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Official Description

Thymectomy, partial or total; sternal split or transthoracic approach, without radical mediastinal dissection (separate procedure)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

A thymectomy, which can be either partial or total, is a surgical procedure that involves the removal of the thymus gland, an organ located in the upper chest beneath the sternum. This gland plays a crucial role in the immune system, particularly during fetal development and childhood, as it is responsible for the production and maturation of T-lymphocytes, a type of white blood cell essential for immune response. The thymus reaches its peak size during puberty and subsequently diminishes, being replaced by fatty tissue in adulthood. The procedure is typically performed using either a sternal split or a transthoracic approach and is indicated for various conditions, including non-metastatic thymoma, thymic carcinoid, thymic carcinoma, and myasthenia gravis. The surgical approach allows for direct access to the thymus, facilitating its removal while minimizing damage to surrounding structures. It is important to note that this procedure is classified as a separate procedure and does not involve radical mediastinal dissection, which is a more extensive surgical intervention that may be required in cases where metastatic lesions are present.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The thymectomy procedure is indicated for the following conditions:

  • Non-metastatic thymoma - A tumor originating from the thymus gland that has not spread to other parts of the body.
  • Thymic carcinoid - A rare type of tumor that arises from neuroendocrine cells in the thymus.
  • Thymic carcinoma - A malignant tumor of the thymus that is more aggressive than thymoma.
  • Myasthenia gravis - An autoimmune disorder characterized by weakness and rapid fatigue of voluntary muscles, which may be associated with thymic abnormalities.

2. Procedure

The thymectomy procedure involves several detailed steps to ensure the safe and effective removal of the thymus gland:

  • Step 1: The surgical team begins by making an incision over the sternum, which allows for access to the chest cavity. If a sternal split approach is chosen, the incision is extended to expose the manubrium, which is then completely divided.
  • Step 2: The sternal split is carried down to the third or fourth intercostal space, allowing the sternum to be retracted. This retraction provides access to both pleural spaces, where the phrenic nerves are identified to avoid injury during the procedure.
  • Step 3: The overlying mediastinal pleura is carefully divided to expose the anterior thymus and the innominate vein. This step is crucial for visualizing the thymus and surrounding structures.
  • Step 4: The thymus, along with the fat overlying the pericardium, is mobilized starting from the right inferior horn. This mobilization is performed meticulously to ensure that the thymus is freed from surrounding tissues.
  • Step 5: Once the lower horn is completely free, the right superior horn is mobilized. The thyrothymic ligament is then exposed and divided from the thyroid gland, followed by ligation of the ligament.
  • Step 6: The thymus is retracted toward the left side, and the lateral arterial blood supply from the internal mammary artery is isolated, ligated, and divided to prevent excessive bleeding.
  • Step 7: The left lower and upper horns of the thymus are freed in a similar manner as the right side, ensuring complete mobilization of the gland.
  • Step 8: After all four horns are mobilized, the innominate vein is clamped, divided, and suture ligated to facilitate the removal of the thymus.
  • Step 9: If a thymic mass is present, frozen sections are taken and sent to pathology for evaluation. This step is critical for determining the nature of the mass and guiding further treatment.
  • Step 10: Adjacent anatomical structures are inspected for possible metastatic lesions. If any lesions are identified, they are removed along with the thymus to ensure complete excision of any malignant tissue.
  • Step 11: A chest tube is placed to allow for drainage of any fluid that may accumulate postoperatively. The sternum is then closed using wire sutures, and the soft tissue and skin are closed with absorbable stitches to promote healing.

3. Post-Procedure

Post-procedure care following a thymectomy includes monitoring for complications such as bleeding, infection, or respiratory issues. Patients may require a chest tube for drainage, which is typically removed once fluid accumulation is resolved. Recovery time can vary, but patients are generally advised to avoid strenuous activities for a period to allow for proper healing. Follow-up appointments are essential to assess recovery and to monitor for any potential recurrence of thymic-related conditions.

Short Descr REMOVAL OF THYMUS GLAND
Medium Descr THYMECTOMY PRTL/TOT W/O RAD MEDSTNL DSJ SPX
Long Descr Thymectomy, partial or total; sternal split or transthoracic approach, without radical mediastinal dissection (separate procedure)
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 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) 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) P1G - Major procedure - Other
MUE 1
CCS Clinical Classification 12 - Other therapeutic endocrine procedures
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).
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
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.
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.
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).
CR Catastrophe/disaster related
GC This service has been performed in part by a resident under the direction of a teaching physician
RT Right side (used to identify procedures performed on the right side of the body)
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
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
Action
Notes
1995-01-01 Added First appearance in code book in 1995.
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