Vascular Fistula Research Articles

Salvage Treatment for Venous Aneurysm Complicating Vascular Access Arteriovenous Fistula: Use of an Exoprosthesis to Reinforce the Vein after Aneurysmorrhaphy

Objectives We report a new salvage technique for treating venous aneurysms (VAs) complicating vascular access arteriovenous fistula (AVF) using externally reinforced venous aneurysmorrhaphy. Design A retrospective study over a 20-month period from a single centre. Patients Patients presenting to the vascular surgery department, Bordeaux University Hospital for revision of a vascular access AVF were included. Methods Reinforced venous aneurysmorraphy consisted in removal of redundant vessel wall followed by reinforcement using an external prosthetic graft. Patency, diameter and flow were assessed by duplex ultrasound at 1, 6 and 12 months after salvage. Results Thirty-eight eligible patients were identified. Five were excluded because VA was associated with central vein stenosis; the remaining 33 underwent salvage. Indications were rapidly expanding or painful VA in seven cases; VA with frequent bleeding or damaged overlying skin in eight; VA in close relation to a stenosis in two; and VA associated with high-flow rate in 16. Cannulation was attempted after 30 days. Mean follow-up time was 12 S.D. 5 months (range: 4–22). Two repaired AVFs failed. Primary 1-year patency was 93%. No aneurysm or infection occurred. Reduction of high flow was successful in 12 of 16 patients. The remaining four required re-operation. Conclusions Reinforced venous aneurysmorrhaphy is effective in controlling venous dilation and achieving patency. Reduction of high-flow rates was not always achieved. Further study is needed to evaluate long-term efficacy of this treatment.

OP20.02: Nuchal translucency (NT) measurement versus comprehensive early anomaly scan in fetuses with trisomy 21

11–14 weeks screening is moving in many centers from a merely NT measurement to a comprehensive early anomaly scan. Aim of this study was to examine the patterns of sonographic abnormalities found during first trimester screening in fetuses diagnosed with Trisomy 21 (T21). We reviewed data of 62 T21 fetuses diagnosed during a 55 months period that underwent an early anomaly scan. Median maternal age was 37 years and median gestational age was 13 + 0 weeks. Adjusted risk including biochemistry was available in only 10 of all 62 and was not further evaluated. Abnormal karyotype was confirmed by chorionic villus sampling (51/62), amniocentesis (8/62) and postnatal or post mortem karyotyping (3/62). Screening by maternal age (> 34 years) would have detected 43/62 cases (69%). Screening by NT > 95th centile had a sensitivity of 85% (53/62 fetuses). Abnormal ultrasound including abnormal NT was found in 55/62 (89%). Abnormal ultrasound without NT measurement was alone abnormal in 44/62 (71%) and included followings: Cardiac anomaly 25/62 (40%) mainly AVSD in 19/25. Aberrant right subclavian artery in 12/62 (19%), in 7/12 cases combined with a cardiac defect. Abnormal course of ductus venosus and intrahepatic vascular fistula were present in 4/62 cases. 12 fetuses presented as hydrops, skin edema, hygroma, or lateral neck cysts. Nasal bone was absent in 25/62; 40%). In 7/62 fetuses (11%) no sonographic anomaly was found. Those cases were detected by karyotyping for maternal age, postmortem (2×) or postnatally (1×). NT measurement is still the most powerful sign in suspecting T21. In specialized hands the targeted examination of the cardiovascular system (cardiac defect, tricuspid regurgitation, ARSA, aberrant ductus venosus course and Doppler) is a good complementary tool to suspect T21 with a sensitivity of 71% (44/62 with at least one of them).

Percutaneous Embolization of Vascular Fistulas Using Coils or Amplatzer Vascular Plugs

A great variety of different types of vascular fistula are referred to cardiac catheterization laboratories for diagnosis and percutaneous occlusion. In addition, a wide range of devices is available for treating them percutaneously. The objectives of this study were to assess the usefulness and difficulty of treating vascular fistulas percutaneously using controlled-release coils or Amplatzer vascular plugs and to report on the complications and overall outcomes observed with these two devices. Retrospective review of percutaneous embolizations performed from January 2004 through June 2008. In total, 51 vascular fistulas in 30 patients aged from 6 days to 28 years (mean, 8.4 years) underwent successful embolization. The underlying diagnoses were: 27 venous collaterals in 16 patients after the Glenn procedure, four surgical (i.e. Blalock-Taussig) fistulas, 11 pulmonary arteriovenous fistulas in three patients, two aortopulmonary collateral arteries in two patients, one venous collateral in a patient who underwent the Fontan procedure, one aortopulmonary artery fistula in a patient with Scimitar syndrome, one coronary arteriovenous fistula, three systemic arteriovenous fistulas in a newborn, and one fistula from the left atrium to the superior vena cava after the repair of anomalous pulmonary venous return. The lesions were treated percutaneously using 34 vascular plugs and 19 coils. Vascular fistulas can be occluded percutaneously with good Small fistulas can be closed using coils, while vascular plugs are preferable for large lesions. Both devices are highly effective as occluders and no particular difficulty or significant complication was observed.

Application of endovascular stent graft in treatment of traumatic carotid cavernous fistula

Objective To evaluate the effect of Jostent coronary stent-graft in endovascular treatment of traumatic carotid cavernous fistula. Methods Eight patients with traumatic carotid-cavernous fistula were treated by Jostent coronary steat graft from June 2001 to May 2007. Results The stent graft was successfully implanted in the target artery in all patients. The fistula in all patients was removed and the parent arteries kept unblocked. The clinical outcome was favorable, with no operation-related complications occurred. The ang4ogram showed normal patency of the parent arteries, without recanalization of the fistula six months after the stent graft implantation in six patients. Conclusions Stent graft is a useful tool for endovascular treatment of carotid cavernous fistula in selected patients. Further research is needed to optimize the stent graft for further use in cerebrovascular system. Key words: Stents; Embolization, therapeutic; Vascular fistula, cavernous sinus; Carotid arteries

Interventional radiology in the treatment of intracranial vascular injuries and fistulae

Traumatic intracranial vascular injuries are uncommon. However prompt diagnosis and management is essential because of the high morbidity and mortality associated with these conditions. The imaging evaluation and potential endovascular management of traumatic intracranial aneurysms and traumatic intracranial fistulae is discussed.

Thyroid-associated orbitopathy in patients with Hashimoto’s thyroiditis: a case report

Thyroid-associated orbitopathy is a set of ophthalmic symptoms resulting from an autoimmune process in which the swelling of extraocular tissues leads to exophthalmos either caused by hypersecretion and accumulation of glycosaminoglycans in the orbit fibroblasts or being the result of inflammatory processes in the oculomotor. These changes cause eyeball motility disturbances, keratopathy, and the pressure on the optical nerve. Thyroid-associated orbitopathy accompanies Graves' disease in most cases, whereas the Hashimoto's disease in only 5%. In the present case, other reasons for the exophthalmos such as tumors of the orbit and sinuses, intracranial tumors, aneurysms and vascular fistulas and orbit tissue inflammation of different etiology were excluded. Additional examinations showed that thyrotropin level was 26 microlU/ml (normal range 0.27-4.0), antithyroglobulin antibody level was 1763 IU/ml (normal range 0-115), antithyrotropin antibody level was 4.93 IU/l (normal range 0-1), and anti-thyroid peroxidase antibody level was 1609 lU/ml (normal range 0-35). An ultrasound examination showed a thyroid gland of 9.8 ml volume. A cytological presentation obtained by thin-needle aspiration biopsy demonstrated inflammatory infiltration of lymphocytes, indicating an autoimmune process. The iodine uptake after 24 hours was 9%. The active form of orbitopathy was diagnosed in the patient with hypothyreosis in the course of Hashimoto's disease. Moreover, the coexistence of another autoimmune disease, pernicious anemia was diagnosed. The administration of the methylprednisolone pulse therapy and levothyroxine caused remission of ophthalmic symptoms, and euthyreosis was obtained. Our report presents a rare coexistence of thyroid orbitopathy and Hashimoto's disease.

Monitoring of ultrasonography in artificial vascular graft for arteriovenous fistula

To evaluate the monitoring of ultrasonography in artificial vascular graft for arteriovenous fistula and its complications in patients with chronic renal failure. Eighteen cases of artificial vascular graft arteriovenous fistula after four to six weeks were enrolled. The diameter, the peak velocity and blood flow were examined in arterial fistula. And the artificial vascular diameter, the peak velocity and blood flow of artificial vessels next to artery were all examined and analyzed. And the patients with symptoms in the upper extremity were tested by ultrasound. Intravascular blood showed good filling in fistula and artificial blood vessels in four to six weeks after artificial vascular graft for arteriovenous fistula by color doppler ultrasonography. The arterial fistula diameter, the peak velocity and blood flow were (3.61 +/- 0.68) mm and (298.56 +/- 93.42) cm/s and (583.62 +/- 216.77) ml/min. Artificial vascular diameter in (4.47 +/- 0.61) mm, the peak velocity and blood flow were (219.37 +/- 68.42) cm/s and (325.23 +/- 117.12) ml/min in the artificial blood vessels next to artery. Seven patients with upper extremity discomfort were examined by ultrasonography. One case was serum swollen. Three cases were thrombosis in artificial vessels. One case was pseudoaneurysm. Two cases were edema. Ultrasonography plays a significant clinic role in testing artificial vascular graft for arteriovenous fistula and its complications.

The Effect of Hemoglobin Level on Arteriovenous Fistula Survival in Iranian Hemodialysis Patients

Objective End-stage renal disease (ESRD) poses steadily growing challenges to health care systems worldwide. Renal replacement therapy with hemodialysis (HD) or kidney transplantation is the only possibility for ESRD patient survival. A complete correction of anemia in HD patients may lead to an increased risk of vascular arteriovenous fistula (AVF) primary failure; some studies have demonstrated that decreased levels of hemoglobin (Hb) had adverse effects on cardiac and brain function. This study was designed to evaluate the impact of different risk factors, especially the Hb level on AVF survival. Methods Prospective observational data were analyzed from a non-randomized sample (n=100) of HD patients who were referred for first AVF creation between April 2005 and December 2006 with <1 month on HD. The relative risk (RR) of access primary failure was evaluated in four different groups of patients divided according to their Hb levels (<8, 8–10, 10–12, and >12 g/dL). Other factors possibly influencing vascular access (VA) survival were also considered including gender, age, smoking, diabetes, hypertension, parathyroid hormone levels, ACE inhibitor intake and triglyceride levels. The analyses were performed using SPSS v.11.5, Kaplan-Meier analysis, Cox's regression and log rank test. Results There was a statistically significant higher risk of AVF primary failure in patients with Hb <8 g/dL (RR=1.41; p=0.01), diabetes (RR=1.21; p=0.05), age>60 yrs (RR=1.41; p=0.06) were identified as predictive factors for AVF primary failure. ACE inhibitor intake (RR=0.45; p=0.01) was found to be protective. Conclusion Correction of serum Hb level can lead to a better result in VA survival and ACE inhibitor intake was found to be a protective factor.

In-center daily on-line hemodiafiltration: a 4-year experience in children

Our daily dialysis program was started in September 2002: in-center daily on-line hemodiafiltration (DIH) was carried out in 3-hour sessions, 5 - 6 times weekly, on-line assessment KT/Vurea of minimal 1.5 per session, polysulfone membranes. 12 children were included: median age 7.4 years (2.10 - 16.8 years), renal residual function less than 3 ml/min/1.73 m2 (Kcreat + Kurea/2), vascular access central catheter (n = 4) or fistula (n = 8), 7/12 being converted from peritoneal dialysis to DIH. Median follow-up on DIH was 11 months (4 - 43 months), endpoint was kidney transplantation (11/12) or transfer to another center (1/12). Monthly assessments of dialysis parameters (KT/Vurea, predialysis phosphatemia), diet survey (3 consecutive days), medications (number of antihypertensive drugs, phosphate chelators, potassium chelators) and statural growth were performed. At start of DIH, diet intake due to medical prescription and limited appetite was restrictive with limitation in water, salt (20 mmol/day), potassium and proteins (median 35 g/day, range 20 - 80 g); only 2/12 children were free of antihypertensive drugs, all received phosphate and potassium chelators, and growth retardation occurred (7/12 in prepubertal children, median height SDS -1.52) despite rhGH therapy (5/12 patients). At the end of DIH, diet was free, protein intake high (2 - 3 g/kg/day, range 30 - 100), 10/12 children were free of antihypertensive drugs, 4/12 received potassium chelators, 1/12 received phosphate chelators. All the prepubertal children at inclusion (n = 7) showed catch-up growth with a median growth rate of 0.8 cm/month (0.5 - 1.6 cm/ month). DIH allowed to maintain predialysis phosphatemia in a low normal range (median 1.23 mmol/l, range 1.65 - 0.63), without (11/12 children) need of phosphate chelators. Thanks to DIH children, parents and team care discovered during DIH a new way of life with motivated children, showing natural compliance (no diet restriction, no or few drugs), and most of all children developing with catch-up of growth.

Heparin-induced Thrombocytopenia in a Uremic Patient Requiring Hemodialysis

Heparin-induced thrombocytopenia (HIT) is an uncommon but potentially serious complication of hemodialysis, and subsequent reexposure to heparin after the disappearance of antiheparin-PF4 complex antibodies (HIT antibody) has been controversial. We report a 60-year-old woman who was sensitized to unfractionated heparin (heparin) as anticoagulant during hemodialysis (HD) and heparin flush on a nonsession day. The patient suddenly developed acute systemic reactions with acute pulmonary embolism a few minutes after manipulation with heparin flush on day 9, a nonsession day. Although there was no evidence of pulmonary embolism on a pulmonary scintigram on the next day, the fifth HD session was discontinued owing to recurrence of acute systemic reactions and massive clots in the dialyzer 30 min into the session. After confirmation of the presence of HIT antibody and maturation of vascular access fistula, a sixth HD session was carried out with argatroban, a synthetic direct thrombin inhibitor, with a bolus of 10 mg and continuous infusion of 0.5 mg/kg/hr as an alternative to heparin. Optimal dose adjustment of argatroban through activated partial thromboplastin time (APTT) monitoring led to a bolus of 5 mg and continuous infusion of 0.15 mg/kg/hr. The patient's HD treatment at the same doses 3 times a week followed an uneventful course over 6 months. HIT antibody was seronegative about 40 days after the cessation of heparin treatment. Reexposure to heparin was attempted with the monitoring of HIT antibody and platelet counts before and after the sessions on day 210. The titers of HIT antibody compared with before the level of reexposure showed a transient insignificantly small peak, and dialysis with heparin has been maintained to date with no recurrence of HIT. The measurement of HIT antibody titer could be useful in assessing not only the effect of argatroban to replace heparin but also in predicting the recurrence of HIT due to reexposure.

Progressive Unilateral Hemispheric Atrophy in an Infant with Neurofibromatosis

Cerebrovascular diseases are rarely seen in neurofibromatosis type 1. These include vascular occlusive disease, moyamoya vessels, aneurysms, arteriovenous malformations and fistulae. We describe the case of an infant with genetically proven neurofibromatosis type 1 and progressive brain hemiatrophy over months, due to primary narrowing of intracranial carotid artery branches, as demonstrated by successive brain imaging. She presented with refractory seizures and a progressive hemiparesis associated with developmental delay. Surgical material from hemispherotomy done at 18 months showed severe abnormalities of the small vessels. Cerebrovascular changes seen in neurofibromatosis can be diffuse and progressive, with secondary hemiparesis, epilepsy and developmental delay.

Impact of obesity on arteriovenous fistula outcomes in dialysis patients

Fistula use for dialysis is less frequent among obese than non-obese patients. This discrepancy may be due to a lower rate of fistula placement in obese patients, a higher primary failure rate (fistulas that are never usable for dialysis), or a higher secondary failure rate (fistulas that fail after being used successfully for dialysis). Using a prospective, computerized vascular access database, we identified all patients receiving a first fistula or graft at our institution during a 2-year period. The access outcomes were compared between obese (body mass index (BMI) >or=30 kg/m2) and non-obese (BMI<30 kg/m2) patients. Fistula placement was equally likely between obese and non-obese patients (47.4 vs 47.1%). The primary failure rate of fistulas was similar in both groups (46 vs 41%, P=0.45). Among those fistulas that were usable for dialysis, the secondary survival was worse in obese patients (hazard ratio 2.74; 95% confidence interval (CI), 1.48-7.90; P=0.004). Secondary fistula survival in obese vs non-obese patients was 68 vs 92% at 1 year, 59 vs 78% at 2 years, and 47 vs 70% at 3 years. On multiple variable survival analysis with age, sex, race, diabetes, coronary artery disease, peripheral vascular disease, fistula location, surgeon, and obesity in the model, obesity was the only significant factor predicting secondary fistula failure (hazards ratio 2.93; 95% CI, 1.44-5.93; P=0.004). In conclusion, long-term fistula survival is worse in obese than non-obese patients, owing to a higher secondary failure rate.

Posterior “nutcracker” phenomenon: hemodynamic relevant aorto‐retroaortal renal vein fistula leading to fatal right heart failure

A rare complication of an aneurysm of the abdominal aorta is the so-called "posterior nutcracker phenomenon", which describes compression of a retroaortal renal vein between the abdominal aorta and the vertebral column. The clinical presentation is flank pain and hematuria, which are usually caused by a renal (respectively ureteral) calculus or neoplasia. Another rare differential diagnosis for these very common clinical symptoms is an aorto-left renal vein fistula (ALRVF), which is a spontaneous vascular fistula, usually also associated with an aortic aneurysm, infrequently a result of abdominal trauma.

Treatment of postpriapism erectile dysfunction by closure of persistent distal glans-cavernosum fistulas 5 years after shunt creation

Erectile dysfunction is common after the formation of a glans-cavernosum shunt for intractable priapism. Often patients require placement of a penile prosthesis to restore sexual function. We report a case of restoration of full erections after reversal of a glans-cavernosum shunt in a 30-year-old man who had been treated for priapism 5 years previously. On the basis of our experience, it seems reasonable to attempt shunt reversal for correction of erectile dysfunction in selected patients who likely have a persistent vascular fistula.

INVITED COMMENTARY

Technologic advances have facilitated the management of many postsurgical complications. When applied to the correct patient, at the appropriate time, these techniques can facilitate recovery of the patient and avoid the morbidity and possible mortality associated with an operative reintervention, often in a critically ill patient. Crucial to the success of these endeavors is early intervention when a complication develops, and also the ability to recognize the failure of nonoperative intervention early enough in the course to resort to an alternate plan to salvage the situation. Langer and colleagues report on the use of stents to manage esophageal anastomotic leaks, both cervical and intrathoracic. Despite many modifications, this complication still occurs in 10% to 33% of resections. The authors utilized the Polyflex stent (Willy Ruesch GMBH, Kernan, Germany) to endoscopically manage this vexing, and potentially lethal complication. The goals of stenting appeared twofold; one to prevent death from continued soiling of the mediastinum, and one for the cervical anastomoses, prevention of the strictures often associated with a cervical leak. This report clearly describes the good, the bad, and the ugly associated with this technique. The good is those patients whose leaks were successfully managed nonoperatively. Their leaks were sealed and no further operative intervention was required. The bad were the patients who succumbed despite having been stented, leaving one to question the timeliness and adequacy of the intervention. Would takedown of the anastomosis and/or diversion been the optimum choice? The ugly may be seen in an early and a late phase. The early phase occurring in the patients whose anastomoses were further disrupted by stent placement, thus requiring an emergent operation to achieve any chance of survival. The late phase we can foresee in the group of patients left with those “benign” stents in place. Gaissert and colleagues [1Gaissert H.A. Grillo H.C. Wright C.D. et al.Complications of benign tracheobronchial strictures by self-expanding metal stents.J Thorac Cardiovasc Surg. 2003; 126: 744-747Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar] have recently described the problems resulting from the placement of stents in the airway in lieu of definitive surgical repair. One has to be concerned regarding the development of vascular and airway fistulas in the patients left stented indefinitely. Stenosis of the esophagus proximal to these stents will not leave us much room to work, and result in a miserable existence for the patient. As esophageal surgeons we should keep an open mind to the use of these devices in the management of our postoperative complications, but not be lulled into a false sense of security that a nonoperative approach is always better than a well done operation. Management of Postoperative Esophageal Leaks With the Polyflex Self-Expanding Covered Plastic StentThe Annals of Thoracic SurgeryVol. 79Issue 2PreviewEsophageal anastomotic leaks can lead to prolonged hospitalization. In this article we present our experience with the placement of the Polyflex self-expanding plastic stent (Willy Ruesch GMBH, Kernen, Germany) for leak occlusion. Full-Text PDF

Computed Tomography and Magnetic Resonance Angiography in Cervicocranial Vascular Disease

Although catheter angiography, or digital subtraction angiography (DSA), is still regarded as the gold standard for imaging of cervicocranial vascular disease, its morbidity, cost, and time-consuming features have prompted the development of noninvasive techniques based on computed tomography (CT) and magnetic resonance imaging. With the advent of powerful software, CT and magnetic resonance angiography are complementing and, in some cases, even replacing DSA in the diagnostic evaluation of carotid atherostenosis, unruptured aneurysms, dissections, stroke, penetrating trauma to the neck, and dural venous sinus occlusive disease. They offer advantages over DSA not only in reduced morbidity and time-saving but also in assessment of brain parenchyma, quantitative perfusion, and abnormalities of vessel walls. In the evaluation of blunt neck injuries and intracranial vascular malformations, fistulas, and vasculitis, CT and magnetic resonance angiography still do not provide as much information as DSA.

P0384 THREE CASES OF CONGENITAL INTRAHEPATIC PORTOSYSTEMIC VENOUS SHUNT IN NEONATES.

Introduction: Congenital intrahepatic portosystemic venous shunt (CIHPSS) are very unusual abnormalities. Only 50 publications have been counted. They are defined as macroscopic communications between the portal and the systemic venous circulation. They are entirely or partially located within a heathy liver that functions without portal blood. When discovered early in life, they are in favour of a malformative origin of the shunt. HEREIN, we report three neonate observations with their icon-çography. For the case n°1, it was a color Doppler and ultrasound scanning for a fever checkup,, which diagnosed the CIHPSS. between the right portal vein and the right-sus hepatic vein. In the two other one, it was the antenatal color Doppler and ultrasound scanning which diagnosed shunts during the third term of pregnancy. Those three shunts were considered as type II, according to the PARK’s classification system for IHPSS anormalies, because they link up a portal branch to an hepatic vein in a same parenchymal segment. Methods: Case n°1 is now 6 years old and is still asymptomatic. A clinical, biological and ultrasonographic examination, once a year is sufficient. The vascular fistula resolved spontaneously when case n°2 was 28 months old and when case n°3 was 8,5 months old. Results: DISCUSSION: Normally, toxic metabolites of nutrients and residual activity of pancreatic enzymes are degraded by the liver. Here, due to the shunt, they bypass directly into the systemic circulation. Then, hyperammoniemia, trimethylaminuria, hyperinsulinemia, pulmonary hypertension or congestive heart failure can appear. THERAPY: Because of the rarity of this disorder, the choice of treatment is controversial. It depends on the natural course of the disease, but the majority of patients did not have symptoms until their 6th decade. Initially, the spontaneous resolution is expected. If hepatic encephalopathy or heart failure progress, some treatment may indicate: angiographic intervention with percutaneous coil embolisation, surgical intervention such as shunt ligation and hepatic resection or realisation of an alternative portosystemic shunt. Conclusion: CIHPSS have been thought to be uncommon, but improvement of imaging (US, CT, MRI) have shown even asymptomatic intrahepatic shunts in an increasing number of patients. Spontaneous resolution is frequent. Metabolic and hemodynamic repercussions will guide the management in other cases.

Potential Use of MR Angiography for Diagnosis and Postinterventional Follow-Up of a Posttraumatic Arteriovenous Fistula

Background: Arteriovenous fistulae represent a common sequel following injury to blood vessels. They can be assessed by several ways including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and conventional angiography. MRI has proven to be a useful technique in the visualization of the extent of vascular disorders. However, magnetic resonance angiography (MRA) has not yet been established as a standard modality for evaluation of feeding and draining vessels. Case Study: We report on the case of a 32-year-old man suffering from a clinically symptomatic vascular fistula following inguinal stabbing in order to present the role of contrast-enhanced MRA for diagnosis and postinterventional follow-up of a peripheral vascular disorder.

New method to create a vascular arteriovenous fistula in the arm with an endoscopic technique

We describe a new technique in which the basilic vein is transposed subcutaneously with endoscopic surgery to create a vascular access in the arm. The vein was harvested with the Endoscopic Vascular Surgery System (Olympus Co, Tokyo, Japan). We could harvest a vessel about 25 cm long with endoscopy. After vessel transposition, an arteriovenous fistula was created in the usual manner. In all 10 patients, we created an effective blood access as scheduled before surgery. We could use the arteriovenous fistula 6 days after surgery and get blood flow in all cases. (J Vasc Surg 2002;36:635-8.)

Effects of resuscitation with hydroxyethyl starch (HES) on pulmonary hemodynamics and lung lymph balance in hemorrhagic sheep; comparative study of low and high molecular HES

Synthetic starch solution, such as hydroxyethyl starch (HES), has been used clinically to restore cardiovascular volume in patients with hemorrhagic shock. Several HES solutions are available clinically, but each HES has a broad range of molecular mass fractions. We performed comparative studies of extremely low and high molecular HES to evaluate the effects of these HES solutions on lung lymph filtration during resuscitation. We prepared awake sheep with vascular monitoring and lung lymph fistulas. After baseline measurements, animals were bled from an arterial line to maintain shock. After 2 h of hemorrhagic period, the following three solutions were infused over 1 h, respectively. Experiment (Exp) 1 ( n=6); low molecular HES; (molecular weight (MW) 70 000, substitution fractions 0.5–0.55, Exp 2 ( n=6); high molecular HES; (MW450 000, substitution fractions 0.65). Exp 3 ( n=6); normal saline (NS). The quantity of solution was determined as the same volume of blood lost to induce hemorrhagic situation in each animal (Exp 1; 940±36 ml, Exp 2; 910±50 ml, Exp 3; 920±42 ml). Both low and high molecular HES could restore the systemic artery pressure and cardiac output, and significantly increased pulmonary microvascular pressure equally, which were significantly higher than those in normal saline. However, actual oncotic pressure gradient (plasma-lymph) rose transiently during low molecular HES infusion, while high molecular HES widened the oncotic pressure gradient even after the cessation of the infusion. Lung lymph flow during and after resuscitation with low molecular HES and NS rose significantly from the pre-shock baseline. There was no significant difference in increased lung lymph flow between low molecular HES and NS. However, lung lymph flow after high molecular HES was significantly less than that after low molecular HES. These data suggest that low molecular HES is as useful a plasma substitute as high molecular HES, but has a possibility to increase lung lymph filtration during the early phase of resuscitation.