Vessel Perforation and False Tracking Resulting From Umbilical Artery Catheterization

Introduction

Umbilical artery catheterization (UAC) was first reported in 1962. ¹ Over the past 50 years, invasive monitoring has become an integral aspect of the management of critically sick neonates. The additional information accrued through the use of umbilical artery catheters is often very helpful and necessary but has the potentially significant complications: infection, vascular perforation, coarctation, dissection, thrombosis, and aneurysmal degeneration of the aorta and its major branches, blanching or cyanosis of part or all of a distal extremity or the buttock area resulting from either vasospasm or a thrombotic or embolic incidence, ischemic necrosis of the gluteal region, necrotizing enterocolitis, bladder rupture, urinary ascites, and peroneal nerve palsy paraplegia.^2,3 The overall rate of complication of UAC placement is approximately 10%. ³ Miller et al. ⁴ reported 7/400 (1.75%) newborns with umbilical or hypogastric artery perforation following UAC, all infants had massive extra- and intraperitoneal bleeding. Here we report the first case of umbilical artery perforation with false tracking alongside the hypogastric artery and subsequent entry into the internal iliac artery. The complication did not cause hemorrhage or a life-threatening event.

Case Report

A 675-g second-born twin male was born at 24 weeks’ gestation to a 17-year-old primigravida who delivered vaginally with the assistance of the emergency room (ER) physicians at an outside hospital. Apgar scores were 5 and 7 at 1 and 5 minutes, respectively. The pregnancy was significant for the absence of prenatal care and unknown group B Streptococcus culture status. The medical history was reported to be unremarkable otherwise. Physical examination revealed a weight of 675 (50th centile, length 31 cm (35th centile), head circumference 23 cm (75th centile). No anomalies were noted. The baby had respiratory distress at birth, required intubation and surfactant administration, which was done by our transport team that had reached just as the infant was being delivered. The infant was subsequently transferred on a conventional transport ventilator to our institution.

Upon arrival at our institution, the patient was found to be requiring 100% oxygen to maintain satisfactory arterial oxygenation. He was placed on high-frequency oscillatory ventilation, and a 3.5-Fr (Argyle-Polyurethane single lumen) umbilical catheter was inserted into the left umbilical artery for blood sampling purposes. Blood pressure monitoring and blood sampling was commenced via the umbilical catheter without any difficulty when the infant was 4 h old. A radiograph, which was performed soon after line placement, showed normal positioning of the catheter, and the tip of the catheter was at a level between the seventh and eight thoracic vertebrae (Figure 1). The catheter was continuously infused with heparinized solution. Blood pressure monitoring and blood sampling were commenced via the umbilical artery catheter. The mean arterial blood pressure values obtained from the transducer connected to the umbilical catheter were about 25–30 mm Hg. Laboratory evaluation of a blood sample collected from the umbilical catheter revealed a peripheral white blood cell count of 10.6 ×10⁹/L, blood hemoglobin of 10.4 g/dL, Hct of 32.3%, and platelet count of 163,000/mm³. Initial blood glucose levels were 110–250 mg/dL. Although intravenous antibiotic therapy with ampicillin and gentamicin had been started within the first hour after the infant’s birth, he succumbed to overwhelming sepsis at 16 h of age. Blood cultures grew group B Streptococcus (GBS). The 545-g co-twin also died from GBS septicemia at 24 h of age

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Figure 1.

a–b, Radiograph anteroposetrior and lateral views showed the catheter was in expected position making a gentle curve inferiorly with the tip ascending anterior to the spine and positioned at thoracic vertebrae 7–8.

Autopsy Findings

External examination was unremarkable. There was no ecchymosis of the periumbilical and lower abdominal wall. Internal examination revealed umbilical artery perforation at the level of the base of the urinary bladder, and after false tracking, the catheter had entered the proximal internal iliac artery (Figures 2 to 4). There was no blood clot or hematoma in the lower abdominal peritoneum. The left iliac artery contained the umbilical catheter, and the tip of the catheter was in the aorta. Examination of the placental confirmed a 3-vessel umbilical cord (Figure 5).

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Figure 2.

Umbilical artery with a catheter at the base of the umbilicus.

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Figure 3.

Umbilical catheter perforation occurred at umbilical artery near the base of the urinary bladder (B), the catheter exited retroperitoneally and re-entered into the left internal iliac artery.

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Figure 4.

Catheter perforation occurred at the left umbilical artery (arrow) and re-entry into the left internal iliac artery (arrow).

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Figure 5.

Three-vessel umbilical cord.

Discussion

Umbilical artery catheters are an essential aid in the management of acutely ill newborn infants. UAC use occurs in 10.8%–64.4% of neonatal intensive care unit admissions, and 2% of all births. ⁵ The most common complication is a thrombotic phenomenon. Postmortem and aortographic examinations of infants undergoing UAC placement report that the incidence of complications is 16%–26%. ⁶ Perforation of the umbilical artery has been described and fatal hemorrhage is rare but has been reported. ⁴ Difficulty with catheter insertion may occur at 2–3 cm below the anterior abdominal wall or at the confluence of the umbilical and hypogastric artery due to endothelial cushions causing maximal luminal narrowing at these sites.^7–9 The abrupt change in the course of the umbilical artery at these sites makes them susceptible to perforation. ⁹ In our patient, the perforation was at the confluence of the umbilical and hypogastric artery.

Most of the reported case with perforations had traumatic (insertion against resistance) and multiple attempts at UAC placement. Most were in preterm infants (27–34 weeks of gestation) with high fatality rates.^4,10

Restricted indications for catheter use, routine roentgenographic confirmation of catheter track and tip location, close observation and monitoring, avoidance of catheter manipulation, awareness of this rare and fatal complication, and vigilance to remove catheters when no longer required are said to reduce the incidence of the iatrogenic neonatal complications.

The complication of umbilical artery catheterization in our case has not been previously reported. Our case is the first in literature where the catheter perforated the umbilical artery and re-entered into the internal iliac artery. The catheter was found in the iliac artery and the aorta at autopsy. There was no blood clot or hemorrhage from the complication. It is possible that the patient was in a state of septic shock and the blood pressure was too low to cause hemorrhage at the perforated site. Since the patient succumbed to GBS septicemia at 16 h of life and his twin at 24 h, the course of the umbilical artery catheter complication is unknown.

We reviewed the literature on umbilical vessel anomalies in order to find an explanation for the autopsy findings in our patient. We found one case report of a baby with 3 umbilical arteries (4-vessel umbilical cord). ¹¹ Our patient had a 3-vessel umbilical cord. There is one report of a postmortem finding: a preterm infant with umbilical artery perforation, the catheter reentered the aorta. ¹⁰

In summary we report an extremely low-birth-weight neonate with umbilical artery perforation and false tracking along the hypogastric artery after umbilical artery catheterization. The catheter re-entered the internal iliac artery and was found to be dwelling in the aorta and functioning appropriately. This complication is hence very unique.