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A 55-year-old man with end-stage renal disease had severe left ventricular dysfunction and a history of deep vein thrombosis. He underwent renal transplantation, during which a central venous catheter was inserted into the right jugular vein. The central venous pressure (CVP) exceeded 20 mmHg throughout the operation but there was no other adverse event. After surgery, although the left ventricular dysfunction improved, the CVP remained high. On postoperative day 10, the patient presented with cyanosis of the arms and redness of the face and was diagnosed with superior vena cava (SVC) syndrome, for which he underwent emergency thrombectomy and SVC reconstruction. The clinical course of this patient suggests that his end-stage renal disease-associated hypercoagulable state may have promoted thrombus formation. Moreover, placing the central venous catheter tip too deep may have encouraged thrombus formation. Repositioning the tip may have prevented this complication.

Introduction

Advanced hemodynamic monitoring using transpulmonary thermodilution (TPTD) is established for measurement of cardiac index (CI), global end-diastolic volume index (GEDVI) and extra-vascular lung water index (EVLWI). TPTD requires indicator injection via a central venous catheter (usually placed via the jugular or subclavian vein). However, superior vena cava access is often not feasible due to the clinical situation. This study investigates the conformity of TPTD using femoral access.

Methods

This prospective study involved an 18-month trial at a medical intensive care unit at a university hospital. Twenty-four patients with both a superior and an inferior vena cava catheter at the same time were enrolled in the study.

Results

TPTD-variables were calculated from TPTD curves after injection of the indicator bolus via jugular access (TPTDjug) and femoral access (TPTDfem). GEDVIfem and GEDVIjug were significantly correlated (rm = 0.88; P < 0.001), but significantly different (1,034 ± 275 vs. 793 ± 180 mL/m2; P < 0.001). Bland-Altman analysis demonstrated a bias of +241 mL/m2 (limits of agreement: -9 and +491 mL/m2). GEDVIfem, CIfem and ideal body weight were independently associated with the bias (GEDVIfem-GEDVIjug). A correction formula of GEDVIjug after femoral TPTD, was calculated. EVLWIfem and EVLWIjug were significantly correlated (rm = 0.93; P < 0.001). Bland-Altman analysis revealed a bias of +0.83 mL/kg (limits of agreement: -2.61 and +4.28 mL/kg). Furthermore, CIfem and CIjug were significantly correlated (rm = 0.95; P < 0.001). Bland-Altman analysis demonstrated a bias of +0.29 L/min/m2 (limits of agreement -0.40 and +0.97 L/min/m2; percentage-error 16%).

Conclusions

TPTD after femoral injection of the thermo-bolus provides precise data on GEDVI with a high correlation, but a self-evident significant bias related to the augmented TPTD-volume. After correction of GEDVIfem using a correction formula, GEDVIfem shows high predictive capabilities for GEDVIjug. Regarding CI and EVLWI, accurate TPTD-data is obtained using femoral access.

Background

Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure.

Methods

Catheters for pressure measurement were inserted into the stomach, urinary bladder, peritoneal cavity, pulmonary artery and inferior vena cava of 12 pigs. The pressures were recorded simultaneously at baseline, during 10 cm H20 PEEP, external abdominal pressure (7 kg weight) plus PEEP, external abdominal pressure without PEEP, and again under baseline conditions.

Results (mean ± SD)

PEEP alone increased diastolic pulmonary artery and inferior vena cava pressure but had no effect on the other pressures. PEEP and external abdominal pressure increased intraperitoneal pressure from 6 ± 1 mm Hg to 9 ± 2 mm Hg, urinary bladder pressure from 6 ± 2 mm Hg to 11 ± 2 mm Hg (p = 0.012), intragastric pressure from 6 ± 2 mm Hg to 11 ± 2 mm Hg (all p ≤ 0.001), and inferior vena cava pressure from 11 ± 4 mm Hg to 15 ± 4 mm Hg (p = 0.01). Removing PEEP and maintaining extraabdominal pressure was associated with a decrease in pulmonary artery diastolic but not in any of the other pressures. There was a significant correlation among all pressures. Bias (-1 mm Hg) and limits of agreement (3 to -5 mm Hg) were similar for the comparisons of absolute intraperitoneal pressure with intra-gastric and urinary bladder pressure, but larger for the comparison between intraperitoneal and inferior vena cava pressure (-5, 0 to -11 mm Hg). Bias (0 to -1 mm Hg) and limits of agreement (3 to -4 mm Hg) for pressure changes were similar for all comparisons

Conclusions

Our data suggest that pressure changes induced by external abdominal pressure were not modified by changing PEEP between 0 and 10 cm H20.

Purpose

To investigate the reliability of intra-atrial electrocardiogram (ECG) use for external jugular vein (EJV) catheterization.

Materials and Methods

Patients undergoing open heart surgery in Suleyman Demirel University Hospital between February and June 2006 were included in the study. Using a sterile Seldinger technique, a triple lumen polyurethane central venous catheter was introduced (Certofix® Trio V 720, length 20 cm, 7 French) under intra-atrial ECG guidance. The presence of an increase in P-wave size was recorded. Just after the surgery, a portable chest X-ray was taken. The method was considered to be successful when a change in P-wave could be seen and the catheter was in the superior vena cava, as well as when there was no change in P-wave and the catheter was not in the superior vena cava.

Results

In six patients (12%), we were not able to advance the guidewire. In the remaining 44 patients, the catheter was inserted without problem. Eight of these 44 catheters were positioned in the innominate vein, with a malposition ratio of 18%. The success rate of external jugular vein cannulation with intra-atrial ECG was 95%. No complications occured related to the EJV cannulation.

Conclusion

Considering that it is easily accessed without complication, and the malposition is successfully detected by intra-atrial ECG, EJV is a suitable access for central venous cannulation when internal jugular vein (IJV) is not usable.

Background

Chest X-ray is routinely performed to check the position of the central venous catheter (CVC) inserted through the internal jugular or subclavian vein, while the further evaluation of CVC malfunction is usually performed by contrast venography. In patients with superior vena cava obstruction, the tip of the catheter is often seen in collateral mediastinal venous pathways, rather than in the superior vena cava. In such cases detailed knowledge of thoracic vessel anatomy is necessary to identify the exact location of the catheter.

Case report.

We report a case of 32-year-old female patient with relapsing mediastinal lymphoma and previous superior vena cava obstruction with collateral azygos-hemiazygos venous pathways. The patient had CVC inserted through the left subclavian vein and its position was detected by CT to be in the dilated left superior intercostal vein and accessory hemiazygos vein. Considering that dilated accessory hemiazygos vein can tolerate infusion, the CVC was left in place and the patient had no complaints related to CVC (mal)position. Furthermore, we present anatomical and radiological observations on the azygos-hemiazygos venous system with the special emphasis on the left superior intercostal vein.

Conclusions

Non-contrast CT scans can be a valuable imaging tool in the detection of the CVC position, especially in patients with renal insufficiency and contrast media hypersensitivity.

Stenting of the central veins is well established for treating localized venous stenosis. The techniques regarding catheter preservation for central venous catheters in the superior vena cava have been described. We describe here a method for stent implantation in the superior vena cava and the left brachiocephalic vein, and principally via a single jugular venous puncture, while saving a left sided jugular central venous catheter in a patient suffering from central venous stenosis of the superior vena cava and the left brachiocephalic vein.

Introduction

Superior vena cava (SVC) obstruction secondary to central venous catheterization is an increasingly recognized complication.

Case presentation

We present two cases of superior vena cava obstruction secondary to indwelling central venous catheters used for haemodialysis access. One of the patients developed the unusual complications of torrential epistaxis and haemoptysis, which has been reported only once so far in the literature. The other patient developed melaena secondary to downhill oesophageal varices. We briefly discuss the pathophysiology, symptoms and signs, investigations and management of superior vena cava obstruction and thrombosis.

Conclusion

Increasing use of central venous access for haemodialysis will increase the incidence of central venous stenosis, thrombosis and exhaustion. Superior vena cava obstruction is likely to be an increasingly recognised complication of vascular access in the future.

Thrombosis involving a permanent infusion catheter in the subclavian vein and superior vena cava is relatively common, especially in cancer patients. Edema of the arms and head is a well-known clinical consequence of this thrombosis, with an intrinsic risk of pulmonary embolism; however, systemic embolization into the cerebral circulation has not been reported as a sequela. Herein, we describe the case of a 56-year-old man with metastatic prostate cancer who developed superior vena cava syndrome due to extensive thrombosis in the presence of a central venous catheter that was used for long-term chemotherapy. The patient's case was complicated by a cerebrovascular accident that was most likely caused by a paradoxical air embolism. A clear mechanism for the embolism was provided by a network of collateral veins, which developed between the brachiocephalic vein and the left atrium due to the superior vena cava obstruction and resulted in a right-to-left shunt. We discuss diagnosis and treatment of the condition in our patient and in general terms.

Introduction

A persistent left superior vena cava is found in 0.3–0.5% of the general population and in up to 10% of patients with a congenital cardiac anomaly. It is the most common thoracic venous anomaly and is usually asymptomatic. Being familiar with such anomaly could help clinicians avoid complications during placement of central lines, Swan-Ganz catheters, PICC lines, dialysis catheters, defibrillators, and pacemakers.

Case Presentation

We describe a case of persistent left superior vena cava that was noted after placement of a central line. Mr JJ is a 41 year old African American man who was hospitalized for evaluation and management of alcoholic necrotizing pancreatitis. He required multiple central lines placements. He was noted to have a persistent left superior vena cava that was not recognized initially and thus lead to an unnecessary extra central line placement.

Discussion

This anatomic variant may pose iatrogenic risks if it is not recognized by the clinician. A central catheter that tracks down the left mediastinal border may also be in the descending aorta, internal thoracic vein, superior intercostal vein, pericardiophrenic vein, pleura, pericardium, or mediastinum.

Conclusion

Our case is significant because the patient had two extra central venous catheter placements. This case strongly demonstrates the importance of knowing the thoracic venous anomalies.

Differential vascular remodeling is one of the major mechanisms of heterogeneity in atherosclerosis. The structural and functional heterogeneity between arteries and veins determines the degree of vascular remodeling. Matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) play key roles in vascular structural and functional remodeling. We hypothesized that the level of blood flow in different arteries and veins caused structural and functional heterogeneity that ultimately determined potential vascular remodeling. To test this hypothesis, in vivo blood flow and blood pressure in the aorta, carotid, femoral artery, and femoral vein was measured in male Sprague-Dawley rats (weight 380–400 gm). Arterial and venous pressures were measured by PE-50 catheter cannulation. Blood flow was measured by a transonic ultrasound system. The aortic arch, femoral and carotid arteries, and abdominal vena cava were isolated to determine the expression of MMP-2, -9, -12, and -13 and TIMP-1, -3, and -4 by Western blot and in gelatin gel zymography. Masson trichrome and van Gieson stains were used to stain the histologic tissue sections. The results revealed that blood flow was higher in the aorta and carotid artery than the femoral artery and vein. MMP-9 and MMP-13 were higher in the carotid artery in comparison with the other blood vessels, while TIMP-3 showed higher expression in the aorta than the arteries. Further, the MMP-9 activity was significantly higher in the carotid artery than in the aorta and femoral artery. There was a higher degree of basement membrane collagen in the femoral artery and therefore a low elastin: collagen ratio, while in the carotid artery a higher level of elastin and, therefore, a high elastin: collagen ratio was found. The results suggested that medial thickness and elastin:collagen ratios had a threshold in blood flow in the range 0.6–2.5 mL/min, which increased robustly if blood flow increased to 2.7 mL/min. This pattern was inverted by the total MMP:TIMP ratio. We conclude that vascular remodeling is a function of rate of blood flow, which would in turn be determined by the amounts of MMPs and their inhibitors present. The study combined the endothelial and dynamic (blood flow/pressure) components that affect medial thickness and elastin: collagen ratios.

Superior vena cava syndrome (SVCS) is usually caused by a malignancy or the presence of an intravascular device in a central vein. A 74-year-old male with a history of a superior vena cava (SVC) stent underwent embolisation of a brain arterio-venous malformation through the right meningeal artery with liquid Onyx. Two weeks later he presented with acute respiratory failure, upper airway obstruction, plethora, varices of the chest wall and stridor. He was intubated and placed on mechanical ventilatory support. Chest imaging revealed a linear structure in the SVC, extending to the right atrium. Interventional radiology removed the material, which was determined to be liquid Onyx. Venous pressures of the right internal jugular vein decreased after removal of the material. The symptoms resolved and patient was successfully extubated. This is the first reported case of SVCS caused by liquid Onyx.

Introduction

Pacemaker induced superior vena cava syndrome is an unusual complication of pacemaker implantation. Endothelial damage caused by repeated trauma from the lead is thought to be responsible for the stenosis. Malignancy has been historically the most common etiology. However, the increase in use of indwelling venous catheters and cardiac pacemaker has resulted in more patients with superior vena cava syndrome of benign etiology.

Case presentation

A 54-year-old female presented with recurrent spasm and swelling of the neck for the duration of two months. Pacemaker was implanted in 1997 for symptomatic third degree heart block. It was removed in 2007 due to recurrent infection at the lead site. Computed tomography of the chest and venogram were performed which showed stenosis at origin of the superior vena cava with some collateral circulation. She underwent angioplasty by the interventional radiology and is currently free of symptoms.

Conclusions

Our case highlights a relatively uncommon complication of pacemaker. As a primary care physician, one should be aware of this unusual complication of pacemaker. Superior vena cava syndrome should be suspected in patients with history of pacemaker insertion who present to the primary care physician with neck spasm or neck swelling. Primary care physicians should also be aware balloon angioplasty is a reasonable primary intervention in selected patient population.

Persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly. Awareness of this condition may be useful when placement of left-side transvenous subclavian or internal jugular catheters is required. This anomaly may be detected only by chest radiograph following placement of the catheter. The primary endpoints of this study were to analyze the prevalence of PLSVC, measurement of its diameters and the outcome of cancer patients with this anomaly undergoing placement of a long term catheter for nutrition and chemotherapy at the Department of Surgery, of the Second University of Naples, Naples, Italy. A total of 600 consecutive adult patients with hematological or solid tumors admitted to our surgery department for implantation of a central venous catheter (CVC) were considered. The CVC was routinely implanted in the left internal jugular vein under ultrasound guidance. Four cases of PLSVC (0.6% of patients) were observed and confirmed using cine magnetic resonance imaging (MRI). In all cases, the CVC was not removed. Three patients underwent chemotherapy and one patient was subjected to total parenteral nutrition. In the three patients undergoing chemotherapy, dynamic ECG and echocardiography were performed at the end of the treatment. No disturbances of the cardiac rhythm or thrombosis were detected, and heart ejection fraction (EF) was not affected. In conclusion, although PLSVC may be a risky condition, no complications occurred in our study. Thus, PLSVC should not be regarded as a strict contraindication to infusion of chemotherapy or hyperosmolar nutritional solutions. However, further research is needed to confirm our data.

Chronic upper extremity deep vein thrombosis (UEDVT) and superior vena cava syndrome (SVCS) are important and underdiagnosed entities that are associated with significant morbidity, and both are becoming increasingly common due to the use of indwelling catheters and implantable central venous access devices. Currently, as many as 25% of patients with an indwelling catheter are diagnosed with chronic UEDVT or venous stenosis. SVCS is most commonly seen in the setting of malignancy, especially lung cancer and lymphoma. Endovascular management of chronic UEDVT and SVCS is accepted as an important first-line treatment given its high overall success rate and low morbidity as compared with medical and surgical treatments. In this article, the indications for treatment, complications, and success rates of the endovascular management of UEDVT and SVCS are reviewed. Relevant findings on presentation and physical exam as well as various imaging modalities and imaging findings are evaluated. Details of preprocedure evaluation, relevant anatomy, and avoidance of potential complications are discussed.

Introduction

We describe the use of a ablating system to compartmentalise and regionally isolate the atria in paroxysmal and persistent atrial fibrillation (AF).

Methods

40 patients were studied, 25 paroxysmal AF and 14 persistent AF. One patient enrolled was later found to be in left atrial flutter and was excluded. The Cardima Revelation® TX catheter system with Intellitemp® Radiofrequency (RF) energy control device and a Medtronic Atakar® RF generator were used to place wide area circumferential ablations to achieve conduction block into the left and right sided pulmonary veins. Roof lines and mitral isthmus lines were also performed. In patients with persistent AF and in repeat procedures, right atrial compartmentalisation was performed with an anterior superior vena cava (SVC) to inferior vena cava (IVC) line and a septal SVC to IVC line.

Results

At 6 months, 18 of the 39 patients were asymptomatic, 10 had improved symptoms and 22 were in sinus rhythm. In the paroxysmal group, 11 were asymptomatic, 7 had improved symptoms and 16 (64%) were in sinus rhythm. In the persistent group, 7 were asymptomatic, 3 had improved symptoms and 6 (43%) were in sinus rhythm. The total group AF burden was 37.8 ± 5.4 hrs pre-procedure and 23.1 ± 5.1 hrs at 6 months post procedure. Mean temperature, impedance and power recorded at each pole demonstrated effective power delivery at all poles. No catheter charring was observed, complication rates were comparable to standard AF ablation technique.

Conclusion

Linear ablation in the left and right atria to mimic Cox's Maze is feasible and safe using this ablating system.

Superior vena cava (SVC) and inferior vena cava (IVC) pressures were measured serially during laparoscopic cholecystectomy in which the intra-abdominal pressure was maintained at 12mmHg. The influences of alteration of position from 15 degrees head-down to 15 degrees head-up and of the operative procedure of holding the gallbladder up to the right subphrenic space on SVC and IVC pressures were mild. IVC pressure was maintained almost equal to the intra-abdominal pressure during prolonged continuous pneumoperitoneum lasting longer than 60min, while SVC pressure did not change significantly during operation. The discrepancy between SVC and IVC pressures underwent no change during continuous pneumoperitoneum.

Unanesthetized sheep and dogs, previously fitted with indwelling catheters in the aorta, lower vena cava, mesenteric, portal, left hepatic and jugular veins, were given constant intravenous infusions of lymph in which the chylomicron lipids were variously labeled with 3H or 14C. Para-aminohippuric acid was infused into the mesenteric venous catheter for measurement of portal and hepatic venous blood flow. In some animals, alternately labeled free fatty acids bound to albumin were mixed with the lymph to be infused. In both species, chylomicron triglyceride fatty acids were taken up in the region drained by the lower vena cava and portal vein and free fatty acids derived from hydrolysis of these triglycerides were extensively recycled in the blood. Direct uptake of triglyceride fatty acids also occurred in liver and accounted for about 10% of the total triglyceride fatty acids removed from the blood in sheep and 22% in dogs. In sheep, 10% and, in dogs, about 40% of these triglyceride-fatty acids were released into the blood as free fatty acids. The free fatty acids recycled from various regions accounted for a substantial fraction of the chylomicron fat eventually deposited in each tissue. Uptake of chylomicron cholesterol from the blood of sheep occurred primarily in liver and to a small extent in certain tissues drained by the portal vein. The results obtained, together with other available data, demonstrate that chylomicron triglycerides are removed primarily in extrahepatic tissues of both species, while the liver removes cholesterol contained in chylomicron “skeletons” from which most of the triglycerides have been removed. The quantitative differences between transport of chylomicron lipid in sheep and dogs may be related to known differences in the structure of their hepatic sinusoids.

We prospectively evaluated the use of peripherally inserted central venous catheters to provide ongoing venous access in general medical and surgical patients in a Department of Veterans Affairs medical center. Between 1985 and 1988 trained nurses successfully inserted 393 catheters in 460 suitable patients (an 85.4% success rate). Correct catheter tip placement in the superior vena cava was documented in 359 of the 393 (91.3%) catheter insertions, but an additional 30 catheters were in a position deemed adequate for the intended use. The mean duration of catheter use was 27.6 +/- 5.2 (1 standard deviation) days (median 20 days, range 1 to 370 days). A total of 65 patients left the hospital with catheters in place, with the mean length of catheter use at home being 36.2 +/- 6.0 days (range 2 to 266). In all, 79% of the catheters were in use until the successful completion of therapy or patient death; catheter-related complications led to premature catheter removal in the remaining 21%. Catheter-related complications included bland phlebitis (8.2%), occlusion (8.2%), local infection (3.6%), bacteremia or fungemia (2.1%), mechanical failure or rupture (2.6%), venous thrombosis (0.7%), and other (3.3%). One patient required vein excision for the management of suppurative phlebitis, but no deaths were attributed to catheter use. This study illustrates the use and safety of peripherally inserted central venous catheters to provide reliable vascular access over prolonged periods in an elderly veteran population. At our facility, percutaneous central venous catheters and surgically implanted (Hickman or Broviac) catheters are now reserved for use in patients in whom peripherally inserted catheters cannot be placed.

Images

OBJECTIVE--To study the mechanisms underlying the high venous pressure often seen in patients with dilated cardiomyopathy. DESIGN--Retrospective and prospective examination of the pattern of flow in the superior vena cava, cardiac echo-Doppler studies, and recordings of the jugular venous pulse. SETTING--A tertiary referral cardiac centre. PATIENTS PARTICIPANTS--23 patients with dilated cardiomyopathy, all with functional mitral and tricuspid regurgitation. RESULTS--Two patterns of venous pulse were seen: a dominant 'a' wave and 'x' descent, with systolic flow in the superior vena cava (group 1, n = 11), and a dominant 'v' wave with 'y' descent and diastolic flow in the superior vena cava (group 2, n = 12). A comparison of group 1 and group 2 showed: age (mean (SD] 58 (12) v 61 (6) years, left ventricular end diastolic dimension 7.0 (0.7) cm in both groups, right ventricular short axis 3.3 (0.6) v 3.6 (0.5) cm and long axis 7.3 (0.5) v 7.1 (0.7) cm, and duration of tricuspid regurgitation 350 (65) v 370 (50) ms. The RR interval (550 (100) v 680 (80) ms) and right ventricular filling time (150 (30) v 290 (50) ms) were significantly shorter in group 1. In all patients in group 2 right ventricular filling time was more than 200 ms with separate E and A waves on the tricuspid Doppler echocardiogram, while in all group 1 patients it was less than 200 ms with a single summation peak. In nine patients in group 1, the right ventricular filling time was limited by prolonged tricuspid regurgitation and in the remaining two by prolonged isovolumic relaxation time (215 (80) ms), so that it was consistently significantly less than that of the left ventricle. CONCLUSION--In patients with dilated cardiomyopathy, right ventricular filling time may be so short that it limits stroke volume. Such patients can be recognised by a dominant 'a' wave on the jugular venous pulse. Patients in whom the right ventricular filling time was longer showed a dominant 'v' wave. Both groups can present as "congestive heart failure".

Few situations are as vexing for vascular surgeons and their patients as the need for placement of permanent dialysis access when very few access sites remain viable. We recently encountered a patient who typifies this group. After venoplasty of the patient's right femoral and iliac veins, we placed a right superficial femoral artery to inferior vena cava 6-mm polytetrafluoroethylene graft. Under fluoroscopic guidance, we placed the venous limb of the graft directly into the inferior vena cava using a 24-French Gore thoracic aortic graft (TAG) introducer sheath. We secured the venous limb with a purse-string suture at the entrance site in the femoral vein. A standard end-to-side arterial anastomosis was performed. The access has worked without issue for over a year at this point.

To determine the sensitivity and specificity of cross-sectional echocardiography in diagnosing anomalous systemic venous return we used the technique in 800 consecutive children with congenital heart disease and whom the diagnosis was ultimately confirmed by angiography. Cross-sectional echocardiography was performed without prior knowledge of the diagnosis in all but 11 patients, who were recalled because of a known abnormality of atrial situs. The sensitivity of cross-sectional echocardiographic detection of various structures was as follows: right superior vena cava 792/792 (100%); left superior vena cava 46/48 (96%); bilateral superior vena cava 38/40 (95%); bridging innominate vein with bilateral superior vena cava 13/18 (72%); connection of superior caval segment to heart (coronary sinus or either atrium) (100%); absence of suprarenal inferior vena cava 23/23 (100%); azygos continuation of the inferior vena cava 31/33 (91%); downstream connection of azygos continuation, once seen, 21/21 (100%); partial anomalous hepatic venous connection (one hepatic vein not connected to the inferior vena cava) 1/1 (100%); total anomalous hepatic venous connection (invariably associated with left isomerism) 23/23 (100%). The specificity of each above diagnoses was 100% except in one infant with exomphalos in whom absence of the suprarenal inferior vena cava was incorrectly diagnosed. Thus cross-sectional echocardiography is an extremely specific and highly sensitive method of recognizing anomalous systemic venous return. It is therefore of great value of planning both cardiac catheterisation and cannulation for open heart surgery.

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A specific technique of cannulation of the internal jugular innominate vein, presented herein, is not considered an innocuous procedure, but the incidence of serious complications is very low. In this technique a needle-in-catheter unit aids greatly in advancing the catheter through the vein. More than 62 percent of the catheters were left in place for more than five days. There was an 11.4 percent incidence of positive bacterial or fungal cultures from the catheter tip. Routine follow-up chest x-ray films demonstrated all the catheters in the innominate-superior vena cava venous system.

Images

Objective

To retrospectively evaluate the frequency and risk factors for developing thrombus in a systemic vein such as the infrarenal inferior vena cava or the iliac vein, in which a balloon-occluded retrograde transvenous obliteration (B-RTO) catheter was indwelled.

Materials and Methods

Forty-nine patients who underwent B-RTO for gastric varices were included in this study. The B-RTO procedure was performed from the right femoral vein, and the B-RTO catheter was retained overnight in all patients. Pre- and post-procedural CT scans were retrospectively compared in order to evaluate the development of thrombus in the systemic vein in which the catheter was indwelled. Additionally, several variables were analyzed to assess risk factors for thrombus in a systemic vein.

Results

In all 49 patients (100%), B-RTO was technically successful, and in 46 patients (94%), complete thrombosis of the gastric varices was achieved. In 6 patients (12%), thrombus developed in the infrarenal inferior vena cava or the right common-external iliac vein. All thrombi lay longitudinally on the right side of the inferior vena cava or the right iliac vein. One of the aforementioned 6 patients required anticoagulation therapy. No symptoms suggestive of pulmonary embolism were observed. Prothrombin time-international normalized ratio and the addition of 5% ethanolamine oleate iopamidol, on the second day, were related to the development of thrombus.

Conclusion

Development of a thrombus in a systemic vein such as the inferior vena cava or iliac vein, caused by indwelling of the B-RTO catheter, is relatively frequent. Physicians should be aware of the possibility of pulmonary embolism due to iliocaval thrombosis.

Background:

The present study was undertaken to examine the feasibility of venous oxygen measurements in the inferior vena cava (IVC) via a catheter through the umbilical vein. This may serve as a proxy for mixed venous oxygenation and the complications of right atrial cannulation can be avoided at the same time. It has the added advantage of not being affected by atrial right-left shunting.

Results:

The study included 22 neonates requiring mechanical ventilation for respiratory insufficiency. The success rate of catheterization of the IVC via the umbilical vein was 81% and there was no catheter-related complications. Fifty paired blood samples were obtained and analyzed while the patients were hemodynamically stable. Linear regression analysis showed a poor correlation between arterial oxygen tension (PaO2) and the arterial-venous oxygen content difference [C(a–v)O2], r = -0.005, and between PaO2 and the fractional oxygen extraction (FOE), r = -0.114. There was also a poor correlation between arterial oxygen saturation (SaO2) and C(a–v)O2, r = -0.057, and between SaO2 and FOE, r =-0.139. The correlations between venous oxygen tension (PvO2) and C(a–v)O2 and between PvO2 and FOE were r = -0.528 and r = 0.592, respectively. There were good correlations between various oxygen saturation (SvO2) and C(a–v)O2, r = -0.634, and between SvO2 FOE, r = -0.712.

Conclusion:

Venous oxygen measurement in the IVC via an umbilical vein catheter is a simple and safe procedure and provides information about the tissue oxygenation status of critically ill neonates.

A respiratory catheter that is inserted through a peripheral vein and placed within the vena cava is being developed for CO2 removal in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD). The catheter uses a rapidly pulsating balloon to enhance gas exchange. In this study, the CO2 removal performance of our catheter was assessed in acute sheep implants and compared with calf implants, primarily because sheep have cardiac outputs (CO) that are more comparable with human CO and lower than calves. Respiratory catheters (25 mL balloon, 0.17 m²) were inserted acutely in sheep (n = 2) and calves (n = 6) through the jugular vein and placed within the vena cava in two positions: spanning the right atrium (RA) and within the inferior vena cava (IVC). The postinsertion CO in the sheep ranged from 4.1 to 7.2 L/min compared with 6.2 to 15.5 L/min for the calves. The maximum CO2 removal rates (vCO2) were 297 ml/min/m² (calf) and 282 ml/min/m² (sheep) in the RA position and 240 ml/min/m² (calf) and 248 ml/min/m² (sheep) in the IVC position. The respective removal rates between animal models were not statistically different (p values > 0 .05 for all data sets). The dependence of the vCO2 on balloon pulsation was also not statistically different between the animal models.