CARDIOVASCULAR ANESTHESIA: Case Report
The use of transesophageal echocardiography (TEE) is rapidly becoming an accepted technique for intraoperative cardiovascular monitoring. TEE examinations are performed with an ultrasound transducer mounted at the tip of a modified gastroscope; hence, the risk of this procedure can be compared with routine gastroscopy. The safety aspects of conventional endoscopic procedures have been well documented. However, when compared with routine endoscopy, TEE studies require increased diligence because of the lack of optical control during probe insertion and manipulation in the esophagus.
The following is a case of an unsuccessfully placed TEE probe. The patient was a 68-yr-old man who presented for coronary artery bypass surgery. Cardiac catheterization showed severe three-vessel coronary artery disease (left main coronary artery 26%–50%, left anterior descending coronary artery 76%–90%, left circumflex coronary artery 90%–99%, right coronary artery 100%) and an estimated ejection fraction of 23%. The patient denied any chest pain or dyspnea on exertion. Additional comorbid conditions included hypertension, chronic obstructive pulmonary disease, peripheral vascular disease, peptic ulcer disease, and gastroesophageal reflux disease. A social history revealed a 60-pack/yr smoking history and moderate alcohol consumption.
The patient weighed 64 kg, and was 168 cm in height. After recommended American Society of Anesthesiologists monitoring was established, arterial and pulmonary artery catheters were inserted before the induction of the anesthetic state by midazolam and fentanyl. Rocuronium was used to facilitate tracheal intubation, and ventilation was confirmed by the presence of a normal end-tidal CO2 waveform.
After the orogastric tube was passed and removed without difficulty for gastric decompression, a 5-MHz adult Omniplane TEE probe (Hewlett-Packard, Waltham, MA) was atraumatically inserted through the oropharynx into the proximal esophagus by the attending anesthesiologist. At a depth of 30 cm from the incisors, resistance to advancement was encountered. Attempts to rotate the transducer probe while applying gentle pressure did not facilitate its passage. At this point, we decided that immediate gastroscopy was indicated for both diagnostic purposes and further management guidance.
A pediatric video gastroscope was passed with ease under direct visualization through the hypopharynx into the esophagus. There was a stricture with ulcerated mucosa noted in the esophagus approximately 30 cm from the incisors. The residual lumen measured approximately 10 mm in diameter (Fig. 1). Although mucosa surrounding the stricture was smooth, there was 1-cm linear ulcer adjacent to the stricture and evidence of distal linear erosion. No discrete lesion or mass effect was visualized; however, brushings were obtained for cytology. At this point, we decided to postpone surgery because of concern for increased esophageal bleeding after heparinization and to allow time to eliminate esophageal malignancy (Fig. 2).
TEE is considered a low-risk procedure. The reported mortality rate associated with TEE is 0.01%–0.03% (1 in 3827 and 1 in 10,218 examinations), but in most cases a causal link with TEE probe placement has not been established (1). In comparison, diagnostic upper gastrointestinal endoscopy has an overall complication rate in the range of 0.1% and a mortality rate <0.005%(2). Although data regarding TEE-induced esophageal injuries are limited, perforation along the orogastric pathway during fiberoptic gastroscopy occurs with a rate of 1 in 3020 (0.03%) to 1 in 12,644 (0.008%) (2). Forty percent of those perforations occur in the hypopharynx, whereas only 20% occur in the esophagus. Several reasons are indicated for this predilection, including a tenuous blood supply and a thin pharyngeal wall with a lack of protective mucosa. However, the incidence of clinically obvious perforation may underestimate the true frequency of esophageal injury.
TEE examinations require greater attention to detail to avoid an increased risk of complications. TEE examinations are often performed in patients with more extensive comorbid conditions, and TEE examinations occur without direct visualization during probe insertion and manipulation.
Some resistance is often encountered when passing the probe through the hypopharynx as well as during probe advancement from the esophagus to the stomach, usually for patients with hiatal hernia. Alternatively, resistance to probe advancement in the midesophageal portion (generally beginning at 20–25 cm from the incisors and extending down to 35–40 cm) is uncommon unless there is pathology involved. Therefore, the possibility of esophageal stricture, tumor, interruption, or recent esophageal injury should be suspected when problems with probe passage occur at this level. Relative contraindications for probe insertion include esophageal varices, Zenker’s diverticulum, Barrett’s esophagus, and previous radiation therapy of the esophageal area (3).
1. Daniel WG, Erbel R, Kasper W, et al. Safety of transesophageal echocardiography: a multicenter survey of 10,419 examinations. Circulation 1991; 83: 817–21.
2. Pasricha PJ, Fleischer DE, Kalloo AN. Endoscopic perforation of the upper digestive tract: a review of their pathogenesis, prevention, and management. Gastroenterology 1994; 106: 787–802.
© 2001 International Anesthesia Research Society
3. American Society of Anesthesiologists, Society of Cardiovascular Anesthesiologists. Practice guidelines for perioperative transesophageal echocardiography: a report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Anesthesiology 1996; 84: 986–1006.