Complete left pericardial defect with dual passage of the phrenic nerve: a challenge to the widely accepted embryogenic theory

A Case of Incidentally Discovered Congenital Complete Pericardial Defect during Lobectomy for Lung Cancer: A Case Report and Literature Review

An 82-year-old male patient underwent a left upper lobectomy with anterolateral thoracotomy for lung cancer. Although a complete left-pericardial defect was observed during surgery, the pericardial repair was not performed because the left lower lobe remained and the heart was considered stable. Postoperative pathological examination revealed primary synchronous double-lung squamous-cell carcinoma (pathological stage pT2a(2)N0M0 stage IB). He was discharged without complications on postoperative day 8. Leftward displacement of the heart and left diaphragmatic elevation, suspected of phrenic-nerve paralysis, were found in the chest X-ray after discharge. However, the patient's overall condition remained unaffected at the 5-month postoperative follow-up. To assess the need for pericardial repair, we compared cases of complete pericardial defects observed during lobectomy or pneumonectomy reported in the literature. Only one of 12 cases occurred postoperative death despite pericardial repair, and that case combined pectus excavatum and pericardial defects. Our assessment indicated that pericardial repair might not be necessary, excluding complex cases.

Multimodality Imaging Approach Evaluation of the Congenital Pericardial Defect: a Contemporary Review

PURPOSE OF REVIEW

This review presents the etiology, clinical manifestations, diagnostic approach, and treatment of congenital pericardial defects. It also highlights the critical role of echocardiography, cardiac computed tomography (CCT), and cardiac magnetic resonance (CMR) in the diagnosis and management approach.

RECENT FINDINGS

Congenital pericardial defects are rare. Although most cases are found incidentally, some cases could potentially be associated with serious outcomes including sudden cardiac death. The diagnosis is often challenging due to non-specific clinical manifestations and electrocardiogram findings. Echocardiography is the first-line imaging investigation for the evaluation of this condition. Advanced cardiac imaging modalities, including CCT and CMR, play important adjuvant roles in establishing the diagnosis and assists with prognostication.

Case series, contemporary review and imaging guided diagnostic and management approach of congenital pericardial defects

Objective

Congenital pericardial defect (CPD) is a rare entity with an estimated frequency of 0.01%–0.04%. The recognition of this anomaly is important since it can be associated with serious complications. The aim of this study and review was to describe clinical and imaging features that help in establishing the diagnosis of this condition.

Methods

We retrospectively reviewed all adult patients at the Cleveland Clinic Health System with the diagnosis of CPD between the years 2000 and 2015. Baseline clinical characteristics, clinical manifestations, ECG, transthoracic echocardiography (TTE), cardiac CT and cardiac magnetic resonance (CMR) images were reviewed.

Results

Eight patients were included in the study. Sixty-three percent of patients were males with mean age at diagnosis of 48 years, 63% had a partial pericardial defect on the left side and right ventricular (RV) dilation on TTE. Three patients had CMR. Levocardia was present in all CMRs. One patient had greater than 60° clockwise rotation and none of the CMRs showed ballooning of the left ventricular apex. One patient required surgical pericardioplasty. The remaining seven patients had a median follow-up of 17.3 months (5–144.9 months) and all remained asymptomatic.

Conclusion

CPDs are more likely to be partial on the left side and patients often have RV dilation on the TTE and levocardia on CMR. Most patients remain stable and do not require surgical intervention. TTE and CMR play an important role in making the diagnosis of this anomaly.

Lobectomy for Lung Cancer With Congenital Pericardial Defect

A congenital complete pericardial defect is a rare and often asymptomatic condition that may be diagnosed intraoperatively. While performing lung lobectomy in patients with this condition, surgeons must exercise more caution than with standard lobectomies. Additional points of consideration include the use of surgical instruments to ensure a clear operative field, vascular treatment for pulmonary veins, confirmation of the phrenic nerve location, and determination of the need to repair the pericardial defect. This report describes a rare case of a complete left pericardial defect that was detected in a man with lung cancer during left upper lobectomy.

Congenital absence of the right pericardium: embryology and imaging

Though congenital pericardial absence is often asymptomatic, complications can be life threatening. To date, few short case reports, primarily from the pre-CT and MR era, describe congenital absence of the right pericardium. We present a more comprehensive discussion of the embryologic derangements causing such defects and offer an up-to-date review of characteristic radiologic findings. Recognition of characteristic imaging findings of congenital pericardial absence is crucial in guiding diagnosis and management.

Wt1 and retinoic acid signaling in the subcoelomic mesenchyme control the development of the pleuropericardial membranes and the sinus horns

RATIONALE

The cardiac venous pole is a common focus of congenital malformations and atrial arrhythmias, yet little is known about the cellular and molecular mechanisms that regulate its development. The systemic venous return myocardium (sinus node and sinus horns) forms only late in cardiogenesis from a pool of pericardial mesenchymal precursor cells.

OBJECTIVE

To analyze the cellular and molecular mechanisms directing the formation of the fetal sinus horns.

METHODS AND RESULTS

We analyzed embryos deficient for the Wt1 (Wilms tumor 1) gene and observed a failure to form myocardialized sinus horns. Instead, the cardinal veins become embedded laterally in the pleuropericardial membranes that remain tethered to the lateral body wall by the persisting subcoelomic mesenchyme, a finding that correlates with decreased apoptosis in this region. We show by expression analysis and lineage tracing studies that Wt1 is expressed in the subcoelomic mesenchyme surrounding the cardinal veins, but that this Wt1-positive mesenchyme does not contribute cells to the sinus horn myocardium. Expression of the Raldh2 (aldehyde dehydrogenase family 1, subfamily A2) gene was lost from this mesenchyme in Wt1(-/-) embryos. Phenotypic analysis of Raldh2 mutant mice rescued from early cardiac defects by retinoic acid food supply revealed defects of the venous pole and pericardium highly similar to those of Wt1(-/-) mice.

CONCLUSIONS

Pericardium and sinus horn formation are coupled and depend on the expansion and correct temporal release of pleuropericardial membranes from the underlying subcoelomic mesenchyme. Wt1 and downstream Raldh2/retinoic acid signaling are crucial regulators of this process. Thus, our results provide novel insight into the genetic and cellular pathways regulating the posterior extension of the mammalian heart and the formation of its coelomic lining.

Partial pericardial defect incidentally discovered during coronary bypass surgery

A 71-yr-old male patient with three vessel coronary artery disease underwent a coronary artery bypass graft. The patient was found to have a large pericardial defect at the apex of the heart that measured approximately 18 cm in circumference. The edge of the pericardial defect impinged on the epicardial coronary arteries. The left phrenic nerve descended via the dorsal boundary of the pericardial defect. Following coronary artery bypass grafting, the pericardial defect was repaired with a polytetrafluorethylene patch. The patient had an uncomplicated postoperative course.

Congenital Defects of the Pericardium

Congenital defects of the pericardium are rare, but when they are reported they are frequently associated with other cardiac lesions. We describe a case of partial pericardial defect found incidentally at surgery for closure of an ostium primum atrial septal defect. Proposed mechanisms of pericardial defect development are discussed and we suggest that associations with congenital and acquired heart disease are mostly circumstantial.

Congenital pericardial defect: report of two cases and literature review

The authors report two cases of congenital pericardial defect and emphasize the role of MRI as a diagnostic tool. A review of the development of the pericardium and of the various possible explanations dealing with these abnormalities is then presented. Finally, clinical data and diagnosis and therapeutic options are discussed.

Congenital foramen of the left pericardium

Congenital foramen of the left parietal pericardium is uncommon. The condition has the potential to cause angina pectoris, myocardial infarction, or even death. Forty-three confirmed cases have been retrieved from the English language literature, and a case report of "life-threatening" herniation of the heart is here added. The diagnosis, made at a mean age of 20 years (range 2 to 48), was five times more common in men. In 5 fatal cases, the heart had become incarcerated. In the remainder of cases, one-third were asymptomatic, and two-thirds suffered a chest complaint that prompted diagnosis. Chest discomfort, dyspnea, and syncope were the most common symptoms. The most common finding at surgery, which 34 patients underwent, was a foramen at the base of the heart through which the left atrial appendage had herniated. In eight instances, the rim of the defect lay upon and compressed the coronary circulation. Measures to remedy the disorder have included a variety of operations, some to enlarge the defect, others to close it, amputation of the atrial appendage, and, in two cases, myocardial revascularization. Surgery is appropriate in the majority of symptomatic patients and in all who are at risk for ventricular herniation.