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Official Description

Infratemporal pre-auricular approach to middle cranial fossa (parapharyngeal space, infratemporal and midline skull base, nasopharynx), with or without disarticulation of the mandible, including parotidectomy, craniotomy, decompression and/or mobilization of the facial nerve and/or petrous carotid artery

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Common Language Description

The CPT® Code 61590 refers to a surgical procedure that utilizes an infratemporal pre-auricular approach to access the middle cranial fossa. This approach is particularly beneficial for exposing extradural or intradural lesions located in the parapharyngeal space, infratemporal region, midline skull base, and nasopharynx. The procedure begins with an incision that starts near the midline at the top of the skull, extending laterally over the temporal region, and then descending in front of the ear along the pre-auricular crease, reaching down to the level of the tragus. This incision is further extended into the neck to facilitate access to the internal carotid artery, allowing for better control during the procedure. The surgical technique involves elevating a scalp flap and the temporalis muscle from the temporal fossa, followed by dissection of the fascia of the masseter muscle to expose the parotid gland, which may be removed during a parotidectomy. For enhanced visibility and access, the mandible may be disarticulated from its attachments to the temporal bone. A temporal craniotomy is then performed, with the specific placement of osteotomies guided by the lesion's location. Once the cranium is opened, protective measures are taken for the orbital soft tissues, and the frontal lobe is retracted to allow for further dissection. The procedure includes identifying and decompressing or mobilizing critical neurovascular structures such as the facial nerve and the petrous carotid artery. After ensuring the preservation of these structures, the dissection of the lesion commences, which is documented separately. This comprehensive approach allows for effective management of complex lesions within the specified anatomical regions.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

The procedure described by CPT® Code 61590 is indicated for various conditions that necessitate access to the middle cranial fossa and surrounding anatomical structures. The following are the explicitly provided indications for performing this surgical intervention:

  • Extradural or intradural lesions that require surgical exposure and intervention.
  • Lesions located in the parapharyngeal space that may affect surrounding neurovascular structures.
  • Pathologies involving the infratemporal and midline skull base that necessitate direct access for treatment.
  • Conditions affecting the nasopharynx that require surgical intervention for diagnosis or treatment.

2. Procedure

The procedure involves several critical steps to ensure effective access and management of the targeted lesions. Each step is detailed as follows:

  • Step 1: Incision - The surgical process begins with an incision that is strategically placed near the midline at the top of the skull. This incision extends laterally over the temporal region and descends in front of the ear along the pre-auricular crease, reaching down to the level of the tragus. This careful placement is essential for optimal access to the underlying structures.
  • Step 2: Neck Access - The incision is further extended into the neck to provide necessary access and control over the internal carotid artery, which is crucial for the subsequent steps of the procedure.
  • Step 3: Scalp Flap Elevation - A scalp flap is elevated to expose the underlying tissues, allowing for further dissection and access to the temporal region.
  • Step 4: Temporalis Muscle Elevation - The temporalis muscle is carefully elevated off the temporal fossa to facilitate access to deeper structures and ensure that the surgical field is clear.
  • Step 5: Parotidectomy - The fascia of the masseter muscle is dissected to expose the parotid gland, which may be removed as part of the parotidectomy, depending on the nature of the lesion and the surgical plan.
  • Step 6: Mandibular Disarticulation - For wider exposure, the mandible may be disarticulated from its attachments to the temporal bone, allowing for enhanced access to the surgical site.
  • Step 7: Temporal Craniotomy - A temporal craniotomy is performed, with the precise placement of osteotomies determined by the location of the lesion. This step is critical for accessing the cranial cavity.
  • Step 8: Protection of Orbital Soft Tissues - Once the cranium is opened, protective measures are taken to safeguard the orbital soft tissues, ensuring they are not compromised during the procedure.
  • Step 9: Frontal Lobe Retraction - The frontal lobe is retracted to provide a clear view of the infratemporal skull base, facilitating further dissection.
  • Step 10: Identification of Neurovascular Structures - Soft tissues are dissected off the infratemporal skull base, allowing for the identification and potential decompression or mobilization of the facial nerve and the petrous carotid artery as needed.
  • Step 11: Lesion Dissection - After all critical neurovascular structures are identified and preserved, the dissection of the lesion begins, which is reported separately to ensure accurate documentation and coding.

3. Post-Procedure

Post-procedure care following the surgical intervention described by CPT® Code 61590 involves monitoring for any complications related to the surgery, such as bleeding, infection, or neurological deficits. Patients may require pain management and close observation in a recovery setting. The expected recovery period will vary based on the extent of the surgery and the individual patient's health status. Follow-up appointments are essential to assess healing, manage any postoperative symptoms, and evaluate the success of the intervention. Additional imaging studies may be necessary to ensure that the lesion has been adequately addressed and to monitor for any recurrence.

Short Descr INFRATEMPORAL APPROACH/SKULL
Medium Descr INFRATEMPORAL MID CRANIAL FOSSA W/WO DISARTICLTN
Long Descr Infratemporal pre-auricular approach to middle cranial fossa (parapharyngeal space, infratemporal and midline skull base, nasopharynx), with or without disarticulation of the mandible, including parotidectomy, craniotomy, decompression and/or mobilization of the facial nerve and/or petrous carotid artery
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) 1 - 150% payment adjustment for bilateral procedures applies.
Physician Supervisions 09 - 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) 2 - Team surgeons permitted; pay by report.
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) P1G - Major procedure - Other
MUE 1
CCS Clinical Classification 1 - Incision and excision of CNS

This is a primary code that can be used with these additional add-on codes.

69990 Addon Code MPFS Status: Restricted APC N ASC N1 PUB 100 CPT Assistant Article 1Microsurgical techniques, requiring use of operating microscope (List separately in addition to code for primary procedure)
RT Right side (used to identify procedures performed on the right side of the body)
22 Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service.
50 Bilateral procedure: unless otherwise identified in the listings, bilateral procedures that are performed at the same session, should be identified by adding modifier 50 to the appropriate 5 digit code. note: this modifier should not be appended to designated "add-on" codes (see appendix d).
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
62 Two surgeons: when 2 surgeons work together as primary surgeons performing distinct part(s) of a procedure, each surgeon should report his/her distinct operative work by adding modifier 62 to the procedure code and any associated add-on code(s) for that procedure as long as both surgeons continue to work together as primary surgeons. each surgeon should report the co-surgery once using the same procedure code. if additional procedure(s) (including add-on procedure(s) are performed during the same surgical session, separate code(s) may also be reported with modifier 62 added. note: if a co-surgeon acts as an assistant in the performance of additional procedure(s), other than those reported with the modifier 62, during the same surgical session, those services may be reported using separate procedure code(s) with modifier 80 or modifier 82 added, as appropriate.
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
78 Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.)
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
80 Assistant surgeon: surgical assistant services may be identified by adding modifier 80 to the usual procedure number(s).
82 Assistant surgeon (when qualified resident surgeon not available): the unavailability of a qualified resident surgeon is a prerequisite for use of modifier 82 appended to the usual procedure code number(s).
AG Primary physician
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
CR Catastrophe/disaster related
GC This service has been performed in part by a resident under the direction of a teaching physician
LT Left side (used to identify procedures performed on the left side of the body)
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
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Notes
1994-01-01 Added First appearance in code book in 1994.
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