Introduction
Hepatopulmonary fusion is an extremely rare congenital defect characterised by physical connection between liver and lung. It can be found in patients with diaphragm malformation, especially with right-sided congenital diaphragmatic hernia. This connection ranges from fibromuscular to vascular and even parenchymal fusion. Hepatopulmonary fusion is very rare and found in three of every thousand cases of congenital diaphragmatic hernia. Mortality in hepatopulmonary fusion is reported to be 49%. Reference Ferguson1
Hypoplastic left heart syndrome, a once fatal diagnosis, has become survivable with the development of three-staged single ventricle palliative procedures. Surgical single-ventricle palliation includes the Norwood, Glenn, and Fontan operations and allows some patients to live into adulthood. Reference Kritzmire, Thomas and Horenstein2
CHD is often associated with other congenital anomalies, including congenital diaphragmatic hernia. It is estimated that 15% of congenital diaphragmatic hernia cases also have CHD. Reference Fraser, Hill and Wallace3 Hypoplastic left heart syndrome in association with other anomalies has been shown to result in worse outcomes. The survival rate for patients with comorbid hypoplastic left heart syndrome and congenital diaphragmatic hernia is 0–5%. Reference Kanade, Shazly and Ruano4,Reference Graziano5 We report the first case of surgically palliated hypoplastic left heart syndrome in a patient with hepatopulmonary fusion.
Methods
A review of the literature was done using both PubMed and Google using the term “hepatopulmonary fusion.” Every case report, case series, and review of the literature found was evaluated for coexisting hypoplastic left heart syndrome. Survival was determined by what was reported in the published case. For the purposes of this literature review, all cases were included regardless of journal or nation of publication.
Literature review
There has been one case of hypoplastic left heart syndrome and simultaneous hepatopulmonary fusion reported in the literature. Reference Shapiro and Metlay6 Notably, this patient’s hepatopulmonary fusion consisted of a stalk coming off the diaphragm in the absence of other diaphragmatic abnormalities. This patient did not undergo single ventricle palliation and subsequently died from heart failure. There is a report of a patient with hepatopulmonary fusion, “borderline left heart hypoplasia,” and several other anomalies who did not undergo surgical palliation of his cardiac malformations and subsequently died. Reference Breysem, Vanhaesebrouck, Gewillig, Dymarkowski and Smet7
Case
The patient was prenatally diagnosed with hypoplastic left heart syndrome (mitral atresia/aortic atresia type) and was started on prostaglandins after postnatal confirmation. After arrival from the outside hospital, there was concern for a congenital diaphragmatic hernia based on X-ray.
It was determined that the patient would need repair of the congenital diaphragmatic hernia prior to cardiac intervention. At 6 days of age, he underwent exploratory thoracotomy when an “odd type of Morgagni hernia” rather than the expected typical congenital diaphragmatic hernia was found. The patient was determined to have favourable anatomy for a Norwood procedure rather than a hybrid Norwood procedure, given that the patient had neither late recognition of hypoplastic left heart syndrome with pulmonary overcirculation nor significant prematurity – each criterion for a hybrid Norwood at our centre. At 12 days of age, the patient underwent a Norwood-type arch reconstruction with a 6 mm Sano right ventricle-to-pulmonary artery shunt and an atrial septectomy.
At 1 month of age, the patient had an exploratory laparotomy, which revealed possible hepatopulmonary fusion. Vessels connecting an abnormally shaped right hepatic lobe were visualised pierced the right diaphragm. However, the patient was stable prior to surgery, and the decision was made not to alter the apparent blood flow connecting the liver with the lung. Discussion following cardiac catheterisation and intervention determined that the vascular connection and diaphragmatic abnormality needed to be addressed surgically (see Figures 1 and 2). Catheterisation as well as temporary clamping failed to demonstrate haemodynamic significance of the known vasculature perforating the diaphragm from the lungs. At 4 months of age, the patient underwent a ligation of the perforating diaphragmatic vessels and diaphragmatic plication. The diaphragm was found to insert abnormally high on the chest wall and was plicated 2 cm inferior to its prior insertion. No hernia was found during the surgery.
Axial CT image of superiorly-displaced liver prior to diaphragmatic plication.
Coronal CT image of superiorly displaced liver prior to diaphragmatic plication.
After multidisciplinary and multicenter discussion, which included reviewing imaging and catheterisation-obtained haemodynamics, the patient was determined to have a low chance of survival without proceeding with stage 2 of single ventricle palliation. Despite being high risk for the operation, it was thought that disconnecting the diaphragm and reattaching it further caudally would allow right lung expansion and better oxygenation. He was thought to have sufficient lung parenchyma to survive the passive flow state of a bidirectional Glenn and underwent this procedure as well as a bilateral pulmonary arterioplasty at 5 months of age. The diaphragm was detached and reattached inferiorly to expand the hemithorax and provide space for growth of the right lung. The surgery was successful and post-op echocardiogram demonstrated normal ventricular systolic function with mild tricuspid regurgitation.
The patient continued to be repeatedly hospitalised with chronic respiratory failure and was in discussion to receive a tracheostomy tube. He ultimately succumbed to septic shock at 15 months of age.
Discussion
Hepatopulmonary fusion is an extraordinarily rare pathology with high reported mortality, often reported as 49%. Reference Ferguson1 The reason for this high mortality is likely multifactorial, including but not limited to operative complications, lung hypoplasia and associated congenital malformations. The risk of operation in these patients may discourage intervention, and there is no consensus as to whether these patients should undergo surgery; likely, the decision should be made on a case-by-case basis, as this condition presents in vastly different ways.
In the past few decades, the medical world has developed a suggested timeline for palliation in hypoplastic left heart syndrome patients: Norwood operation at a few days of life, Glenn at 3-6 months of life, and Fontan at 2–6 years of life. Reference Kritzmire, Thomas and Horenstein2 Given comorbidities and heterogeneity in this population as well, exceptions absolutely occur, and much of the decision-making for these patients is made with families and multidisciplinary teams.
A brief review of the literature on hepatopulmonary fusion seems dismal, with high morbidity and mortality rates for these patients. However, much of the mortality may not be due to the hepatopulmonary fusion itself but rather other factors. Although our patient ultimately died, his operations allowed him to survive long enough to discuss long-term planning. In his specific case, his prolonged hospitalisation and decreased reserve due to chronic respiratory and cardiac failure were likely the reasons for his ultimate demise, rather than hepatopulmonary fusion itself.
Acknowledgements
None.
Financial support
This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Competing interests
None.
Limitations
This review only looked at only published cases and therefore has an inherent publication bias.
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