Off-pump Coronary Artery Bypass Surgery in a Patient with Dextrocardia and Situs Inversus: Anesthetic, Surgical Consideration and Role of Transesophageal Echocardiography.

Coronary artery bypass surgery (CABG) in dextrocardia with situs inversus patients is reported less in literature. Due to abnormal looping and associated other congenital anomalies, anesthetic implications and surgical difficulties become challenging in these patients. Transesophageal echocardiography examination (TEE) needs multiplane angle adjustments compared to normal heart to obtain the images. Here, we describe a 53-year-old female patient having dextrocardia with situs inversus who underwent CABG and discuss the perioperative management and multiplane adjustments during TEE examination.

INTRODUCTION

Dextrocardia with situs inversus is a rare congenital abnormality with an incidence of 1:10,000.[1] It involves a left-handed malrotation of the visceral organs. The incidence of coronary artery disease in these patients is similar to that of the general population.[2]

Coronary artery bypass surgery (CABG) operations in dextrocardia patients are a challenging task to the operating surgeon due to the position of the heart. Here, we discuss the anesthetic management, surgical difficulties, and various multiplane angle adjustments required during transesophageal echocardiography (TEE) examination.

CASE PRESENTATION

A 53-year-old obese female patient presented with the right-sided chest pain and dyspnea on exertion for 2 years. Her vital signs on admission were HR: 88/min, BP: 130/90 mmHg, RR: 14/min and Spo2 100%. She was a known case of diabetes mellitus, hypertension, hypothyroidisim, and bronchial asthma on regular treatment.

Seven years back, she had undergone stenting to left anterior descending (LAD) coronary artery.

Electrocardiogram (ECG) showed inverted P wave along with negative QRS complex in lead I, positive QRS deflection in lead aVR, and poor progression of R wave in chest leads. Chest X-ray showed dextrocardia and abdominal ultrasound examination confirmed the presence of situs inversus. Coronary angiogram showed ostial morphologic LAD occlusion (in-stent restenosis) and 90% discrete lesion in morphologic left circumflex with right dominance. Transthoracic echocardiography showed dextrocardia with ejection fraction of 45%, with regional wall motion abnormalities in LAD territory. Her biochemical and hematological investigations were with normal limits. She was referred for coronary artery bypass grafting surgery.

Induction was done as per the standard protocol for CABG patients, 7.5F central line was introduced in the left internal jugular vein and ECG leads were placed in the right side in view of dextrocardia. TEE probe was introduced without any difficulty. Intraoperative TEE images were recorded.

In contrary to the TEE images in situs, in midesophageal (ME) four chamber view, the right atrium and right ventricle (RV) were seen in the left side of the image sector at 0° [Figure 1 and Video 1]. In ME two chamber view, the structures were similar to the normal heart [Figure 2 and Video 2]. ME long-axis view (LAX) was obtained at an angle of 40°, in contrary to an angle of 120° in normal heart [Figure 3 and Video 3]. ME modified bicaval view was obtained at an angle of 60°, in contrary to an angle of 110°–120° in normal heart [Figure 4 and Video 4]. ME aortic valve short-axis view (SAX) was obtained at angle of 120° in contrary to an angle of 30° in normal heart [Figure 5 and Video 5]. Coronary sinus was seen after slight retroflexion of the probe from ME four chamber view, in the left side of the image sector at 0° in contrary to the right side of the image sector in normal heart [Figure 6 and Video 6]. ME ascending aorta SAX was obtained at 0° with pulmonary artery on the left of the image sector and superior vena cava on the right side [Figure 7 and Video 7]. ME ascending aorta LAX view was similar to normal heart at 90° [Figure 8 and Video 8]. In transgastric (TG) basal and mid-papillary SAX view, left ventricle was seen on the right side of the image sector [Figure 9 and Video 9]. TG two chamber view was similar to normal heart [Figure 10 and Video 10]. TG right ventricular inflow-outflow view was obtained at 55° in contrary to 110°–120° in normal heart [Figure 11 and Video 11]. ME descending thoracic aorta view was similar to normal heart [Figure 12 and Video 12].

Figure 1

Midesophageal four chamber view

Figure 2

Midesophageal two chamber view

Figure 3

Midesophageal left ventricle long-axis view

Figure 4

Midesophageal modified bicaval view

Figure 5

Midesophageal aortic valve short-axis view

Figure 6

Midesophageal coronary sinus view

Figure 7

Midesophageal ascending aorta short-axis view

Figure 8

Esophageal ascending aorta long-axis view

Figure 9

Transgastric mid short-axis view

Figure 10

Transgastric two chamber view

Figure 11

Transgastric right ventricle inflow-outflow view

Figure 12

Midesophageal descending thoracic aorta short-axis view

After median sternotomy, right internal mammary artery (RIMA) was harvested. RIMA was anastomosed to morphological LAD and saphenous venous graft was anastomosed to the marginal branch. The operating surgeon was on the left side of the patient while operating. After surgery, the patient was shifted to postoperative intensive care unit, extubated after 4 h of mechanical ventilation, and discharged without any complication.

DISCUSSION

Dextrocardia is a rare cardiac anomaly in which the heart is located in the right hemithorax and its base to apex axis is directed toward the right side. In situs inversus, the chest and abdominal organs are arranged in mirror image reversal of the normal position.

The anatomist surgeon, Hieronymus Fabricius, first described dextrocardia in 1606.[3] Marco Aurelio Severinus first described dextrocardia with situs inversus in 1643.[4] The first CABG was done in a patient with dextrocardia in 1980.[5]

Embryologically, dextrocardia with situs inversus is due to 270° clockwise rotation of the developing thoracoabdominal organs instead of the normal 270° counterclockwise rotation.[6] Dextrocardia can be associated with other cardiac anomalies with isolated dextrocardia but rare in situs inversus totalis with dextrocardia.

Anesthetic consideration in dextrocardia includes proper preoperative evaluation, placement of ECG electrodes in the opposite side, introduction of central venous catheter in the left side internal jugular vein because of its straight course to the anatomical left atrium.

In dextrocardia, the presence of RV on the left side and anterior to the left ventricle also coursing of LAD on the right side of the heart makes revascularization of LAD with left internal mammary artery (LIMA) difficult because of the short course of LIMA. Usually, RIMA is anastomosed to LAD, considering its proximity to rightward LAD.[7]

Most surgeons prefer to stand on the left side of the patient while anastomosing in dextrocardia patients due to the position of the heart. However, there are reports showing surgeons operating in the conventional position as well.[8] In case of on-pump CABG, location of aortic arch should be considered before aortic cannulation as in dextrocardia, aortic arch may be right sided.[9] The presence of bilateral superior vena cava has to be checked before venous cannulation.[10]

TEE examination in dextrocardia patients needs probe and multiplane plane angle manipulations due to abnormal looping. TEE views such as ME four chamber view, ME aortic SAX axis view, and TG basal/mid SAX view appear as mirror image of the normal heart. TEE images obtained at 120° in ME aortic LAX view are obtained at 30°–40° in dextrocardia patients. However, TEE views obtained at an angle of 90° in dextrocardia patients are similar to normal heart.

CONCLUSION

CABG in dextrocardia patients is challenging and can be performed successfully. Careful perioperative evaluation, intraoperative positioning of heart, selection of conduits and graft configuration, multiplane angle and probe adjustments in TEE are needed due to abnormal looping of heart in dextrocardia.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.