Evaluation of Umbilical Catheter and Tube m Premature Infants

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1 ,: :... Evaluation of Umbilical Catheter and Tube m Premature Infants Lakshmana Das Narla, MD Mark Horn, MD GaryK Lofland, MD Williarn B. Moskowitz, MD Umbilical arterial and venous catheters, endotracheal tubes, and nasogastric tubes are routinely used in treating premature infants, and radiologists play a critical role in evaluating proper catheter and tube placement and recognizing potential complications. Ideally, an umbilical venous catheter should be positioned in the right atrium; an umbilical arterial catheter, between T-6 and T-1O (high position) or between L-3 and L-5 (low position); an endotracheal tube, 1.5 cm above the carina, with the infant s head in a neutral position; and a nasogastric tube, in the body of the stomach. Catheters and tubes can be malpositioned in a variety ofvessels and the main stem bronchi, respectively. Complications include extraluminal placement of catheters (which can result in death), thrombi in the aorta and pulmonary artery, aortic aneurysm, subglottic stenosis, intubation granuloma, and perforation of the esophagus and stomach. U INTRODUCTION Since the introduction of intravascular catheters and the use of the umbilical vein for exchange transfusions by Diamond in 1947 (1), umbilical arterial and venous catheters have been routinely used in premature infants to administer parentenal alimentation or antibiotics for various disorders (eg, necrotizing enterocolitis, osteomyehitis). Thus, proper placement of these catheters, as well as of endotracheal and nasogastric tubes, constitutes an integral part in the management ofpremature infants. Radiologists play a critical role in evaluating placement of the catheters and tubes and recognizing potential complications resulting from their use. The purpose of this article is to show the ideal position of umbilical arterial and venous catheters, endotracheal tubes, and nasogastric tubes. We review the normal Index terms: Catheters and catheterization, in infants and children, , #{149} Infants, newborn, cardiovascular system RadloGraphics 1991; 11: I From the Departments ofradiology (LD., M.H.), Cardiothoracic Surgery (G.K.L), and Cardiology (W.B.M.), Medical College ofvirginia, virginia Commonwealth University, 12th and Marshall sts, Box 615, MCI Station, Richmond, VA From the 1990 RSNA scientific assembly. Received March 1, 1991; revision requested April 11 and received June 3; acceptedjune 10. Address reprint requests to L.D. C RSNA,

2 1. 2. Figures 1, 2. Schematics depict the prenatal (1) and postnatal (2) anatomy of the circulatory system in the chest. DV = ductus venosus, FO = foramen ovale, IN = hepatic vein, P/C = inferior vena cava, LA = left atrium, LGT = higamentum teres hepatis, LGV = higamentum venosum, MUL = medial umbilical ligament, Pm, = portal vein, R4 = right atrium, WA = superior vesical artery, UA = umbilical artery, UV = umbilical vein. anatomy of the circulatory system before and after birth, describe the appearance of conrectly positioned catheters and tubes on radiographs, and present examples of malpositioned catheters and tubes and possible complications. U NORMAL CIRCULATORY SYSTEM. Prenatal Anatomy The right umbilical vein disappears by 6 weeks gestational age. The left umbilical vein passes upward along the free margin of the falciform ligament (Fig 1). At the porta hepatis, it divides into two branches. The larger is joined by the portal vein, and the smaller branch continues cranially as the ductus venosus. The ductus venosus is 1-2 cm long and ends in the left or middle hepatic vein, very chose to the junction with the inferior vena cava. Blood entering the right atrium is directed toward the foramen ovale by the valve of the inferior vena cava. The lower bonder of the septum secundum deflects the flow into two unequal streams. The lesser flow mixes with the venous return from the superior vena cava 850 U RadioGraphics U Das Narla et a! Volume 1 1 Number 5

3 a. b. Figure 3. (a) Axial computed tomographic (CT) scan obtained at the level ofthe femoral heads shows the medial umbilical ligament (arrow), formed from the obliterated umbilical artery. (Courtesy ofjames W. Walsh, MD, University of Minnesota, Minneapolis.) (b) Axial CT scan shows the medial umbilical ligament (arrow), formed from the obliterated urachus. and passes through the right ventricle, from where it passes to the pulmonary artery, ductus arteniosus, and descending aorta and returns to the placenta through the umbilical artery. Little blood passes to the lungs because of the high pulmonary vascular resistance. The main or larger stream passes through the foramen ovale to the left atrium, mixes with any blood returning from the lungs, and enters the heft ventricle. The blood passes through the ascending aorta to the head, neck, and upper limbs.. Postnatal Anatomy The proximal portion of the umbilical artery remains patent and branches into the supenor vesical arteries (Fig 2). The distal part of the umbilical artery extends from the sides of the bladder to the umbilicus. The artery, along with the urachus, becomes obliterated between the 2nd and 5th days after birth, and they persist as fibrous cords covered with peritoneum, the medial umbilical ligaments (Fig 3). The umbilical vein forms the ligamentum teres hepatis in the lower margin of the falciform ligament. The ductus venosus forms the ligamentum venosus of the liver, and the ductus arteriosus forms the ligamentum arteniosum, which connects the left pulmonary artery to the arch of the aorta. Increasing pressure in the left atrium presses the septum primum against the septum secundum and closes the foramen ovale. The major aortic branches arise at the following vertebra! levels (even though there is considerable variation) : the celiac trunk at T-12, the superior mesenteric artery at T-12 to L-1, the renal artery at L-1 to L-2, the inferior mesenteric artery at L-3, and the aortic bifurcation at L-4. September 1991 Das Narla et a! U RadioGraphics U 851

4 Figure 4. (a) Radiograph of the lower chest and abdomen shows an umbilical venous catheter (black arrows), with its tip in the right atrium, and an umbihical arterial catheter (white arrow) at the T-6 vertebral body level. 0)) Abdominal radiograph of another patient shows an umbilical arterial catheter below the L-3 vertebral body level. (c) Lateral radiograph of the abdomen in another patient shows two umbilical venous catheters proximally located in the umbilical vein. C. 852 U RadioGrapbics U Das Narla et a! Volume 1 1 Number 5

5 a. b. Figure 5. (a) Coronal US image of the upper abdomen shows an umbilical arterial catheter (arrowhead), the origins of the celiac axis (white arrow), and the superior mesenteric artery (black arrow). (b) Sonogram (the subcostal four-chamber view) shows an umbilical venous catheter (arrow) in the right atrium. U PLACEMENT OF CATHETERS AND TUBES. Umbilical Venous and Arterial Catheters The idea! position of an umbilical venous catheter is in the right atrium (Fig 4). The umbilical venous catheter is passed through the umbilicus, umbilical vein, left portal vein, ductus venosus, middle or left hepatic vein, and inferior vena cava and into the right atrium. As seen on frontal radiographs, the venous catheter runs cephalad to enter the liver. On the anteroposterior view, the catheter curves gently to the right within the liver (Fig 4a). On the lateral view, the catheter is seen anteriorly traversing the liver, and it assumes an S-shaped curve before reaching the heart. Umbilical arterial catheters are placed at one of the two sites away from the major yessd orifices in the aorta (2). A high position is between T-6 and T-10 (Fig 4a); low catheters are ideally positioned between L-3 and L-5 (Fig 4b). The umbilical arterial catheter is passed through the umbilicus, umbilical artery, internal iliac artery, and common iliac artery and into the aorta. As seen on frontal radiographs, the arterial catheter dips into the pcivis before joining the internal iliac arteries (Fig 4a). On the lateral view, the catheter is seen posteriorly in front of the spine and in the aorta. At times, a second catheter can be placed in the umbilical vein to avoid cannulating the umbilical artery (Fig 4c). Real-time ultrasound (US) has been used to locate umbilical venous and arterial catheters because it allows direct visualization of pertinent vascular anatomy (3). Catheters appear as well-defined, parallel, linear echogenic structures within the vascular lumen (Fig 5). US is also useful in the assessment of comphications, such as thrombosis and aortic aneurysm, following umbilical arterial cathetenization (4). September 1991 Das Narla et a! U RadioGrapbic.s U 853

6 Figures 6, 7. (6) Radiograph of the chest, with the infant s chin turned to the side, shows an endotracheal tube above the carmna (arrow). If the infant flexes its chin, the tube position becomes low and suboptimal. (7) Frontal (a) and lateral (b) views of the chest in another infant demonstrate the normal course of nasogastnic tube through the esophagus into the stomach. 6.. Endotracheal and Nasogastric Tubes The optimal position for an endotracheal tube is 1.5 cm above the carmna, with the patient s head held in a neutral position. Marked changes in endotracheal tube position occur with head movement (5). The tube will move caudad with flexion, cephalad with extension, and cephalad with lateral rotation of the head 854 U RadioGrapbics U Das Narla et a! Volume 1 1 Number 5

7 Figures 8-i 1. Frontal radiographs of four patients show an umbilical venous catheter in the superior mesentenic vein (8), in the left upper quadrant in the splenic vein (arrow in 9), in the superior vena cava (arrow in 10), and in the right internal jugular vein (arrow in 11). and neck, according to the lever arm and fulcrum principle. Chest radiographs obtained for evaluation of endotracheal tube placement should include the mandible in order to assess tube position accurately (Fig 6). Nasogastric tubes are placed in the body of the stomach to decompress the stomach in infants being treated for necrotizing enterocolitis (Fig 7). Duodenal tubes are frequently used for feeding, and the ideal location is approximately 1 cm proximal to the duodenojejunal junction (ligament of Trietz). U MALPOSITIONING AND COMPLICATIONS OF CATHETERS AND TUBES. Umbilical Venous and Arterial Catheters Umbilical venous and arterial catheters can be malpositioned in various vascular structures. An umbilical venous catheter can enter the superior mesentenc vein, splenic vein, supenor vena cava, and internal jugular vein (Figs 8-1 1). A venous catheter can also enter the September 1991 Das Narla et a! U RadioGrapbic.s U 855

8 Figure 12. (a) Frontal radiograph demonstrates an umbilical venous catheter in the left atrium. (b) Lateral view shows the catheter in the left atrium entering through the foramen ovale. left atrium through a patent foramen ovale (Fig 12), an anomaly found in 27% of premature infants (6). An umbilical arterial catheter may be ma!- positioned in the subclavian artery, cehiac axis, inferior gluteal artery, and renal artery (Figs 13-16). 856 U RadioGraphics U Das Narla et a! Volume 1 1 Number 5

9 Figures (13) Frontal radiograph shows an umbilical arterial catheter in the right subclavian artery. (14) Frontal radiograph ofanother infant shows an umbilical arterial catheter (arrow) in the cehiac axis. (15) Frontal (a) and lateral (b) views of the abdomen and pelvis of another infant show an umbilical arterial catheter in the inferior gluteal antery. (16) Frontal view ofanother infant shows an umbilical arterial catheter in the right renal artery. 16. September 1991 Das Narla et a! U RadioGraphics U 857

10 Figures (17) Frontal (a) and lateral (b) radiographs ofthe abdomen show an umbilical venous catheter in an extrahuminal location (arrow). (18) Frontal radiograph ofanother infant obtained after contrast material was injected into an umbilical venous catheter shows opacification of the left atrium and cxtravasation ofcontrast material (arrow) into the pericardium and pleural space. The penicardium sealed spontaneously without surgical intervention. (19) Frontal radiograph ofanother patient reveals a fragmented umbilical venous catheter in the liver. Follow-up images showed no migration of the catheter, and the patient was asymptomatic. Both umbilical venous and arterial catheters may be placed in an extraluminal location (Fig 17), occasionally resulting in death of the infant. An umbilical venous catheter that entens the left atrium through a patent foramen ovale can perforate the pericardium and pleural space (Fig 18). A venous catheter can fragment in the liver (Fig 19). 858 U RadioGraphics U Das Narla et a! Volume 1 1 Number 5

11 . iiji_ - I_ Figures 20, 21. (20) Coronal sonogram shows echogenic thrombus (arrow) extending below the renal artery to the bifurcation ofthe aorta. (21) Coronal sonogram ofanother patient shows a fusiform aneurysm ofthe abdominal aorta (arrows) below the renal artery. (Courtesy ofjaime Tisnado, MD, Medical College of Virginia, Richmond.) a. b. Figure 22. Echocardiograms of an infant born at 27 weeks gestation and who was receiving total parenteral nutrition via a central line. (a) Subcostal four-chamber twodimensional echocardiogram shows a thrombus (arrow) in the right atrium attached to the atrial septum above the tricuspid valve. (b) Parasternal short-axis view shows the thrombus (arrow) extending through the valve into the right yentricle and compromising the right main pulmonary artery. The thrombus was excised and proved to be calcified. Thromboembolic sequelae of catheterization with umbilical venous and arterial catheters in neonates have been well documented (7-9). Asymptomatic thrombus formation in association with intraaortic catheter is commonly observed with both angiography (10) and sonography (Fig 20). In the majority of cases, clots are self-limiting. Occasionally, they become infected and cause septic embohi or a mycotic aneurysm (Fig 21). They may also be calcified and require surgery for removal (Fig 22). September 1991 Das Narla et a! U RadioGrapbic.s U 859

12 .. Figures 23, 24. (23) Arteriograms ofa premature infant who was receiving antibiotics via an umbilical venous catheter and who developed a thmombus. (a) Arteriogram shows a thrombus (open arrow) at the junction of the internal jugular vein and brachiocephalic vein, with retrograde filling of extradural sinuses (solid arrow). (b) Arteriogram obtained after fibrinolytic therapy shows contrast material entering the right atrium and no retrograde filling of extradui-al sinuses, findings indicating the thrombus had decreased in size. (24) Frontal radiograph of another patient demonstrates extravasation of contrast material from the internal juguhar central line into soft tissue. At times, fibrinolytic therapy may help resolve clots at the ends of umbilical venous and arterial catheters (Fig 23). Catheters can fragment or break, resulting in complications such as extravasation of contrast material into the soft tissues (Fig 24). 860 U RadioGrapbics U Das Narla et a! Volume 1 1 Number 5

13 Figures (25) Frontal radiograph reveals an endotracheal tube directed into the right main stem bronchus, resulting in complete volume loss in the left lung and right upper lobe. (26) Frontal view of the neck of another patient shows subglottic stenosis (arrows) secondary to endotracheal intubation. (27) Lateral view ofthe neck ofanother patient shows a circular radiopaque area (arrow) in the trachea. Granuioma was removed at endoscopy Endotracheal and Nasogastric Tubes Endotracheal tubes can be placed too far into either the right or left main stem bronchus (Fig 25). Prolonged endotracheal intubation can lead to complications, one ofwhich is acquired subglottic stenosis (Fig 26). Approximately 5% of the neonates who undergo intubation for respiratory distress syndrome are reported to develop chronic subglottic stenosis (1 1). Mechanical, chemical, and bacterial irritation of the mucosa play a role in the development of subglottic stenosis. Another known complication of prolonged endotracheal intubation is granuloma formation (Fig 27) (12). September 1991 Das Narla et a! U RadioGraphics U 861

14 Figures 28, 29. (28) Frontal (a) and lateral (b) radiographs demonstrate a nasogastric tube in the left lower lobe. It is very important to confirm the location of a nasogastric tube before feeding is started. (29) Frontal view of another patient shows a nasogastric tube in the region of the left main stem bronchus. Opacity in the left lung base represents formuha, which was instilled through the tube without confirmation of its position. Nasogastric tubes can be malpositioned in the lung (Fig 28) or in the left main stem bronchus (Fig 29). These tubes can perforate the stomach (Fig 30) and the esophagus (Fig 31). U CONCLUSION Successful outcome for premature infants depends greatly on proper placement and monitoning of umbilical arterial and venous catheters, endotracheal tubes, and nasogastnic tubes. Optimal placement is critical, and ma!- position can lead to many complications and occasionally death. Plain radiography, US, and angiography are used to evaluate these catheters and tubes and the complications resulting from their use. U REFERENCES 1. Diamond LK. Erythroblastosis foetahis or haemolytic disease of newborn. Proc Roy Soc Med 1947; 40: Baker DH, Berdon WE, James SL. Proper localization of umbilical arterial and venous catheters by lateral roentgenograms. Pediattics 1969; 43: Oppenheimer DA, Carroll BA, Garth KE, Parker BR. Sonographic localization of neonatal umbilical catheters. AJR 1982; 138: Oppenheimer DA, Carroll BA, Garth K. Ultrasonic detection of complications following umbilical catheterization in the neonate. Radiology 1982; 145: U RadioGraphics U Das Narla et a! Volume 11 Number 5

15 30b. Figures 30, 31. (30a) Radiograph ofthe abdomen obtained with the patient supine shows a nasogastric tube over the left lower abdomen. (30b) Radio- - graph of the abdomen obtained with the patient in the heft lateral decubitus position shows posterior location of the tube and free air (arrow). At surgery, perforation was found along the greater curvature ofthe stomach. (31) Frontal radiograph of another infant demonstrates the nasogastric tube overlying the right upper quadrant, instead of coursing toward the left upper quadrant. Perforation spontaneoushy sealed, and the infant recovered without any complications. 31. I 5. Donn SM, Kuhns LR. Mechanism of endotracheal tube movement with change of head position in the neonate. Pediatr Radiol 1980; 9: Hagen PT, Scholz DG, Edwards WD. mcidence and size of patent foramen ovale during first ten decades of life: an autopsy of 965 normal hearts. Mayo Clin Proc; 1984; 59: Tooley WH. What is the risk ofan umbilical artery catheter. Pediatrics 1972; 50: Tyson JE, Desa DJ, Moore S. Thromboatheromatous complications of umbilical arterial catheterization in the newborn period: clinicopathological study. Arch Dis Child 1976; 51: Wigger HJ, Bransihver BR, Blanc WA. Thromboses due to catheterization in infants and chihdren.j Pediatr 1970; 76: Neal WA, Reynolds JW, Jarvis CM, et al. Umbihical artery catheterization: demonstration of arterial thrombosis by aortography. Pediattics 1972; 50: Marshak G, Grundfast KM. Subglottic stenosis. Pediatr Chin North Am 1981; 28: Balestnieni F, Watson CB. Intubation granuloma. Otolaryngol Clin North Am 1982; 15: September 1991 Das Narla et a! U Ra4ioGrapbics U 863