRI shows interruption of the infundibulum (arrow)
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Fig. 7.35 Chiasmopexy. Coronal CT image shows a strip of Silastic (arrow) in the sella, which was used to support a sagging optic chiasm
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Fig. 7.34 Optic chiasm ptosis. Preoperative coronal T2-weighted MRI (a) shows a large macrocystic pituitary adenoma that uplifts the optic chiasm (arrow). Postoperative coronal T2-weighted MRI (b) demonstrates ptosis of the optic chiasm (arrow) into an otherwise empty sella
Fig. 7.36 Optic nerve ischemia. The patient presented with new visual deficits after transsphenoidal surgery. Coronal T2-weighted MRI shows hyperintensity and swelling of the right optic chiasm (arrow)
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Fig. 7.37 Postoperative fibrosis. Axial T2-weighted (a) and post-contrast T1-weighted (b) MR images show an intermediate intensity band (arrows) traversing the sella anterior to the pituitary stalk