Summary & Overview

CPT 33412: Aortic Valve Replacement with Annular Enlargement or Konno Procedure

CPT code 33412 denotes surgical aortic valve replacement with annular enlargement or the Konno repair, procedures used to treat aortic stenosis or regurgitation and congenital left ventricular outflow tract obstruction. This code captures complex open-heart surgery that often requires cardiopulmonary bypass, intensive postoperative monitoring, and extended inpatient care — making it a high-resource cardiac surgical code with national relevance for surgical capacity, hospital resource planning, and payer coverage policies.

Key payers referenced in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical and billing overview, typical sites of service, and the clinical scenarios that justify use of the code. The publication summarizes common modifiers and administrative considerations, and it provides context for coding accuracy, documentation expectations, and code relationships for surgical valve replacement workflows.

This summary is intended for clinicians, coding professionals, and policy analysts seeking a national-level briefing on the clinical intent and administrative implications of CPT code 33412, including what to expect in terms of service intensity and inpatient resource use. Data not available in the input will be noted where applicable in detailed sections.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 33412aortic valve replacementcardiac surgeryKonno procedurevalve annulus enlargementinpatient surgerycardiothoracic surgery

Billing Code Overview

CPT code 33412 describes surgical replacement of the aortic valve with an artificial prosthesis, including enlargement of the aortic annulus when needed to accommodate a larger prosthetic valve. The code also covers the Konno procedure, a combined repair and aortic valve replacement used to treat congenital aortic stenosis at the left ventricular outflow tract.

Service type: Open cardiac surgical valve replacement with annular enlargement or Konno repair
Typical site of service: Inpatient hospital, operating room, with postoperative intensive care and monitored inpatient recovery

Clinical & Coding Specifications

Clinical Context

A typical patient is a 62-year-old male with progressive exertional dyspnea, angina, and syncope found to have severe aortic stenosis on echocardiography with mean gradient >40 mmHg and an aortic valve area <1.0 cm2. Coronary angiography shows no prohibitive coronary disease. After multidisciplinary heart team review, the patient is scheduled for surgical aortic valve replacement (SAVR) with annular enlargement (Konno or other aortic root enlargement technique) to permit insertion of a larger prosthetic valve and reduce patient–prosthesis mismatch. The clinical workflow includes preoperative evaluation (history and physical, transthoracic echo, transesophageal echo as indicated, cardiac catheterization, labs, and anesthesia assessment), intraoperative general endotracheal anesthesia with median sternotomy, cardiopulmonary bypass, aortic valve excision, annular enlargement and placement of a mechanical or bioprosthetic valve, and postoperative care in the cardiac surgical ICU with hemodynamic monitoring, anticoagulation management if mechanical valve implanted, and planned discharge once stable. Typical site of service is an inpatient acute care hospital operating room with postoperative stay in an intensive care unit.

Coding Specifications

For the procedure described by 33412, the most clinically relevant modifier codes are listed below.

Modifier	Description	When to Use
`62`	Two surgeons	Used when two surgeons work together as primary surgeons performing distinct operative tasks during the SAVR with annular enlargement.
`80`	Assistant surgeon	Used when a surgical assistant performs a portion of the procedure and payer requires reporting of assistant-at-surgery services.
`81`	Minimum assistant surgeon	Used when a physician provides minimal assistance rather than full assistant-at-surgery duties.
`82`	Assistant surgeon (when qualified resident not available)	Used if a qualified resident is not available and an assistant surgeon is required.
`22`	Increased procedural services	Applied when procedure complexity or time significantly exceeds typical and additional documentation supports unusual effort.
`52`	Reduced services	Applied when the procedure is partially reduced or not completed as originally intended.
`53`	Discontinued procedure	Used when the operation is started but discontinued for patient safety before completion.
`76`	Repeat procedure by same physician	Used when the same physician repeats the procedure later during the same encounter (note: `76` may not be on the provided list; if absent use `77` or others per payer).
`78`	Unplanned return to the operating room for a related procedure during the postoperative period	Used when patient returns to OR for a complication related to the initial SAVR.
`79`	Unrelated procedure or service by the same physician during the postoperative period	Used when an unrelated procedure is performed during global period (not in provided list).
`AS`	Medically directed/attending doctor for special payment rules (Ambulance or Anesthesia)	Applied per payer-specific guidance when reporting anesthesia/team arrangements; included because anesthesia modifiers may apply to the case.
`ET`	End-stage renal disease related monthly service (rarely used here)	Included in provided list but rarely applicable; not typically used for SAVR unless ESRD monthly services reported.
`QK`	Medical direction of two, three, or four concurrent anesthesia procedures involving qualified individuals	Used if physician directs multiple concurrent anesthesia services during the case.
`QX`	CRNA service with medical direction	Used when a CRNA provides anesthesia under medical direction and payer requires the modifier.

Taxonomy Code	Specialty	Notes
`2080S00000X`	Cardiothoracic Surgery	Primary specialty performing `33412` in most centers.
`207RC0000X`	Cardiovascular Disease (Cardiology)	Participates in diagnostics, preop evaluation, and heart team decisions.
`207L00000X`	Anesthesiology	Provides intraoperative anesthesia care and qualifies for anesthesia-related modifiers.
`163W00000X`	Perfusionist (not a physician taxonomy)	Essential intraoperative role though not billed under physician CPT; listed here for care team context.
`261QP0800X`	Critical Care Medicine	Manages postoperative ICU care and contributes to postoperative decision-making.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I35.0`	Nonrheumatic aortic (valve) stenosis	Primary indication for aortic valve replacement with annular enlargement to treat severe stenosis.
`I35.1`	Nonrheumatic aortic (valve) insufficiency	Aortic regurgitation that may necessitate valve replacement when severe.
`I35.2`	Nonrheumatic aortic (valve) stenosis with insufficiency	Mixed disease where replacement is often indicated.
`Q23.2`	Congenital aortic stenosis	Pediatric or congenital cases where Konno procedure may be indicated to enlarge annulus and replace valve.
`I39`	Endocarditis and heart valve disorders in diseases classified elsewhere	Infective involvement of the aortic valve may require surgical replacement.
`I50.9`	Heart failure, unspecified	Resultant symptomatic heart failure may be an indication for valve intervention.
`Z95.2`	Presence of prosthetic heart valve	Postoperative status code used in longitudinal records after valve replacement.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`33405`	Replacement, aortic valve, with cardiopulmonary bypass; with tissue graft (bioprosthesis)	Alternative code when a surgical aortic valve replacement is performed without annular enlargement; may be used if no enlargement performed.
`33430`	Replacement, aortic valve, with cardiopulmonary bypass; with cardiopulmonary bypass, mechanical valve	Used when a mechanical prosthesis is implanted during SAVR; commonly documented alongside `33412` if annular enlargement also performed (report per coding rules).
`33967`	Implantation of intracardiac mechanical circulatory support device (ventricular assist device), non-biventricular	Occasionally performed in complex cases where ventricular support is required in addition to valve surgery.
`93505`	Catheterization of a coronary artery with diagnostic injection; single major coronary artery	Used in the preoperative workup for coronary anatomic assessment before valve surgery.
`93306`	Echocardiography, transthoracic, real-time with image documentation, complete	Preoperative and postoperative transthoracic echocardiography to assess valve function and ventricular performance.
`92920`	Cardiopulmonary resuscitation (external cardiac massage)	Emergency code sometimes reported if intraoperative or postoperative cardiac arrest occurs during the surgical episode.