Uniportal VATS Treatment of Symptomatic Pericardial Cyst

Pericardial cysts are benign and rare congenital malformations with an incidence of 1 in 100,000, representing about 7% of mediastinal masses [1]. Pericardial cysts— as well as pericardial diverticula— are caused by an abnormal fusion of mesenchymal lacunae, although cysts are more common than diverticula, with a relative ratio of 3:1 [2].

Diverticula can be differentiated from cysts because they modify their size with changes in body position or breathing. On the contrary, cysts present a constant size but may alter in shape [3]. Pericardial cysts are often reported in the fourth decade of life with a male predominance (3:2), and frequently are located at the right costophrenic angle (70%), followed by the left costophrenic angle (22%), and posterior superior or anterior mediastinum [4]. Although pericardial cysts are frequently stable in size, they can enlarge slowly over time.  The most commonly reported symptoms are shortness of breath, chest discomfort, and cough. Palpitations and arrhythmias have also been reported [5].

By echocardiography, pericardial cysts are often diagnosed as a hypoechoic and loculated space close to the cardiac border that may distort the normal shape of adjacent cardiac structures [6]. By cardiac computed tomography (cCT) they appear as well-demarcated, thin-walled, homogenous, nonenhancing masses without internal septa [7], while during cardiac magnetic resonance imaging (cMRI) they show low to intermediate signal intensity on T1-weighted sequences, and high signal intensity on T2-weighted sequences [8].

When asymptomatic, pericardial cysts can be monitored by serial cCT or cMRI every one to two years [9]. In contrast, if patients become symptomatic, treatment is required by percutaneous aspiration of the cyst or by videothoracoscopic surgery, if technically feasible [10].

Otto Pickhardt from Lenox Hill Hospital in New York City, New York, is usually credited with the first resection of a pericardial cyst in 1931 via thoracotomy through the left eighth intercostal space [11]. Due to encouraging reports on such pioneering procedures, many thoracic surgeons developed an interest in the diagnosis and treatment of pericardial cysts and diverticula.

The presence of a thin-walled translucent cyst containing crystal-clear fluid gave rise to calling them “spring water cysts.” In fact, Greenfield and colleagues from Mount Sinai Hospital in New York City introduced the new term into the medical literature, describing a cyst filled with “crystal-clear fluid of watery consistence” in 1943 [12]. Thus, “spring water cyst” soon became an established metaphor for pericardial cysts [13].

Here, the authors report of a 59-year-old man who presented with a cough and supraventricular extrasystoles and whose CT scan disclosed a well-defined round cystic lesion, 58 x 45 mm in diameter. It was without contrast enhancement, was PET FDG negative, and was confirmed by MRI. Echocardiography disclosed the cystic lesion, immediately adjacent to the right ventricle, the pulmonary artery, and the pulmonary valve, without any infiltration.

The patient underwent uniportal left videothoracoscopy. Exploration disclosed a well-defined cystic lesion, without infiltration of the lung or other adjacent structures. Needle puncture of the cystic wall confirmed the absence of retained blood in the cyst and allowed a gradual deflation of the lesion, thus allowing effective grasping without any damage. The cyst was then incised and “crystal-clear fluid of watery consistence,” as first described by Greenfield and colleagues in 1943, was drained. A fluid specimen was collected for cytologic and microbiologic examination. The cyst was properly inspected and then a wide fenestration was performed with ultrasonic shears to obtain a histologic specimen and to avoid cyst recurrence. The course of the phrenic nerve was carefully observed and respected to avoid phrenic nerve injury. The postoperative course was uneventful and the patient was discharged on postoperative day three in good clinical condition.

References

1. Tower-Rader A, Kwon D. Pericardial masses, cysts and diverticula: a comprehensive review using multimodality imaging. Prog Cardiovasc Dis. 2017;59(4):389-397.
2. Mazer ML. True pericardial diverticulum; report of a case, with safe operative removal. Am J Roentgenol Radium Ther. 1946;55:27-29.
3. Le Roux BT. Pericardial coelomic cysts. Thorax. 1959;14(1):27-35.
4. Feigin DS, Fenoglio JJ, McAllister HA, Madewell JE. Pericardial cysts. A radiologic–pathologic correlation and review. Radiology. 1977;125(1):15-20.
5. Vlay SC, Hartman AR. Mechanical treatment of atrial fibrillation: removal of pericardial cyst by thoracoscopy. Am Heart J. 1995;129(3):616-618.
6. Yared K, Baggish AL, Picard MH, Hoffmann U, Hung J. Multimodality imaging of pericardial diseases. JACC Cardiovasc Imaging. 2010;3(6):650-660.
7. Demos TC, Budorick NE, Posniak HV. Benign mediastinal cysts: pointed appearance on CT. J Comput Assist Tomogr. 1989;13(1):132-133.
8. Frank H, Globits S. Magnetic resonance imaging evaluation of myocardial and pericardial disease. J Magn Reson Imaging. 1999;10(5):617-626.
9. Klein AL, Abbara S, Agler DA, et al. American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with pericardial disease: endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2013;26(9):965-1012.e15.
10. Najib MQ, Chaliki HP, Raizada A, Ganji JL, Panse PM, Click RL. Symptomatic pericardial cyst: a case series. Eur J Echocardiogr. 2011;12(11):E43.
11. Pickhardt OC. Pleuro-diaphragmatic cyst. In: Transactions of the New York Surgical Society-Stated Meeting held April 12, 1933. Ann Surg. 1934;99(5):814-816.
12. Greenfield L, Steinberg L, Touroff ASW. Spring water cyst of the mediastinum. J Thorac Surg. 1943;12:495-502.
13. Schweigert M, Dubecz A, Beron M, Ofner D, Stein HJ. The tale of spring water cysts: a historical outline of surgery for congenital pericardial diverticula and cysts. Tex Heart Inst J. 2012;39(3):330-334.