Abby Chainani, MD and Mohammad Bashir, MD
University of Iowa Hospital and Clinics, Iowa City, IA, USA
This chapter is a revision and update of that included in the previous edition of the TSRA Operative Dictations in
Cardiothoracic Surgery written by Franjo Siric, MD and A. Marc Gillinov, MD.
Essential Operative Steps
- Lines and Monitoring
- General endotracheal anesthesia
- Intraoperative TEE
- Median sternotomy
- Open pericardium, elevate the right side of the pericardium with stay sutures, and survey the ascending aorta for plaque
burden and cannulation site - Systemic heparinization (400 u/kg)
- Aortic cannulation
- Venous cannulation – bicaval
- Aortic root vent
- Check ACT (>480 seconds)
- Initiate CPB
- Maintain normothermia
- Aortic crossclamp
- Antegrade cold blood cardioplegia (1000-1200mL)
- Dissect Sondergaard’s groove, mobilize SVC and IVC for exposure
- Standard left atriotomy
- Expose the mitral valve; if further exposure is needed, open the left pleural space
- Excise a portion of anterior leaflet, preserving the subvalvular apparatus
- Size valve
- Place annular valve sutures (pledgets on the left atrial side)
- Implant the valve
- Left atriotomy closure
- Deairing maneuvers
- Remove aortic crossclamp
- Check for hemostasis
- Place epicardial atrial and ventricular pacing wires
- Wean from cardiopulmonary bypass
- Evaluate mitral valve with transesophageal echocardiogram
- Venous decannulation
- Ensure adequate deairing of the heart prior to removal of aortic root vent
- Protamine administration for heparin reversal
- Aortic decannulation
- Assess hemostasis
- Sternotomy closure
Potential Complications and Pitfalls
- Stay midline during the sternotomy
- Avoid injury to the innominate vein while making pericardial well
- Cannulation catastrophe (aortic dissection/hematoma, right atrial tear)
- Poor choice of location of aortic cannula/crossclamp (risk of stroke)
- Injury of the pulmonary artery during crossclamp application
- Insufficient myocardial protection and cardiac arrest (crossclamp not across, aortic regurgitation with secondary
ventricular distension) - Feel the left ventricle during administration of antegrade cardioplegia to ensure absence of ventricular distension and
uniform cooling of the ventricle with cardioplegia - Poor venous drainage (incorrect choice of cannula size, advancing the two-stage cannula too far in so it is obstructing
the hepatic veins) - Poor exposure due to lack of mobilization of both cavae
- Failure to dissect Sondergaard’s groove
- Improper dissection of Sondergaard’s groove with inadvertent opening of the right atrium close to the inferior vena cava
- Opening the left atrium close to the right superior pulmonary vein with subsequent difficulty in exposing the mitral
valve - Retractor injury with subsequent shearing tear of the left atrial wall edges which complicates closure
- Failure to recognize important vital structures in relation to the mitral valve: the atrioventricular node, coronary sinus,
aortic valve, and circumflex coronary artery - Improper placement of the annular sutures with misidentification of the mitral annulus and subsequent placement of the
sutures in the left atrial wall - Deep placement of annular sutures with subsequent injury to the circumflex coronary artery in a left dominant system
- LVOT obstruction by the valve strut
- Improper deairing prior to removal of the aortic root vent
- Lifting the heart with the prosthesis in place causing atrioventricular groove disruption: it is important to avoid lifting
the heart after mitral valve replacement due to risk of atrioventricular disruption. If there is calcium in the subannular
space, debried only if necessary as ventricular calcium debridement also increases risk of atrioventricular groove
disassociation. In the event of atrioventricular groove disruption, rearrest the heart, remove the prosthesis to inspect
ventricle, place a pericardial patch over the disrupted area, and replace the mitral valve with posterior leaflet tissue
acting to buttress the patch repair. Placing deep annular sutures can injure the aortic cusps, conduction system, and
circumflex artery which can require redo mitral valve replacement, aortic valve replacement, pacemaker placement, and
reverse saphenous vein graft to the circumflex artery - Inadequate control of hemostasis prior to sternal closure/bleeding from cannulation sites
- Improper closure of sternotomy
Template Dictation
Preoperative Diagnosis: Severe mitral valve regurgitation/stenosis
Postoperative Diagnosis: Same (with appropriate adjustments)
Indications for procedure: For mitral stenosis, MVR is indicated for moderate (mean valve area ≦1.5cm²) to severe mitral
stenosis if the patient has significant symptoms, NYHA class III/IV heart failure not amenable to percutaneous options.
Additionally, MVR is indicated for patients with mild symptoms (NYHA class II), severe MS, and pulmonary hypertension
(PAP >50mmHg at rest, >60mmHg with exercise). For mitral regurgitation, MVR is indicated for symptomatic acute severe
MR, chronic severe MR with NYHA class II/III/IV symptoms, and asymptomatic severe MR with LV dysfunction.
Procedure(s) Performed: Mitral valve replacement
Attending Surgeon: [BLANK]
Secondary Surgeon: [BLANK]
Assistants: [BLANK]
Anesthesia: [BLANK]
Indication(s) for Procedure: [AGE] year old [SEX] with [DURATION] history of [COMPLAINT: e.g. increasing
shortness of breath]. Preoperative transthoracic echocardiography reveals [FINDINGS: e.g. severe mitral valve regurgitation
and stenosis due to advanced rheumatic disease].
Description of the Procedure: After satisfactory general endotracheal anesthesia was induced, a right internal jugular central
venous line, pulmonary artery catheter, and brachial arterial line were inserted. Transesophageal echocardiogram was
performed to evaluate the mitral valve and cardiac function. The patient was prepped and draped in the supine position.
A standard median sternotomy was performed, and a sternal retractor was placed. We opened the pericardium in an inverted
T-shape fashion and pericardial stay sutures were placed on the right side. Heparin was given systemically, and an aortic
cannula was inserted through two pursestring sutures in the distal ascending aorta, secured, and deaired. Bicaval cannulation
proceeded. An aortic root cardioplegia cannula/vent was then inserted. After confirming ACT >480 seconds, cardiopulmonary
bypass was commenced at 2.4L/min/m2. We maintained normothermia during perfusion. The aorta was crossclamped. After
administering 750mL of Buckberg cardioplegia antegrade, we administered 500mL of cardioplegia in the retrograde fashion.
Thereafter, cold blood cardioplegia was given retrograde every 15-20 minutes. Simultaneously, we developed Sondergaard’s
groove between the left and right atrium and opened the left atrium about 1-2cm away from the orifice of the right upper
pulmonary vein to decompress it. A self-retracting Cosgrove retractor was applied to the sternal retractor. Once cardioplegia
was given, the self-retracting arms of the Cosgrove retractor were placed starting cranially to visualize the mitral valve. Once
we confirmed that the valve could not be repaired, we incised the anterior leaflet in its mid-portion. Before we cut it all out,
we started placing everting, interrupted 2-0 ethibond pledgeted stitches on the anterior annulus gently lifting the anterior leaflet
to facilitate visualization. We made our way to both commissures, detached the remainder of the anterior mitral leaflet, divided
it in the middle, and brought the segments to the left and right to preserve chordae. Preserved portions of the anterior leaflet
were sewn to the annulus towards the left and right commissures, away from central portion of the inflow, with double armed
interrupted 2-0 ethibond pledgeted mattress stitches. An appropriately sized [VALVE TYPE AND SIZE] valve was selected,
and sutures were placed through the sewing cuff orienting the struts in a way to avoid obstructing the left ventricular outflow
tract. Atrial closure was completed after deairing. Retrograde and antegrade “Hot Shots” were given and the aortic crossclamp
was released. Following thorough deairing, we removed the aortic vent. The IVC cannula was removed while still on partial
bypass, the cannulation site was reinforced, and CPB was weaned off. Ventricular and atrial pacing wires were placed. Every
attempt was made not to lift the heart with the bioprosthesis in place given the possibility of posterior LV wall rupture. A test
dose of protamine was administered, and the patient was monitored for adverse reaction before the protamine was resumed.
The aortic cannula was then removed. Adequate hemostasis was then confirmed within the mediastinum. The sternum was
then closed with a total of [NUMBER] stainless steel sternal wires. The wound was irrigated with antibiotic solution. The
fascia was then closed with #1 vicryl suture in a running fashion. The deep dermal layer was closed with 2-0 vicryl suture in a
running fashion. The skin and subcuticular layer were closed with 3-0 monocryl in a running fashion. The skin of the wound
was cleansed with sterile saline and dressed with antibiotic ointment and a Primapore dressing.
All instrument, sponge, and needle counts were confirmed to be correct, twice, at the end of the operation. The patient was
subsequently transferred to the postoperative cardiac surgical intensive care unit in critical condition.
Dr. [BLANK] was present and scrubbed for [BLANK] elements of the procedure.
Multiple Choice Question(s)
Which of the following does NOT describe a strategy to prevent AV groove disruption during mitral valve replacement?
A. Avoid lifting the heart after prosthesis is placed.
B. Attempt to preserve posterior leaflet
C. Avoid debridement of calcium in the sub-annular space.
D. Place pledgets on the atrial side if the annulus is calcified
E. Avoid deep sutures in the posterior annulus
Answer: E. Atrioventricular disruption after mitral valve replacement generally results from technical error. This can be due
to excessive traction on the annulus during valve excision, extensive debridement of calcified annulus with perforation more
likely to occur on the ventricular side, disruption of the atrioventricular groove from lifting the heart after the prosthesis is
placed, and deep sutures in the posterior annular space that can penetrate the atrioventricular groove. Preserve the posterior
leaflet when possible. When the annulus is calcified, it is recommended to place pledgets on the ventricular side rather than
atrial side to prevent atrioventricular groove disruption. Therefore, E is the correct answer.
Sources
Yuh, David Daiho, Luca A. Vricella, Stephen Yang, and John R. Doty. Johns Hopkins textbook of cardiothoracic surgery.
McGraw Hill Professional, 2014.
Kaiser, Larry, Irving L. Kron, and Thomas L. Spray, eds. Mastery of cardiothoracic surgery. Lippincott Williams & Wilkins,
2013.
Members, Writing Committee, et al. “2020 ACC/AHA guideline for the management of patients with valvular heart disease:
a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice
Guidelines.” Journal of the American College of Cardiology 77.4 (2021): e25-e197.
