Surgical Positions in CP Angle tumors.pptx

Surgical approaches to expose the tumor which is required

1. Patient Positioning In CP Angle Tumors Presenter: Dr Charan Kollanur Moderator: Prof R N Sahu

2. Cerebellopontine (CP) angle tumors, V estibular schwannomas, M eningiomas, and Epidermoid Proper positioning : M inimizes complications, E nsures effective retraction, and A ccess to critical neurovascular structures. INTRODUCTION precise positioning for optimal surgical exposure and patient safety

3. Maximize surgical exposure + M inimizing brain retraction. Maintain hemodynamic stability and prevent complications like venous congestion. Protect the airway and reduce the risk of pressure ulcers or nerve injuries. Facilitate cerebrospinal fluid (CSF) drainage for brain relaxation. Objectives of Proper Positioning

4. Retrosigmoid approach Posterior petrosectomies Retrolabyrinthine presigmoid approach Trans labarynthine approach Trans cochlear approach. Anterior petrosectomies Middle fossa approach (KAWASEs Approach) Surgical Approaches for CP angle tumors

5. Middle fossa approach Retrosigmoid approach Translabrynthine approach

6. 🔹  Used for:  Vestibular schwannomas, meningiomas, epidermoid tumors. 🔹  Position:   Supine lateral/ Semi lateral Lateral or Park-bench 🔹  Goal:  Maximize exposure while minimizing cerebellar retraction. A. Retrosigmoid approach

7. Head Positioning Gently rotated toward the floor Slightly flexed toward the chest  to expose posterior fossa Laterally flexed towards floor - mastoid tip at the upper edge of the surgical field  To better exposure of sub occipital area

8. 🔹  Used for:  Small tumors confined to the internal auditory canal (IAC). 🔹  Position:   Supine with Head Turned to the Opposite Side 🔹  Goal:  Access the temporal bone and IAC while preserving hearing. B. Middle Fossa Approach

9. 🔹  Used for:  Large CP angle tumors where hearing preservation is not a priority. 🔹  Position:   Supine with Head Turned Laterally 🔹  Goal:  Direct access to the mastoid and petrous bone for complete tumor removal. C. Translabyrinthine / Transcochlear Approach

10. Patient lies on the side , with the affected side up. Head slightly flexed forward (chin-to-chest)  to open the posterior fossa. Mayfield head clamp or gel pads  secure the head. Shoulder opposite to the lesion is slightly pulled down  using a soft strap. Dependent arm (lower arm) is placed forward on a padded arm board. Upper arm is supported  to avoid brachial plexus stretch injuries. Legs are flexed slightly , with a pillow between the knees for comfort. Table is slightly tilted head-up (Reverse Trendelenburg)  to facilitate venous drainage. Lateral Positioning

11. Good CPA exposure M inimizing cerebellar retraction Provides gravity-assisted CSF drainage Minimizes cranial nerve traction. Advantages ❌ Cardio vascular  Risk of reduced venous return ❌ Respiratory  Ventilation-perfusion mismatch in dependent lung ❌  Risk of arm and shoulder nerve compression (brachial plexus, ulnar nerve) . ❌  Venous congestion  if excessive neck rotation is applied. ❌ P ostoperative visual loss (POVL)  Increase in IOP (head tilt downwards >30 0) ❌ A cute postoperative sialadenitis   Complications

12. Park Bench Position Patient lies on their side , with the head  flexed and rotated slightly downward . Torso is slightly tilted forward  over the table edge. Arms are padded and positioned carefully : The lower arm rests on a padded arm board / sling. The upper arm is placed on an armrest or supported with pillows/padding. Lower leg is flexed; upper leg is extended slightly , with padding between them. Head is fixed with a Mayfield clamp  or S ugita . Venous drainage is optimized  by slightly tilting the table.

13. Maximises CPA exposure  wide manipulation of neck. M inimizing cerebellar retraction Provides gravity-assisted CSF drainage Minimizes cranial nerve traction. Advantages ❌ Cardio vascular  Risk of reduced venous return ❌ Respiratory Ventilation-perfusion mismatch in dependent lung ❌  Risk of arm and shoulder nerve compression (brachial plexus, ulnar nerve) . (less when compared lateral decubitus) ❌  Venous congestion  if excessive neck rotation is applied.   Complications

14. Supine lateral/ Semi lateral Position Patient lies supine (on their back). A Bolster kept below the ipsilateral shoulder for oblique positioning Head is rotated 60–90° toward the opposite side (Transpetrossal approaches) 30-40 Middle fossa approaches Mayfield clamp or Sugita frame is used for stabilization. Neck is kept neutral to prevent jugular vein compression. A slight head tilt (15–30° elevation) is applied to improve venous return. Arms are placed comfortably with padding, and pressure points are protected.

15. Greater patient stability Improved surgical ergonomics : Surgeons comfort minimizing fatigue. Lower risk of complications Provides gravity-assisted CSF drainage M inimizing cerebellar retraction Minimizes cranial nerve traction. Advantages ❌  Neck strain  due to excessive rotation. ❌  Jugular vein compression  increasing intracranial pressure. ❌  Potential airway compromise  if excessive head turn occurs.   Complications

16. Semi sitting Position

17. Improved ventilation –less pulmonary complications Clear surgical field drainage of blood Early decompression of cisterna magna Reduced cerebellar engorgement: minimize venous congestion in the cerebellum facilitates careful dissection of the facial nerve, minimizes cranial nerve traction. Advantages ❌  Risk of venous air embolism (VAE) ❌  Patient selection: Midline tumor involvement Large tumor size Pre OP good neurologic status   Complications Contraindications: Poor cardiovascular status

18. Lateral Semi-sitting Position

19. Clear surgical field gravity drainage of blood Minimise cerebellar retraction Reduced cerebellar engorgement: minimize venous congestion in the cerebellum facilitates careful dissection of the facial nerve, minimizes cranial nerve traction. Advantages ❌  Risk of venous air embolism (VAE)   ❌ Neck strain  due to excessive rotation. ❌  Jugular vein compression  increasing intracranial pressure. ❌  Potential airway compromise  if excessive head turn occurs.   Complications Patient selection: Large tumor size Lateral tumor location No contra indication for semi sitting position

20. ✅  Neurophysiological Monitoring Ensure access for facial nerve monitoring, brainstem auditory evoked potentials (BAEPs), and motor evoked potentials (MEPs). Avoid excessive head rotation, which may interfere with nerve conduction studies. ✅  Venous Air Embolism (VAE) Risk Management Highest in  semi-sitting position . Precordial Doppler monitoring and  aspiration of central venous lines  help detect VAE early. Keep intravenous fluids running to  maintain adequate venous pressure . SPECIAL CONSIDERATIONS IN POSITIONING

21. ✅  CSF Drainage Strategy A  lumbar drain  may be placed preoperatively to improve brain relaxation. ✅  Eye Protection Adequate eye padding  prevents corneal abrasions and optic nerve compression. In  lateral and park-bench positions , tape the eyelids closed to avoid drying. ✅  Pressure Point Protection Elbows, heels, knees, and sacrum  should be padded to prevent pressure ulcers. Ulnar nerve and brachial plexus  injuries can be prevented with proper arm support.

22. Thank You