CPT® Code 61542

Official Description

Craniotomy with elevation of bone flap; for total hemispherectomy

Common Language Description

The procedure described by CPT® Code 61542 involves a craniotomy with elevation of the bone flap for a total hemispherectomy. In simpler terms, this surgical intervention is performed on the brain, which is divided into two halves known as the right and left cerebral hemispheres. Each hemisphere consists of an outer layer of grey matter, referred to as the cerebral cortex, and an inner layer of white matter. These two hemispheres are connected by a structure called the corpus callosum. A hemispherectomy is a surgical procedure that entails the total or partial removal of one of the cerebral hemispheres, and in the case of code 61542, a complete removal, known as an anatomic hemispherectomy, is performed. During an anatomic hemispherectomy, the surgeon removes the entire affected hemisphere, which includes the frontal, parietal, temporal, and occipital lobes, while leaving deeper brain structures such as the basal ganglia, thalamus, and brain stem intact. The surgical process begins with a long incision in the scalp, which is made starting from the front of the skull and extending across the midline to the opposite side. A scalp flap is then created to provide access to the skull. Burr holes are drilled into the skull, and the bone between these holes is cut and elevated to create a bone flap. The dura mater, a protective membrane covering the brain, is opened in a specific manner, allowing the surgeon to access the brain tissue. Using a surgical microscope, the surgeon carefully dissects the tissue along the interhemispheric fissure, which is the space between the two hemispheres. The callosal fibers, which connect the two hemispheres, are divided using suction aspiration and bipolar coagulation techniques. The dissection continues until the affected hemisphere is fully mobilized, at which point it is excised. This complex procedure is typically indicated for patients with severe neurological conditions that affect one hemisphere of the brain, necessitating its removal to alleviate symptoms or improve quality of life.

1. Indications

The procedure described by CPT® Code 61542 is indicated for specific neurological conditions that necessitate the removal of an entire cerebral hemisphere. These conditions may include:

Severe Epilepsy - Patients with intractable epilepsy that does not respond to medication may require a total hemispherectomy to control seizures.
Brain Tumors - Malignant or aggressive tumors located in one hemisphere may necessitate complete removal to prevent further spread and to alleviate symptoms.
Traumatic Brain Injury - Severe injuries affecting one hemisphere may lead to the need for surgical intervention to remove damaged brain tissue.
Hemispherectomy for Hemiplegia - In cases where one hemisphere is severely affected, leading to significant motor deficits, a total hemispherectomy may be performed to improve function and quality of life.

2. Procedure

The procedure for CPT® Code 61542 involves several critical steps that ensure the safe and effective removal of the affected hemisphere. The steps are as follows:

Step 1: Incision and Scalp Flap Creation - A long skin incision is made starting anterior to the coronal suture on the left side of the skull and is carried across the midline to the right side. This incision allows for the creation of a scalp flap, which is lifted to expose the underlying skull.
Step 2: Drilling Burr Holes - Burr holes are drilled slightly to the left of the midline to facilitate access to the skull. These holes are strategically placed to allow for the cutting of the bone between them.
Step 3: Elevation of Bone Flap - The bone between the burr holes is cut using a saw or craniotome, and the bone flap is elevated to provide access to the brain beneath.
Step 4: Opening the Dura Mater - The dura mater is opened in a curvilinear fashion, beginning at the sagittal sinus and is then retracted to expose the brain tissue.
Step 5: Dissection of the Interhemispheric Fissure - Using a surgical microscope, the surgeon dissects down the interhemispheric fissure, carefully separating the two hemispheres.
Step 6: Division of Callosal Fibers - The callosal fibers connecting the two hemispheres are divided using suction aspiration and bipolar coagulation techniques, starting through the genu and anterior callosum.
Step 7: Identification and Division of the Midline Raphe - The midline raphe, which separates the lateral ventricles, is identified, and a ball dissector is used to divide the perpendicular fibers in the posterior aspect of the corpus callosum.
Step 8: Mobilization and Excising the Affected Hemisphere - The dissection continues until the affected hemisphere is completely mobilized, at which point it is excised from the brain.
Step 9: Closure of the Dura and Bone Flap - After the excision, the dura is closed, and the bone flap is replaced and secured using sutures, wires, or miniplate and screws.
Step 10: Repair of Overlying Tissue - The overlying muscle is repaired, and the galea and skin are closed in layers to complete the procedure.

3. Post-Procedure

Post-procedure care following a total hemispherectomy involves monitoring the patient for any complications, such as infection or bleeding. Patients may require intensive care initially to manage pain and monitor neurological status. Rehabilitation services, including physical, occupational, and speech therapy, are often necessary to assist the patient in adjusting to the changes following the removal of a hemisphere. The expected recovery period can vary significantly based on the individual patient's condition and the extent of the surgery, but ongoing follow-up care is essential to support recovery and address any long-term effects of the procedure.

Short Descr	REMOVAL OF BRAIN TISSUE
Medium Descr	CRANIOTOMY TOTAL HEMISPHERECTOMY
Long Descr	Craniotomy with elevation of bone flap; for total hemispherectomy
Status Code	Active Code
Global Days	090 - Major Surgery
PC/TC Indicator (26, TC)	0 - Physician Service Code
Multiple Procedures (51)	2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50)	0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions	9 - Concept does not apply.
Assistant Surgeon (80, 82)	2 - Payment restriction for assistants at surgery does not apply to this procedure...
Co-Surgeons (62)	1 - Co-surgeons could be paid, though supporting documentation is required...
Team Surgery (66)	0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family	99 - Concept Does Not Apply
APC Status Indicator	Inpatient Procedures, not paid under OPPS
Type of Service (TOS)	2 - Surgery
Berenson-Eggers TOS (BETOS)	none
MUE	Not applicable/unspecified.
CCS Clinical Classification	1 - Incision and excision of CNS