Abdominal aortic aneurysm in a premature neonate with disseminated candidiasis: ultrasound and angiography

[Successful endovascular treatment of thoracic aortic aneurysm secondary to infection of the umbilical artery catheter in preterm infants]

Aortic aneurysms (AA) in the paediatric population are uncommon. The use of umbilical catheters in neonates has been associated with infections and, on some occasions, the formation of aortic aneurysms. The surgical repair of these aneurysms is one type of treatment; however, percutaneous intervention with stents could provide an alternative treatment route, with fewer complications. The aim of this report is to present the therapeutic scope of a hybrid procedure, in which the combined surgical and percutaneous technique offers a less invasive alternative to open surgery for the repair of aortic aneurysms or their main branches.

CLINICAL CASE

The case concerns a pre-term newborn of 30 weeks weighing 1,335 g. An umbilical catheter was introduced, which was withdrawn at 14 days due to an infection. It developed as Staphylococcus aureus with sepsis. The echocardiogram and Angio-CT confirmed AA, which were managed using a hybrid procedure of surgery and the endovascular implantation of 2 coated stents (Atrium V12 XR Medical Corp, Hudson, NH). The post-procedure clinical follow-ups, including abdominal echo-tomography, confirmed the success of the treatment.

CONCLUSION

The endovascular aortic aneurysm repair procedure in premature newborns may be considered when deciding treatment of this disease, and could avoid the risks associated with open surgery. However, follow-up and monitoring is required while the patient grows up, due to the possibility that the implanted stents require re-dilating. The outcomes of neonatal endovascular procedures in the future are unknown.

Effects of umbilical arterial catheterization on mesenteric hemodynamics

Impairment of mesenteric blood flow due to the use of umbilical artery catheters (UAC) may increase the risk of necrotizing enterocolitis (NEC) in newborn infants. We used Duplex Doppler sonography to investigate the degree of vessel obstruction due to UAC and their effect on visceral hemodynamics in 12 newborn infants. Ultrasonography was performed before and immediately after removal of the UAC, which was positioned above the ostia of the celiac and superior mesenteric arteries (SMA). Vessel diameter, peak systolic blood flow velocity (PSFV), end diastolic blood flow velocity (EDFV), and Pourcelot's resistance index (RI) were measured in the celiac trunk and the SMA within 1 cm of their origins. Removal of the UAC led to a significant increase in mean PSFV (celiac trunk: 50 cm/s +/- 15 vs 62 cm/s +/- 0.22, P < 0.05; SMA: 52 cm/s +/- 0.17 vs 72 cm/s +/- 0.21, P < 0.05). RI increased from 0.7 +/- 0.14 to 0.74 +/- 0.13 and from 0.73 +/- 0.1 to 0.76 +/- 0.13 for the celiac trunk and SMA, respectively. The EDFV and vessel diameters did not change significantly after UAC removal. Our results suggest that UAC cause a decrease in mesenteric blood flow. Therefore, their use in hemodynamically unstable neonates or in those with gastrointestinal disease should be very carefully considered.

Bilateral splenorenal bypass and axillofemoral graft for management of juxtarenal mycotic aneurysm

The principles of treatment of mycotic aortic aneurysms are not well established and the optimal method of revascularization--extra-anatomic bypass or in situ grafting--is still debated. Infection of the juxtarenal or suprarenal aorta poses an additional challenge in management because of the requirement for visceral revascularization. The case of a 73-year-old man is reported who developed several mycotic aneurysms of the juxtarenal, infrarenal aorta and right main iliac artery following a Candida infection. He was successfully treated with suprarenal aortic ligation, aneurysmal excision, splenorenal bilateral bypass and systemic antifungal therapy. The patient subsequently underwent extra-anatomic revascularization of the lower extremities with a left axillobifermoral bypass involving a polytetrafluoroethylene graft.

Candida infection with aneurysm formation in the juxtarenal aorta

We report a case of an elderly patient with diabetes with calcific aortic atherosclerosis in whom a juxtarenal aortic aneurysm developed after Candida fungemia. Our approach included extra-anatomic reconstruction of the lower extremities, hepatorenal arterial bypass of the right kidney, retroperitoneal excision of the infected aortic segment, intravenous administration of amphotericin B after operation, and lifetime suppression of Candida organisms with oral antifungal therapy.

Mycotic thromboaneurysmal disease of the abdominal aorta in preterm infants: its natural history and its management

Five infants with mycotic complications of umbilical artery catheterization were evaluated with abdominal ultrasound and followed serially to document their natural history. Methicillin-resistant Staphylococcus aureus was always the infecting organism. There were one female and four male infants and they weighed between 900 and 1,200 g at birth. While two of the catheters were positioned in the abdominal aorta, three were located above the diaphragm. The predominate signs and symptoms included: thrombocytopenia, unexplained anemia, renal failure, hypertension, and embolic phenomena to the toes. Real-time ultrasound always proved sufficient for diagnosis. Serial studies detected the initial aortic thrombosis in three patients and accurately documented its progression to aneurysmal disease over 10 days in one patient and 17 days in another. Three of the infants were diagnosed with aneurysms at their initial examination. Of the five patients, three were treated nonoperatively and died of complications of their aortic disease. One patient was discovered at operation to have necrotic ischemic intestine. Aortic repair was postponed and he died of septic complications. The remaining patient underwent a PTFE interposition graft and survived for 6 months, dying of pulmonary failure with autopsy confirmed graft patency.

Pharmacokinetics of intra-arterial indomethacin treatment for patent ductus arteriosus

We present pharmacokinetic data of prolonged, intra-arterial indomethacin treatment (i.e. induction plus maintenance dose) for symptomatic patent ductus arteriosus (sPDA) in 26 ventilated premature infants. sPDA was assessed by two-dimensional and pulsed Doppler echocardiography. Permanent ductal closure occurred in 20 (76%) infants. Plasma levels of indomethacin were 1.18 +/- 0.74; 1.8 +/- 1.0; 1.51 +/- 0.93 and 1.25 +/- 0.98 micrograms/ml (mean +/- SD) at 12, 24, 48 and 72 h after initial dose administration. All except one patient who responded with ductal closure, showed plasma levels above 0.25 microgram/ml throughout the 3 day treatment period and no case of sPDA reopening was noted. Although target concentrations over time were not defined, the data indicate that the maintenance levels measured were within the therapeutic range. A negative correlation was found for plasma drug levels and postnatal age (r = 0.52; P less than 0.01). Volume of drug distribution was 0.23 +/- 0.18 l/kg, total clearance 0.1 +/- 0.11 ml/min and elimination constant 0.06 +/- 0.05 h-1 (mean +/- SD). The great variation in pharmacokinetic data reflects the heterogeneity of the population studied with respect to extracellular fluid space, cardiovascular status, serum protein and other parameters.

Aneurysms of the abdominal aorta in the neonate and infant

We report a case of aneurysm of the infrarenal abdominal aorta from septic umbilical artery catheterization in a one-month old female infant. In spite of spontaneous thrombosis, the patient's course was uneventful. During the five-year follow-up period no further complications developed and operation was not required. Aneurysms of the aorta are rare in the very young and the infrarenal location is rarer. Sixteen other cases published in the literature are reviewed. Etiologic considerations and therapeutic modalities are discussed.

Sequential development of multiple aortic aneurysms in a neonate post umbilical arterial catheter insertion

A neonate in whom multiple aortic aneurysms developed as a result of umbilical arterial catheterization is presented. Initially a single aneurysm was diagnosed by ultrasound. Serial sonographic examinations showed enlargement of the first as well as formation and subsequent enlargement of additional aneurysms.

Candida: an increasingly important pathogen in the nursery

Advances in neonatal care now permit the survival of very immature infants. Although candidiasis is not a new disease, the spectrum of clinical disease has greatly widened and the rate of invasive disease has increased significantly. This article reviews the history, microbiology, and epidemiology of candidal infections, both superficial and invasive. Particular attention is paid to the pathogenesis of and risk factors associated with the development of invasive disease, as well as its clinical manifestations, diagnosis, and treatment.

Aneurysm of the abdominal aorta in an eighteen-month-old child

We report the case of an infected aneurysm of the abdominal aorta in a 18 month-old child, discovered by routine palpation of the abdomen during hospitalization for pneumonia. Ultrasonography and arteriography showed a 6 cm aneurysm of the abdominal aorta beginning distal to the renal arteries which occluded the right common iliac artery. The aneurysm was treated by interposing a 6 mm Gore-Tex graft between the infrarenal aorta and the aortic bifurcation. Pathologic examination of the aneurysmal wall demonstrated a leukocytic infiltrate and the presence of encapsulated Gram positive organisms. Arterial aneurysms are exceedingly rare in children. Their etiology is varied: infection, connective tissue disease, trauma, inflammatory arterial disease or other rare diseases such as tuberous sclerosis, neurofibromatosis, or Behçet's disease.

Aortic thrombosis diagnosed by ultrasound

A neonate developed aortic thrombosis following catheterization of the umbilical artery. The thrombus was identified and followed up by ultrasonography. Fibrinolytic therapy led to the almost complete disappearance of the aortic thrombus but the child died of cerebral haemorrhage. Physicians should be alerted to the possibility of aortic thrombosis in neonates following umbilical arterial catheterization. Ultrasonography is an appropriate method for diagnosis and follow-up in these cases.