ACRT Journal

Keywords: Severe Aortic Stenosis (SAS); Plunging Thyroid Goiter; High-Risk Surgical Patients; Multidisciplinary Team; Preoperative Planning; Difficult Airway Management; Surgical Timing and Technique.

Introduction

Surgical intervention and the management of two complicated disease processes, especially in high-risk surgical patients, are now high on the list of health care providers’ agenda due to an aging society. First of all, degenerative aortic stenosis is a common condition in the elderly, it should be considered that is the most prevalent valvular heart disease in the elderly. It affects approximately 12% of people over the age of 75, with a higher prevalence in women than in men. [1] In particular, severe aortic stenosis (SAS) has one of the worst prognoses among valvular heart diseases. Furthermore, studies have shown that individuals with degenerative aortic stenosis often have comorbidities such as hypertension, diabetes, and coronary artery disease, which increases the complexity of managing this condition in older patients. [2] Although surgical and transcatheter aortic valve implantation (TAVI) improve the prognosis of severe aortic stenosis, SAS with left ventricular dysfunction represents a ‘difficult scenario’ for precise and definitive treatment. [3] Secondly, massive goiter with a cranial-caudal measurement of more than 8 cm or a substantially high cervical extension, so-called ‘plunging goiter’, occurs in less than 10% of cases and may invade structures within the thorax [4]. Anesthesia for thyroid surgery offers unique challenges, and advanced airway settings are often mandatory because of the difficulty of managing airway patency. [5] Severe aortic stenosis and a plunging goiter would be better managed from a comprehensive management point of view. To the best of our knowledge, none of the comprehensive international significant reports included a patient with the combined clinical condition as presented in this study, we have been the first group to describe a patient in whom severe aortic stenosis was surgically managed together with a plunging goiter, apart from a few cases that describe combined surgery of severe aortic stenosis and thyroidectomy [6,7]. Although the prevalence of these two diseases might not be so high, especially in developing countries, this comprehensive review is very useful for improving the management of such patients, optimizing the surgical outcome. Finally, an earlier onset of management with a modern procedure for aortic stenosis seems to be extremely important in receiving the best results. [8] The coordinated workflows and pathways ensure timely patient admissions and access to the specific class of treatments for certain diseases, such as myocardial infarction, acute stroke, heart failure, or sepsis. In the context of high-risk patients that have associated periprocedural complications, some protocols and algorithms have been instituted such as TAVI, a Percutaneous Transseptal Transcatheter Mitral Valve Procedure, mini-invasive surgical mitral valve intervention, and Ebstein’s surgery. [9] This article presents a complex medical situation of a septuagenarian patient, with the description of her medical history, preoperative diagnostics, chosen operative technique with results, and follow-up, who was admitted to the cardiosurgical department with the diagnosis of SAS and large plunging thyroid goiter. The case presents a typical clinical case highlighting the complex relationship between two distinct surgical areas: intracardiac and extracardiac. The extremely severe condition of the hospitalized patient (NYHA III), and the high risk of death during surgical treatment were the reasons for treatment to be carried out according to guidelines for a multidisciplinary approach. The purpose of the present comprehensive review is to provide insights concerning the existing evidence on the concomitance of severe aortic stenosis and plunging thyroid goiter regarding surgical patients, discuss admittance, evaluation of comorbid conditions, the current clinical practice, including a brief summary of pathophysiological mechanisms and reported management strategies, and finally, it analyzes the criteria for the assessment, the patient safety point of view the prevention of serious complications found using periprocedural anesthesia and surgical literature in patients who are unsuitable for the use of standard operative techniques. The important issue is ambiguity about standards during multidisciplinary approaches in this fragile population. [8,9] While cases of SAS in elderly and high-risk patients are still to be found in clinical practice, and much evidence exists on this topic, to the best of our knowledge, a comprehensive review about severe aortic stenosis with a coexistent plunging thyroid goiter in high-risk surgical populations does not exist. The primary objective of the combination of the above two diseases is to present the interdependence between the plunging thyroid goiter and the aortic valve directly connected with the aortic root and aorta. It may also shed some light on the necessity of combined treatment of patients with aortic stenosis and lesions located in the close neighborhood of the aortic root or other vascular structures. This subject is relevant to physicians and anesthesiologists who do not necessarily manage these diseases but are expected to possess knowledge of this issue. The present review summarizes previously published data and is designed to be an easy reference guide for use by a busy practicing clinician and therefore briefly describes the current clinical practice.

The aim of the presented paper is to determine the present management strategies and recent views on the prognosis in polymorbid patients with a coexisting plunging thyroid goiter. [6]

Case Presentation

We report the case of a 70-year-old female patient with a history of poorly controlled arterial hypertension, presenting with two coexisting conditions that required either a two-step approach or simultaneous management, involving a thyroidectomy followed by cardiac surgery under cardiopulmonary bypass (CPB). In our case, a simultaneous approach was chosen following a multidisciplinary consultation. With a medical history of poorly controlled arterial hypertension, a multinodular plunging goiter in hyperthyroidism treated with carbimazole 10 mg/day, and atrial fibrillation associated to severe aortic valve stenosis managed with acenocoumarin 4 mg (¼ tablet/day) and bisoprolol 2.5 mg/day, the patient presented with a progressively worsening condition. The onset of her symptom’s dates back to five months prior, marked by a brief episode of syncope, prompting an emergency consultation. Initial evaluation revealed tachycardia due to atrial fibrillation on a background of severe aortic valve stenosis. She was placed on symptomatic treatment. The course of her illness was characterized by a worsening baseline dyspnea, progressing from NYHA class II to class III, accompanied by exertional palpitations without chest pain. The patient was referred to the ENT consultation for progressively worsening dyspnea, associated with orthopnea and a massive goiter, and cardiology consultation for the evaluation of her heart disease. During her recent assessment she also reported reduced exercise tolerance and occasional dizziness with neck symptoms, including subclavicular pain and swallowing limitations. Clinical examination revealed a large goiter deforming the neck, visible on inspection, with signs of tracheal compression. Cardiac auscultation identified an intense systolic ejection murmur at the aortic focus radiating to the carotids, with no signs of right-sided heart failure or peripheral edema. Thyroid ultrasound showed a multinodular goiter containing hypoechoic cystic areas and calcifications, with a plunging thoracic component compressing cervical and superior mediastinal structures. A cervical-thoracic CT scan, with and without contrast injection, confirmed the plunging nature of the goiter. It extended into the anterior mediastinum, displacing the trachea and major vessels without evidence of invasion. The scan revealed a multinodular goiter characterized by generalized thyroid gland enlargement, predominantly affecting the left lobe, with an irregular, lobulated contour. The goiter is characterized by heterogeneity, macrocalcifications, and uneven enhancement, marking hypodense necrotic and/or cystic fluid-filled areas. The large goiter measures 12.13 x 9.06 x 6.63 cm in the left lobe, 10.5 x 6 x 5.36 cm in the right lobe, and 5 cm in the isthmus. It extends upwards to the submandibular spaces and laterally towards the anterior and posterior spinal spaces, particularly on the left side. The jugulo-carotid vascular axes are displaced laterally and posteriorly, but remain unobstructed. The goiter extends downward into the superior level of the anterior mediastinum, filling the prevascular space and pushing vascular structures posteriorly. It reaches the level of the superior border of the aortic arch, coming into contact with the supra-aortic trunks, exerting a mass effect, but without invasion or obstruction. The upper aerodigestive pathways are unobstructed and symmetrical, although there is posterior and rightward displacement at the larynx and trachea level, without narrowing or impact on their lumen, which remains patent and of normal size. (Figure 1) Transthoracic echocardiography revealed severe degenerative aortic stenosis with high pulmonary arterial hypertension for age (PASP through tricuspid regurgitation at 55 mmHg). The left ventricle was non-dilated, hypertrophied with an indexed mass of 107.11 g/m² (eccentric remodeling), end-diastolic diameter (EDD) at 44 mm, end-systolic diameter (ESD) at 28 mm, and preserved systolic function with an ejection fraction (EF) of 55% (biplane Simpson method). (Figure 2)

Figure 1: Axial CT scan with contrast injection showing overall hypertrophy of the thyroid gland, predominantly involving the left lobe, with irregular and nodular contours. The gland exhibits spontaneously heterogeneous density with heterogeneous enhancement (A, B). The upper aerodigestive tract remains unobstructed, with posterior and rightward displacement of the larynx and trachea, whose lumen remains patent and of normal caliber. (A, B) It extends to the superior mediastinum through the thoracic inlet, in a retrosternal position, filling the prevascular space up to the level of the superior border of the aorta and the supra-aortic trunk, which remain patent and uninvolved. (C)

Figure 2: Real-time echocardiographic image showing a non-dilated, hypertrophied left ventricle with an interventricular septum measuring 0.9 cm in diastole and 1.2 cm in systole. The indexed left ventricular mass was 107.11 g/m², indicating eccentric remodeling. The left ventricular end-diastolic diameter (EDD) measured 44 mm, the end-systolic diameter (ESD) measured 28 mm, and systolic function was preserved with an ejection fraction (EF) of 66% (Teichholz method). The shortening fraction was within the normal range at 36%.

Left ventricular filling pressures were normal, and the inferior vena cava was dilated to 16 mm and slightly compliant. (Figure 3,4) The left atrium was dilated, with a surface area of 21.5 cm² and a volume of 44 ml/m². (Figure 5) The right ventricle had preserved systolic function with a TAPSE (Tricuspid Annular Plane Systolic Excursion) of 22 mm and a tissue Doppler S’ velocity of 12 cm/s. The right atrium was dilated at 19.7 cm², free of echoes. Assessment of the valvular apparatus showed a tricuspid aortic valve with degenerative changes, including calcified masses between the right and left cusps, limiting valve opening. Severe stenosis was noted, with a valvular area of 0.8 cm² (indexed area of 0.58 cm²), a Vmax of 3.93 m/s, and a mean gradient of 35 mmHg. The aortic annulus measured 19 mm, and minimal regurgitation was observed. (Figure 6-9)

Figure 3: Doppler echocardiographic image of the transmitral antegrade flow showing a non-elevated mitral E-wave velocity of 1.36 m/s (<1.5 m/s), with the absence of an A-wave due to atrial fibrillation.

Figure 4: Tissue Doppler imaging (TDI) at the mitral annulus was performed using a 4-chamber view, minimizing filters and gains, and placing the sampling window at the lateral annulus (A) or the septal annulus (B). The TDI recording showed a positive systolic wave followed by a single diastolic Ea wave at 7 cm/s lateral, (A) and 11 cm/s septal, (B), with no Aa wave due to atrial fibrillation. The absence of significant reduction in the Ea wave indicates normal flow, as in healthy individuals, the Ea wave is typically greater than 8 cm/s

Figure 5: Zoomed echocardiographic image in the apical 4-chamber view focusing on the atria, showing a dilated left atrium with a surface area of 23.6 cm² (Figure A, blue arrow) and a volume of 58 ml/m² (Figure B, orange arrow). The right atrium is also dilated, measuring 19.7 cm², and appears free of echoes (Figure A, red arrow).

Figure 6: Parasternal short-axis echographic image showing a valvular area of 0.9 cm² by planimetry (indexed area of 0.7 cm²/m²).

Figure 7: Doppler echocardiographic image in the 5-chamber view at the level of the aortic valve, showing a mean transvalvular gradient of 35 mmHg.

Figure 8: 2D echocardiographic image in the parasternal long-axis view showing a non-dilated proximal aorta. The aortic annulus measures 2.7 cm, the sinus of Valsalva 2.5 cm, and the tubular segment 3.1 cm.

Figure 9: 2D echocardiographic image in the parasternal short-axis view, with pulsed Doppler pointed a few millimeters below the pulmonary valve (in the right ventricle), showing a pulmonary acceleration time to reach the peak velocity with an intermediate value of 126 ms, which is neither short (<90 ms) nor long (>130 ms).

The laboratory workup revealed an NT-proBNP level of 900 pg/ml, with no renal insufficiency, normal thyroid function and inflammatory markers. The preoperative coronary angiography showed atheromatous coronary arteries without significant lesions. The echodoppler of the supra-aortic trunks showed atheromatous changes without significant lesions. The rest of the biological, serological, and radiological assessments were normal. The therapeutic decision was based on combined expertise in both pathologies. Since symptomatic severe aortic stenosis was suspected to be the primary cause of the patient’s dyspnea, reduced walking distance, and markedly decreased quality of life, an isolated aortic valve intervention might have been considered. However, the left lobe of the retrosternal thyroid goiter plunged significantly into the left thoracic cavity, reaching the level of the superior border of the aortic arch and coming into contact with the supra-aortic trunks, exerting a mass effect. This made it impossible to exclude involvement due to this intrathoracic localization. Considering the rapidly appearance of Ortner’s syndrome and the almost hemodynamically significant stenosis, the presented symptomatic manifestations and predominantly affected valvular components led to an interdisciplinary evaluation. This evaluation concluded that the overall cardiopulmonary prognosis was severely compromised. A multidisciplinary meeting was organized, bringing together teams from endocrinology, ENT surgery, cardiology, cardiac surgery, and cardiovascular anesthesia and intensive care. It was decided to perform both surgical interventions in a single procedure rather than in two stages. A total thyroidectomy was performed to eliminate any risk of postoperative tracheal compression and to facilitate access to mediastinal structures, followed immediately during the same operative period by aortic valve replacement under Extracorporeal Circulation (ECC). The first stage consists of performing a total thyroidectomy which was performed by a specialized cervical surgery team. Nasotracheal intubation using a fibroscopic technique in a conscious patient was carried out, after performing bilateral superior laryngeal nerve blocks, a tracheal block via the cricothyroid membrane, and topical anesthesia through oral nebulization of 2% lidocaine and topical application of 5% lidocaine-naphazoline. (Figure 10) The surgery allowed for the complete removal of the goiter, with meticulous postoperative hemostasis and closure of only the skin layer with interrupted sutures. The total closure of the surgical layers was postponed until after ECC, following neutralization of sodium heparin with protamine and restoration to a near-normal coagulant state, which allowed for proper surgical hemostasis, verification, and clot removal before final closure. (Figure 11)

Figure 10: Image before anesthetic induction for the first surgical stage (total thyroidectomy), showing a large goiter and the beginning of awake nasotracheal intubation using a nasofibroscope after regional anesthesia. The image also shows the visualization of the carina with the right and left mainstem bronchi after successful passage through the glottis.

Figure 11: Intraoperative image after the closure of the sternotomy, showing verification of hemostasis in the thyroid bed, placement of a drain after reopening the separate skin sutures, before the final closure of the muscle, subcutaneous, and skin layers.

The second stage consisted of achieving cardiac surgery which was performed immediately afterward (Figure 12). The ETO probe was inserted after the thyroidectomy using a video-laryngoscope to avoid trauma to the mouth, esophagus, or accidental intubation. A mechanical aortic valve was implanted under ECC. Perioperative Doppler ETO monitoring was performed, as well as post-ECC monitoring. (Figure 13-20) (Video 1-8).

Figure 12: Intraoperative image after total thyroidectomy, showing the sternal retractor in place with the pericardial sac opened.

Figure 13: Transgastric biventricular short-axis echocardiographic image showing a thickened interventricular septum measuring 2.1 cm, suggestive of left ventricular hypertrophy.

Figure 14: Transesophageal echocardiography (TOE) at the mid-esophageal level, with the sampling window positioned at the distal tips of the mitral leaflets, showing during a transient postoperative passage in sinus rhythm a pseudo-normal flow pattern with an E-wave velocity of 0.70 m/s, an A-wave velocity of 0.30 m/s, an E/A ratio of 1.93 (>1.5), and a calculated deceleration time of 174 ms.

Figure 15: Transesophageal echocardiography (TOE) tissue Doppler at the mid-esophageal level in a 4-chamber view, during a transient postoperative passage in sinus rhythm. The sampling window is positioned at the septal mitral annulus, showing an Ea/Aa ratio <1, indicating impaired relaxation (normalized profile), and an E/Ea ratio of 22, suggesting significantly elevated left ventricular filling pressure.

Figure 16: Transesophageal echocardiography (TOE) at the upper esophageal level, with an antih clockwise rotation and a 60° plane of section. The sampling window is positioned 1 cm before the left superior pulmonary vein confluence, showing normal pulmonary flow with a positive systolic wave (S), a positive diastolic wave, and a small retrograde negative A-wave in the late diastole.

Figure 17: Biplane transesophageal echocardiography (TOE) image in the upper esophageal view centered on the aortic valve, showing a normal diameter of the pulmonary artery trunk measuring 2.6 cm.

Figure 18: Continuous wave Doppler transesophageal echocardiography (TOE) image of the vena contracta in tricuspid regurgitation (reflux within the tricuspid annulus), showing a normal systolic pulmonary artery pressure estimated at 38 mmHg, with a maximum tricuspid regurgitation velocity of 2.60 m/s. The estimated pulmonary artery diastolic pressure (POD) is 10-15 mmHg, and the tricuspid gradient is 27 mmHg.

Figure 19: Transesophageal echocardiography (TOE) at the upper esophageal level, at a 50° oblique plane, with continuous Doppler pointed a few millimeters below the pulmonary valve, showing a maximum average velocity of 0.95 m/s, an average velocity of 0.56 m/s, a maximum mean gradient of 4 mmHg, an isovolumic time (IVT) of 20 cm, and the absence of any detectable pulmonary.

Figure 20: Transgastric continuous Doppler transesophageal echocardiography (TOE) image, at an oblique 135° plane (close to the parasternal long-axis view in transthoracic echocardiography), aligning the ultrasound beam with the aorta, showing a normal postoperative aortic isovolumic time (IVT) of 16.4 cm.