A morphological study of the inferior phrenic arteries on multidetector computed tomography and angiography.

INTRODUCTION: The inferior phrenic artery is a paired artery with a variable origin and course, primarily supplying the diaphragm, but also the suprarenal glands, inferior vena cava, stomach, and oesophagus. The aim of this study is to investigate the origin and course of the inferior phrenic arteries on multidetector computed tomography and angiography. MATERIALS AND METHODS: The anatomy of the inferior phrenic artery was analysed on 2449 multidetector computed tomography scans. Three-dimensional reconstructions were made of the main variations. Additionally, the course and branching pattern of the inferior phrenic artery were descriptively analysed in a cohort of 28 angiograms. RESULTS: In 565 (23.1%) cases the inferior phrenic arteries arose as a common trunk and in 1884 (76.9%) cases as individual vessels. The most common origins of a common trunk were the coeliac trunk (n=303; 53.6%) and abdominal aorta (n=255; 45.1%). The most common origins of the right inferior phrenic artery were the coeliac trunk (n=965; 51.2%), abdominal aorta (n=562; 29.8%) and renal arteries (n=214; 11.4%). The most common origins of the left inferior phrenic artery were the coeliac trunk (n=1293; 68.6%) and abdominal aorta (n=403; 21.4%). CONCLUSION: The inferior phrenic artery has a very variable anatomy. The most common origins of the inferior phrenic artery are the coeliac trunk and its branches, the abdominal aorta, and the renal arteries.

Diaphragmatic weakness after transcatheter arterial chemoembolization of the right inferior phrenic artery for treatment of hepatocellular carcinoma: a comparison of outcomes after N-butyl cyanoacrylate versus gelatin sponge embolization.

BACKGROUND: The inferior phrenic artery (IPA) is the most common extrahepatic feeder for hepatocellular carcinoma (HCC) during transhepatic arterial chemoembolization (TACE). PURPOSE: To compare the incidence of diaphragmatic weakness in patients with HCC after TACE of the right IPA conducted using either N-butyl cyanoacrylate (NBCA) or gelatin sponge particles. MATERIAL AND METHODS: Medical records of 111 patients who underwent TACE of the right IPA using NBCA were retrospectively reviewed and compared with data from 135 patients with IPA embolization using gelatin sponge particles. RESULTS: The incidence of diaphragmatic weakness after the initial TACE procedure did not significantly differ between the groups (NBCA group 16.2%; gelatin sponge group 20.7%; P = 0.458). Five patients in the NBCA group and 11 in the gelatin sponge group showed spontaneous resolution of diaphragmatic weakness after a mean period of 3.5 months. Diaphragmatic weakness developed after the initial follow-up visit in 17 patients from the gelatin sponge group due to repeated TACE of the right IPA (mean 2.4 sessions; range 2-4 sessions), while it spontaneously developed without additional TACE procedures in one patient from the NBCA group. Permanent diaphragmatic weakness was less common in the NBCA than in the gelatin sponge group (12.6% and 25.2%, respectively; P = 0.017). The complete response rate did not significantly differ between the groups (NBCA group 16.2%; gelatin sponge group 25.9%; P = 0.065). CONCLUSION: Use of NBCA rather than gelatin sponge particles for TACE of the right IPA resulted in a lower incidence of permanent diaphragmatic weakness.

A Novel Approach for Hepatic Arterial Reconstruction after Total Pancreatectomy with Common Hepatic Artery Resection Using Inferior Phrenic Artery.

BACKGROUND/AIMS: Because of the anatomical characteristics, pancreatic cancers (PC) can easily invade to visceral vessels such as celiac artery, superior mesenteric artery, common hepatic artery (CHA) and portal vein, which makes curative resection difficult. In this study, we report an R0 resection for locally advanced PC by total pancreatectomy, combined resection of CHA, and reconstruction of hepatic artery using autologous left inferior phrenic artery (IPA). METHODS: A 47-year-old woman with complaints of low back pain was referred to our department. Contrast-enhanced computed tomography revealed a hypo-attenuation tumor of the pancreatic body measuring 70 mm, which completely encased the CHA. When unresectable locally advanced PC was diagnosed, systematic chemotherapy was administrated. After downstaging, she underwent surgery with curative intent. The tumor completely infiltrated the peripheral part of the CHA and gastroduodenal artery. As the tumor also extended to the head of the pancreas, total pancreatectomy and combined resection of CHA were performed. Then the exposed left IPA and proper hepatic artery were anastomosed with a microvascular technique. RESULTS: R0 resection was performed for restoring hepatic arterial flow and the postoperative course was uneventful without any postoperative morbidity. CONCLUSION: Hepatic artery reconstruction using IPA is a simple and safe procedure in selected patients.

The anatomy of the thoracic duct at the level of the diaphragm: A cadaver study.

BACKGROUND: Injury and subsequent leakage of unrecognized thoracic duct tributaries during transthoracic esophagectomy may lead to chylothorax. Therefore, we hypothesized that thoracic duct anatomy at the diaphragm is more complex than currently recognized and aimed to provide a detailed description of the anatomy of the thoracic duct at the diaphragm. BASIC PROCEDURES: The thoracic duct and its tributaries were dissected in 7 (2 male and 5 female) embalmed human cadavers. The level of origin of the thoracic duct and the points where tributaries entered the thoracic duct were measured using landmarks easily identified during surgery: the aortic and esophageal hiatus and the arch of the azygos vein. MAIN FINDINGS: The thoracic duct was formed in the thoracic cavity by the union of multiple abdominal tributaries in 6 cadavers. In 3 cadavers partially duplicated systems were present that communicated with interductal branches. The thoracic duct was formed by a median of 3 (IQR: 3-5) abdominal tributaries merging 8.3cm (IQR: 7.3-9.3cm) above the aortic hiatus, 1.8cm (IQR: -0.4 to 2.4cm) above the esophageal hiatus, and 12.3cm (IQR: 14.0 to -11.0cm) below the arch of the azygos vein. CONCLUSION: This study challenges the paradigm that abdominal lymphatics join in the abdomen to pass the diaphragm as a single thoracic duct. In this study, this occurred in 1/7 cadavers. Although small, the results of this series suggest that the formation of the thoracic duct above the diaphragm is more common than previously thought. This knowledge may be vital to prevent and treat post-operative chyle leakage.

Massive right hemothorax due to idiopathic spontaneous rupture of a phrenic artery following cardiac surgery. / Hemotórax masivo derecho por rotura espontánea idiopática de una arteria frénica tras cirugía cardiaca.

We report a case of a 35-years-old man who presented a massive haemothorax and hypovolemic shock following cardiac surgery, from spontaneous rupture of a phrenic artery. A quick diagnosis and immediate intervention is crucial to manage the patient.

Dietary nitrate supplementation opposes the elevated diaphragm blood flow in chronic heart failure during submaximal exercise.

Chronic heart failure (CHF) results in a greater cost of breathing and necessitates an elevated diaphragm blood flow (BF). Dietary nitrate (NO3‾) supplementation lowers the cost of exercise. We hypothesized that dietary NO3‾ supplementation would attenuate the CHF-induced greater cost of breathing and thus the heightened diaphragm BF during exercise. CHF rats received either 5days of NO3‾-rich beetroot (BR) juice (CHF+BR, n=10) or a placebo (CHF, n=10). Respiratory muscle BFs (radiolabeled microspheres) were measured at rest and during submaximal exercise (20m/min, 5% grade). Infarcted left ventricular area and normalized lung weight were not significantly different between groups. During submaximal exercise, diaphragm BF was markedly lower for CHF+BR than CHF (CHF+BR: 195±28; CHF: 309±71mL/min/100g, p=0.04). The change in diaphragm BF from rest to exercise was less (p=0.047) for CHF+BR than CHF. These findings demonstrate that dietary NO3‾ supplementation reduces the elevated diaphragm BF during exercise in CHF rats thus providing additional support for this therapeutic intervention in CHF.

Visceral subpleural hematoma of the left diaphragmatic surface following left upper division segmentectomy.

BACKGROUND: Pulmonary visceral subpleural hematoma is rare. We report visceral subpleural hematoma of the left diaphragmatic surface following left upper division segmentectomy. This very rare case was difficult to distinguish from thoracic abscess. CASE PRESENTATION: A 68-year-old man with hypertension had undergone video-assisted thoracoscopic left upper division segmentectomy for suspected lung carcinoma. Deep vein thrombosis of the lower leg was identified and edoxaban, a so-called novel oral anticoagulant, was started on postoperative day 7. The chest drainage tube was removed on postoperative day 12 because of persistent air leakage, but fever appeared the same day. Computed tomography revealed a cavity with mixed air and fluid, so antibiotics were started on suspicion of abscess. Computed tomography-guided drainage was attempted, but proved unsuccessful. Fever continued and surgical investigation was therefore performed. Visceral subpleural hematoma was identified under the diaphragmatic surface of the left basal lung. We excised the pleura, then performed drainage and applied running sutures. The parenchyma and visceral pleura were covered with polyglycolic acid sheet and fibrin glue. Edoxaban was restarted on postoperative day 12 of video-assisted thoracoscopic surgery and no recurrence of hematoma has been revealed. CONCLUSIONS: Visceral subpleural hematoma after thoracic surgery is extremely rare. Furthermore, correct diagnosis was difficult and surgery offered a good diagnostic and therapeutic procedure.

Down-regulation of N-deacetylase-N-sulfotransferase-1 signaling in the developing diaphragmatic vasculature of nitrofen-induced congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) has been attributed to various developmental abnormalities of the underlying tissue components. N-deacetylase-N-sulfotransferase-1 (Ndst1) is a strongly expressed biosynthetic enzyme in endothelial cells, which has recently been identified as an important factor during diaphragmatic vascularization. Loss of endothelial Ndst1 has been demonstrated to cause angiogenic defects in the developing diaphragm and disrupt normal diaphragmatic development. Furthermore, deficiency of Ndst1 diminishes the expression of slit homolog 3 (Slit3), a known CDH-related gene that has been associated with reduced vascular density and muscle defects in the diaphragm of Slit3-/- mice. We hypothesized that expression of Ndst1 and Slit3 is decreased in the diaphragmatic vasculature of fetal rats with nitrofen-induced CDH. METHODS: Time-mated rats received either nitrofen or vehicle on gestational day 9 (D9). Fetal diaphragms were microdissected on D13, D15 and D18, and divided into control and nitrofen-exposed specimens. Gene expression levels of Ndst1 and Slit3 were assessed using qRT-PCR. Immunofluorescence-double-staining for Ndst1 and Slit3 was performed to evaluate protein expression and localization. RESULTS: Relative mRNA expression of Ndst1 and Slit3 was significantly decreased in pleuroperitoneal folds (D13), developing diaphragms (D15) and fully muscularized diaphragms (D18) of nitrofen-exposed fetuses compared to controls. Confocal-laser-scanning-microscopy revealed markedly diminished Ndst1 and Slit3 expression in endothelial cells within the diaphragmatic vasculature on D13, D15 and D18 compared to controls. CONCLUSIONS: Down-regulation of Ndst1 signaling in the developing diaphragm may impair endothelial cell migration and angiogenesis, thus leading to defective diaphragmatic vascular development and CDH. LEVEL OF EVIDENCE: Ib.

Large Sized Left Inferior Phrenic Artery and Parahiatal Type of Diaphragmatic Hernia Generating Confusion During Robotic Surgical Repair.

INTRODUCTION: As an advanced minimally invasive surgical procedure, the repair of the diaphragmatic hernia may sometimes be very challenging especially when the anatomy is unclear. MATERIALS AND METHODS: We are presenting a rare case of a parahiatal hernia defect repair where the understanding of the anatomy was complicated by the presence of an unusual large sized left inferior phrenic artery. The Da Vinci surgical platform was used to perform the entire procedure. Hernia sac dissection, identification of the crura, primary closure of the defect, and use of biologic mesh reinforcement were the main steps performed in the usual manner for hernia repair. In addition, the use of intraoperative ultrasound was of great utility to clarify the vascular anatomy. RESULTS: The additional time required for the intraoperative ultrasound and identification of the vascular anatomy has increased the duration of the procedure that otherwise was uneventful. The accurate identification of the anatomy allowed for a safe surgical outcome. The postoperative course was favorable and patient was free of symptoms at 1-month follow-up. CONCLUSION: The challenge of the repair of this rare, parahiatal type of diaphragmatic hernia where a large sized left inferior phrenic artery was also encountered was successfully mitigated by the use of the intraoperative Doppler ultrasound and by compliance with the basic steps of the procedure.

Anomalous Feeding of the Left Upper Lobe.

We report the case of a 53-year-old woman who presented with massive hemoptysis. Computed tomographic angiography revealed an anomalous vessel arising from the abdominal aorta, coursing anteriorly and through the diaphragm, and feeding the left upper lobe. At operation the vessel was found to anastomose to the left upper lobe lingula, which contained multiple vascular abnormalities and arteriovenous fistulas. The vessel was ligated, and the affected portion of the left upper lobe was resected. Anomalous systemic arterial supply of an upper lobe is an especially rare form of a Pryce type 1 abnormality. Recognition of these unusual anatomic variants is crucial to successful treatment and avoidance of adverse events.

Extra-hepatic feeding arteries of hepatocellular carcinoma: An investigation based on intra-arterial CT aortography images using an angio-MDCT system.

OBJECTIVES: We investigated the frequencies and factors associated with the presence of extra-hepatic feeding arteries (EHFAs) of hepatocellular carcinoma (HCC) using intra-arterial CT aortography images. METHODS: A total of 173 patients with HCC who underwent transarterial chemoembolization (TACE) in our institution between January 2013 and March 2015 were enrolled. The types of EHFAs were evaluated by CT aortography images using an apparatus that combines multidetector-row computed tomography and angiography system. In addition, factors associated with the presence of EHFAs were determined. RESULTS: EHFAs were present in 22 (12.7%) patients with HCC. EHFAs most frequently branched from the right inferior phrenic artery (n=19), while others branched from the right adrenal artery (n=2), right renal artery (n=2), right internal thoracic artery (n=2), branches of the superior mesenteric artery (n=1), and an unknown artery from the aorta (n=1). Factors significantly associated with the presence of EHFAs in multivariate analysis were tumor size≥30mm (odds ratio (OR), 5.233 [95% confidence interval (CI), 1.507-17.413]; p=0.009) and number of prior TACE treatments≥3 (OR, 6.847 [95% CI, 1.928-24.311]; p=0.003). CONCLUSIONS: EHFAs of HCC were assessed with CT aortography images. Repeat TACE treatments and large tumor size were risk factors for the presence of EHFAs.

Orthotopic transplantation of a tissue engineered diaphragm in rats.

The currently available surgical options to repair the diaphragm are associated with significant risks of defect recurrence, lack of growth potential and restored functionality. A tissue engineered diaphragm has the potential to improve surgical outcomes for patients with congenital or acquired disorders. Here we show that decellularized diaphragmatic tissue reseeded with bone marrow mesenchymal stromal cells (BM-MSCs) facilitates in situ regeneration of functional tissue. A novel bioreactor, using simultaneous perfusion and agitation, was used to rapidly decellularize rat diaphragms. The scaffolds retained architecture and mechanical properties and supported cell adhesion, proliferation and differentiation. Biocompatibility was further confirmed in vitro and in vivo. We replaced 80% of the left hemidiaphragm with reseeded diaphragmatic scaffolds. After three weeks, transplanted animals gained 32% weight, showed myography, spirometry parameters, and histological evaluations similar to native rats. In conclusion, our study suggested that reseeded decellularized diaphragmatic tissue appears to be a promising option for patients in need of diaphragmatic reconstruction.

Inferior phrenic artery pseudoaneurysm complicating drug-induced acute pancreatitis.

Inferior phrenic artery (IPA) pseudoaneurysm is an extremely rare complication of chronic pancreatitis with only three cases reported in the literature so far. It is a serious condition that can be life-threatening if not diagnosed promptly. Recent advances in endovascular interventions made angiography with embolisation the modality of choice for diagnosis and treatment. We presented the first report of a case of ruptured IPA pseudoaneurysm complicating a drug-induced acute pancreatitis that was successfully treated by transcatheter arterial embolisation. Despite its rarity, rupture of pseudoaneurysm due to drug-induced pancreatitis should be suspected and included in the differential diagnosis when associated with haemodynamic instability.

Heparan sulfate deficiency disrupts developmental angiogenesis and causes congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a common birth malformation with a heterogeneous etiology. In this study, we report that ablation of the heparan sulfate biosynthetic enzyme NDST1 in murine endothelium (Ndst1ECKO mice) disrupted vascular development in the diaphragm, which led to hypoxia as well as subsequent diaphragm hypoplasia and CDH. Intriguingly, the phenotypes displayed in Ndst1ECKO mice resembled the developmental defects observed in slit homolog 3 (Slit3) knockout mice. Furthermore, introduction of a heterozygous mutation in roundabout homolog 4 (Robo4), the gene encoding the cognate receptor of SLIT3, aggravated the defect in vascular development in the diaphragm and CDH. NDST1 deficiency diminished SLIT3, but not ROBO4, binding to endothelial heparan sulfate and attenuated EC migration and in vivo neovascularization normally elicited by SLIT3-ROBO4 signaling. Together, these data suggest that heparan sulfate presentation of SLIT3 to ROBO4 facilitates initiation of this signaling cascade. Thus, our results demonstrate that loss of NDST1 causes defective diaphragm vascular development and CDH and that heparan sulfate facilitates angiogenic SLIT3-ROBO4 signaling during vascular development.

Rare case of the trunk of the inferior phrenic arteries originating from a common stem with a superior additional left renal artery from the abdominal aorta.

We describe in this article a rare case of a 39-year-old male with an inferior phrenic arteries trunk (IPAaT) originating from a common stem with a superior additional left renal artery (SAdLRA) from the abdominal aorta as revealed by routine multidetector computed tomography angiography. The IPAaT with an endoluminal diameter at the origin of 2.8 mm had an upward path with a total length of 18.4 mm, forking to the right inferior phrenic artery and left inferior phrenic artery. These two arteries had an endoluminal diameter at the origin of 1.7 mm and 2.0 mm, respectively. The presence of the common stem of the IPAaT with a SAdLRA and the length of the IPAaT complicate selective chemoembolization of the liver parenchyma.

Pseudoaneurysm of the inferior phrenic artery presenting as an upper gastrointestinal bleed by directly rupturing into the stomach in a patient with chronic pancreatitis.

Pseudoaneurysms occurring in patients with chronic pancreatitis are associated with significant morbidity and mortality. These pseudoaneurysms occur more commonly in the splenic, pancreaticoduodenal, and gastroduodenal arteries. Upper gastrointestinal bleeding (UGIB) due to pseudoaneurysms in patients with pancreatitis with pseudocyst usually presents as hemosuccus pancreaticus. However, pseudoaneurysm directly perforating the gastrointestinal tract and presenting as UGIB is a rare complication. We report here the first case of UGIB from the inferior left phrenic artery pseudoaneurysm rupturing directly into the stomach of a patient with chronic pancreatitis.

Anatomy of the normal diaphragm.

The thoracic diaphragm is a dome-shaped septum, composed of muscle surrounding a central tendon, which separates the thoracic and abdominal cavities. The function of the diaphragm is to expand the chest cavity during inspiration and to promote occlusion of the gastroesophageal junction. This article provides an overview of the normal anatomy of the diaphragm.