Duplex Doppler Ultrasound Scanning Research Articles

Fetal Vein of Galen Aneurysmal Malformation (VGAM) Detected at 36 Weeks: Review of Literature and Case Report

Abstract Vein of Galen malformation is a rare intracranial vascular lesion most often concomitant with poor prognosis when associated with high-output cardiac failure. We present a case that was diagnosed late in the third trimester, but due to the limitations in our local settings, immediate operative intervention could not be done. A 24-year-old primigravida was sent for a routine 36-week obstetric ultrasound scan (USS), which revealed a midline cystic structure with mosaic color signals on a duplex Doppler USS within the fetal head. The unavailability of fetal magnetic resonance venography (MRV) delayed confirmation until the postnatal period. An MRV done on the second day of delivery showed a dilated, tortuous midline structure in the region of the vein of Galen, which confirmed the findings. Echocardiography revealed multiple cardiac lesions. Although, both antenatally and at birth, there was no cardiac failure, the baby died on the seventh day of life from possible cardiac compromise.

Sphenoid ridge meningioma presenting as ischemia stroke

A previously healthy 49-year-old woman presented to the emergency room with acute onset of left hemiparesis and dysarthria. Neurological examination showed a left central-type facial palsy. The muscle power grade 3 in the upper limbs and grade 4 in the lower limbs. Complete blood count, chest radiograph, ECG, echocardiogram and a duplex Doppler ultrasound scan of the carotid artery on the symptomatic left side were also normal. Magnetic resonance imaging (MRI) with angiography (MRA) (A,B,C,D,E,F) confirmed the left sphenoid wing mass that had displaced and distorted the left middle cerebral artery (MCA) postero-superiorly, thereby resulting in an acute thromboembolic MCA territory infarct. The patient underwent Simpson grade III resection through the pterional approach. The vessel compression was resolved, but the hemiparesis persisted. The pathology revealed a meningothelial meningioma. She was maintained on oral aspirin at 160 mg/ day, after a 6-month rehabilitation programme, the patient recovered with mild paresis in the left upper extremity. Meningiomas may present with slowly progressive signs of neurological deficit, headache or focal seizures. Exceptionally, they may compress surrounding major cerebral blood vessels and compromise cerebral blood flow resulting in acute neurological symptoms attributable to vascular insufficiency of a specific cerebral blood vessel thereby simulating classical ischemia stroke.

Platelet-Rich Plasma Therapy for Male Sexual Dysfunction: Myth or Reality?

Platelet-rich plasma (PRP) found its use in treating different conditions and diseases, because concentrated plasma PRP consists of many growth factors. Their interaction with surrounding cells, intracellular matrix, and mediators at the site of injection leads to tissue regeneration. Angiogenic, vasculogenic, and regenerative effects of PRP may be used for erectile dysfunction (ED) and Peyronie's disease (PD) treatment. To present a current data review of preclinical and clinical trials on PRP use for treating ED and PD. Up-to-date literature on PRP use for ED and PD treatment was analyzed. The search was based on Pubmed, Cochrane Library, clinicaltrials.gov databases, with the following key words: "platelet-rich plasma" and/or "erectile dysfunction" and/or "Peyronie's disease" and/or "sexual dysfunction." The main outcome measures for preclinical trials on ED were erectile function, assessed with intracavernous pressure, and pathologic analysis of penile tissue. The main outcome measures for clinical trials on ED included penile duplex Doppler ultrasound scanning and validated questionnaires. The main outcome measures on PD were pathologic analysis of penile tissue for preclinical trials, as well as penile duplex Doppler ultrasound scanning, penile curvature angle measuring, and validated questionnaires for clinical trials. 4 preclinical and 6 clinical trials were described and analyzed in this article. Limitations for both preclinical and clinical trials included small groups, short follow-up periods, a lack of control groups or groups with placebo, and the lack of quality and quantity analysis of PRP. Available data show the lack of adverse reactions with PRP treatment. The studies that we found were limited by small groups. This is why the data on safety and effectiveness should be taken carefully. However, it is important to mention that PRP therapy has the potential for treating male sexual dysfunction and may be useful in andrology. Epifanova MV, Gvasalia BR, Durashov MA, etal. Platelet-Rich Plasma Therapy for Male Sexual Dysfunction: Myth or Reality? Sex Med Rev 2020;8:106-113.

Evaluation the velocity of vocal fold movements in adults by duplex Doppler scanning

To evaluate the velocity of vocal fold movements by duplex Doppler scanning in adults during breathing, talking and phonation. Twenty healthy volunteers (18 women and 2 men) without of voice problems were investigated with scanners Logic-7 or Aloka 1100 by the linear transducer 7-10 MHz. The thyroid cartilage was used as an acoustic window. The dependence between the vocal fold velocity and volume and pitch of the voice were estimated using Spearman correlation. The velocity of movements of the vocal folds during breathing was from 5 to 16 cm/s, during talking and phonation - from 9 to 110 cm/s. Coefficient of Spearman correlation between the voice pitch and the vocal fold velocity was +0.9±0.1 an average, between volume of the voice and the vocal fold velocity was - 0.7±0.1. Duplex Doppler ultrasound scanning of the larynx allows measuring the velocity of vocal fold's movements during breathing, conversation and phonation. The fold's velocity increases with increasing of the voice volume and decreases with increasing the voice pitch. Duplex Doppler ultrasound scanning may be useful for early detection of disorders of mobility of the vocal folds.

Determination of normal portal vein congestive index on ultrasound scan among adults in Zaria, Nigeria

Background: Portal hypertension is a major abnormality of the portal venous system and it is a commonly encountered clinical condition with multiple causes and several sequelae. The need for an imaging parameter that will aid its early diagnosis cannot be overemphasized, bearing in mind that portal pressure monitoring devices are not available in most tertiary hospitals in Nigeria. This prospective study was aimed at using ultrasound to determine the normal Portal Vein Congestive Index among adults in Zaria, Nigeria. Patients and Methods: The study was conducted over a period of 6 months spanning 15 th November 2011 to 14 th May 2012 at the Radiology Department of Ahmadu Bello University Teaching Hospital, Zaria. Following an overnight fast by the 186 eligible participants, the portal vein diameter, cross sectional area and flow velocity were obtained using ultrasound Doppler equipment (Mindray diagnostic ultrasound system, Model DC-3, 2010-2012, Nanshan, Shenzen, PR China). B-Mode gray-scale for the assessment of dimensions, and Duplex Doppler Ultrasound Scan techniques for interrogation of the flow pattern and velocity. These parameters were then used to obtain the congestive index of the subjects. Results: The portal vein hemodynamic parameters were as follows mean (SD): Cross sectional area, 1.097 cm 2 (0.203) (ranged 0.89-1.30); mean flow velocity, 15.44 cm/s (2.628) (ranged 12.80-18.10); and congestive index, 0.0722 cmS (0.0135) (ranged 0.0587-0.0857). All measurements in males were significantly higher than those in females (P < 0.001); and the portal vein congestive index increased significantly with age (P = 0.006).Conclusion: Reference values of normal congestive index of the portal vein have been established and may be used for the assessment of patients with liver diseases or portal hypertension in this environment.

Calf muscle stimulation with the Veinoplus device results in a significant increase in lower limb inflow without generating limb ischemia or pain in patients with peripheral artery disease

Increase in arterial inflow to the lower limbs is important to obtain functional improvement in peripheral artery disease (PAD) patients with claudication. The aim of this study was to assess the effect of electrical stimulation of calf muscles on arterial inflow and tissue oxygen content in PAD in the area of stimulation. Fifteen adult patients [mean (standard deviation) age, 62 (12 ) years; height, 165 (8)cm; weight, 76 (13) kg; lowest ankle-brachial index 0.66 (0.19)] with stable arterial claudication were recruited. All patients performed a treadmill test (3.2 km/h, 10% slope) associated with a transcutaneous oximetry test expressed as decrease from rest of oxygen pressure (DROP) index values (calf changes minus chest changes from rest) with a maximum walking distance (median [25th/75th percentiles]) of 295[133-881] m. The DROP index on the symptomatic side was -25 [-18/-34] mm Hg. On another daythe patients underwent electrical stimulation in the seated position on the leg that was the most symptomatic on the treadmill. After resting values were recorded, the gastrocnemius was stimulated for 20minutes at increasing contraction rates at 5-minute steps of 60, 75, 86, and 100bpm on the most symptomatic side. Arterial blood inflow with duplex Doppler ultrasound scanning of the femoral artery, DROP transcutaneous oxygen pressure value, and oxygen concentration (O2Hb) from the near-infrared spectroscopic signal of the calf were recorded on both sides. Patients were instructed to report eventual contraction-induced pain in the stimulated calf. Results are given as mean (standard deviation) or median [25th/75th percentiles] according to distribution, and the level of statistical significance was set at P< .05 on two-tailed tests. Lower limb inflow (mL/min) was 64 [48/86] vs 63 [57/81] (P> .05) before stimulation, 123 [75/156] vs 57 [44/92] (P< .01) at 60bpm, 127 [91/207] vs 49 [43/68] (P< .01) at 75bpm, 140 [84/200] vs 57 [45/71] (P< .01) at 86bpm, and 154 [86/185] vs 55 [46/94] (P< .01) at 100bpm on the stimulated vs nonstimulated limb, respectively. No apparent decrease or significant leg difference was observed in DROP index or O2Hb values. None of the patients reported contraction-induced pain in the leg. Electrical stimulation of calf muscle with the Veinoplus device results in a significant increase of arterial inflow without measurable muscle ischemia or pain. Potential use of this device as an adjuvant treatment to improve walking capacity in PAD patients remains to be evaluated.

Pattern of duplex doppler ultra sound scans in Jos University Teaching Hospital

Doppler ultrasound scan is a non invasive diagnostic tool used in the evaluation of vascular and perivascular lesions. It is gaining a wider acceptance over other methods of vascular evaluation which are expensive and invasive. We aimed at evaluating the indications and findings of duplex doppler ultrasound scans performed in this centre. This was a retrospective study of all consecutive patients that had doppler ultrasound scans from January 2000 to December 2004. One Hundred and sixty five (165) Doppler ultra sound scans were performed on 115 patients. Thirty nine patients had a double scan while 19 had repeated scans. The study population was aged between 2-90 years with a mean age of 44.5 +/- 17.5 years. There were 86 (52.1%) males and 79 (47.9%) females giving a male to female ratio of 1:1.67 (41%) of the doppler scans were for deep vein thrombosis while peripheral vascular disease and vascular aneurysm accounted for 24 (14.5%) and 23 (13.9%) respectively, see Table 1. Reduction in vascular blood flow was the most common doppler finding seen in 34 (20.6%) patients followed by visible thrombi in 14 (8.5%) patients. Deep vein thrombosis is the most common indication for doppler ultrasound scan in our practice.

Genetic prothrombotic mutations are common in neonates but are not associated with umbilical catheter-associated thrombosis

To evaluate the prevalence of hereditary prothrombotic mutations, and their effect on the incidence and severity of umbilical arterial or venous catheter (UAC or UVC)-associated thrombosis. All neonates with a UAC or UVC were studied prospectively for the presence, severity and timing of thrombosis with duplex Doppler ultrasound scan. Genetic testing for factor V Leiden (FVL), prothrombin mutation (PTm) and methylene-tetrahydrofolate reductase (MTHFR) mutations was performed using PCR and restriction fragment length polymorphism assays. Umbilical catheter (UC)-associated thrombosis developed in 16/53 (31%) neonates; 23% of UACs and 22% of UVCs were associated with thrombosis. The prevalence of a significant prothrombotic mutation was present in 10/51 (20%) of infants: FVL (8%), MTHFR667 homozygosity (10%), MTHFR1298 homozygosity (2%) and PTm (0%). There was no increase in the risk of UC-associated thrombus in patients carrying these prothrombotic mutations; our study had the power to detect a 2.5-fold increased risk of thrombosis for any of these significant mutations. In addition, MTHFR667 heterozygosity was found in 41% of infants and MTHFR1298 heterozygosity in 52% and also were not associated with increased risk of UC-associated thrombus. The risk of MTHFR double heterozygosity (db het) was 14%, the risk of a significant or db het was 17/51 (33%) and the risk of any mutation was 90%. Prothrombotic genetic mutations are common in our Neonatal Intensive Care Unit population but do not appear to increase the risk of UC-associated thrombosis.

Vein graft anastomoses with magnets

Performing vascular anastomoses requires complete circumferential access and is time-consuming and technically challenging. The purpose of our study was to assess a sutureless magnetic device for anastomosing vein grafts. Oval magnets with a lumen were placed in six male foxhounds. The femoral artery was ligated and an 8 cm length of femoral vein was harvested and reversed. After a 4 mm venotomy or arteriotomy, one magnet was inserted into each vessel lumen and a second magnet was placed outside the vessel but aligned directly over the intraluminal magnet, forming a magnetic port in each vessel. The graft and target vessels were then allowed to self-align and seal, creating a side-to-side anastomosis. Patency was confirmed with duplex Doppler ultrasound scans after 6 and 13 weeks and during explantation after 14 weeks. At that time, the contralateral femoral vein was harvested and an acute graft was created as a control. Macroscopically there was no sign of stenoses or aneurysms. After explant, saline was perfused through all grafts and the hydrodynamic resistance was quantified. There was no significant difference in resistance between the acute and 14-week grafts indicating stenosis. Microscopic examination of 14-week anastomoses showed that all blood-contacting surfaces were well-endothelialised. The magnetic vascular coupler allowed sutureless anastomoses between blood arteries and veins. This device might prove useful for anastomosis of large and small vessels, as well as for anastomosis or approximation of non-vascular structures such as peripheral nerves, fallopian tubes or ureters.

Preoperative vascular imaging in pediatric liver transplantation

Background/Purpose There is a considerable variation in the use of vascular imaging techniques in the preoperative assessment of children scheduled for liver transplantation. Duplex Doppler ultrasound scan (US), magnetic resonance angiography (MRA), and conventional angiography are used to varying extents. The authors compared the results of preoperative vascular imaging studies with operative findings to determine their accuracy and usefulness. Methods Results of preoperative vascular imaging in 37 consecutive children undergoing cadaveric liver transplantation were compared with operative findings. Those undergoing relatively elective transplantations were investigated by US and MRA (group 1), whereas those requiring urgent transplants were assessed only by US (group 2). Results The median age of the cohort (15 boys; 22 girls) was 4 years (19 days to 16 years) and the median weight was 17 kg (2.9 to 82 kg). In group 1 (n = 26), 20 children had a normal-caliber, patent portal vein at transplant and 6 had a narrow but patent portal vein requiring venous reconstruction in 4. The sensitivity and specificity of MRA in the detection of an abnormally narrow portal vein were 100% (6/6) and 95% (19/20), respectively. If reversed or absent flow in the portal vein on US was taken as an indication of a potentially abnormal vein, the sensitivity and specificity of Doppler US were 83% (5/6) and 95% (19/20), respectively. Magnetic resonance angiography revealed arterial anomalies in 4 children but failed to detect small accessory hepatic arteries in 5. The single patient with an aberrant vena cava was identified by MRA. In group 2 (n = 11), venous findings at operation and on US were concordant in 10 (91%) cases; one infant with reversed flow in the portal vein on US had a thrombosed vein at surgery. Magnetic resonance angiography was useful in 2 patient groups: those with reversed flow on Doppler US or suspected portal vein thrombosis in whom an abnormal portal vein was present in 86% (6/7) and infants with the biliary atresia splenic malformation syndrome who had multiple venous and arterial anomalies. Conclusions A detailed Doppler examination of the hepatic vasculature by an experienced sonographer/radiologist provides sufficient vascular imaging for most children scheduled for cadaveric liver transplantation. Routine MRA is recommended in children with the biliary atresia splenic malformation syndrome and in those with abnormal duplex Doppler US findings. Although there are limited data in this study, MRA is also valuable in children with Budd-Chiari syndrome, liver tumors, or a previous portosystemic shunt.

Anastomoses for vascular shunt, arterial graft, and flap vascularization performed using magnets

Abstract Introduction: The purposes of these studies were to demonstrate the potential for using magnets to perform sutureless vascular anastomoses in clinically relevant models, including vascular arteriovenous shunts, arterial bypass grafting, and vascularization of surgical flaps. Methods: Oval 0.5mm thick magnets were used to perform vascular anastomoses in canines. In study one, eleven femoral arteries and veins were anastomosed creating fistulae in seven dogs. In study two, magnets were used to anastomose six interpositional vein grafts into the femoral arterial position in six dogs. In study three, the 1.5mm diameter saphenous artery feeding a 10cm × 8cm island musculocutaneous flap was transected and repaired using magnets in six dogs. In all studies, patency was confirmed under direct observation for at least one hour before closure. For the first two studies, patency was confirmed by Duplex Doppler ultrasound scans 6 and 13 weeks later. After explant, saline was perfused through all grafts and the hydrodynamic resistance was quantified. Results: All anastomoses were patent for the one hour of direct observation. All anastomoses in the shunt and graft models were patent for up to 14 weeks. The resistance after 14 weeks of implantation was not increased. Endothelialization of all blood-contacting surfaces was substantial. Conclusions: The magnets successfully created sutureless vascular anastomoses of three different types. Flaps were acutely successful. Approximation of non-vascular structures using this technology may be possible in the future.

Venous thromboembolism prophylaxis: patients at high risk to fail intermittent pneumatic compression

Objective To identify patients who fail intermittent pneumatic compression and who might be considered for other more intense thromboembolic prophylaxis. Methods We conducted a retrospective review of consecutive gynecologic surgery patients treated with intermittent pneumatic compression. Risk factors associated with thromboemboli and demographic data were reviewed. Clinical suspicion of thromboemboli was confirmed by established diagnostic techniques such as duplex Doppler ultrasound and ventilation perfusion scanning. The association between individual risk factors and the incidence of thromboemboli was identified. To control for confounding of variables, multivariable stepwise logistic regression analysis was performed. Results A total of 1862 patients undergoing gynecologic surgery between 1996 and 1997 were treated perioperatively with intermittent pneumatic compression. The overall incidence of postoperative thromboemboli was 1.3% (15 cases of clinically significant postoperative pulmonary emboli and nine deep venous thrombosis). Risk factors associated with the occurrence of thromboemboli were: cancer ( P = .001), history of deep venous thrombosis ( P = .03), hypertension ( P = .05), use of antihypertensives ( P = .04), and age at least 60 years ( P = .002). Intraoperative risk factors included duration of anesthesia more than 3 hours ( P = .05). The multivariable regression analysis found that the diagnosis of cancer ( P = .001), history of deep venous thrombosis ( P = .006), and age greater than 60 years ( P = .04) were independent prognostic factors. Patients with two or three of these variables had a 3.2% incidence of developing thromboemboli as compared with a 0.6% incidence of thromboemboli if the patient had none or one risk factor. Conclusion Patients most likely to fail intermittent pneumatic compression prophylaxis include those with cancer, a past history of deep venous thrombosis, or who are 60 years or older. This information identifies a “higher-risk” group of patients who should be considered for more intense prophylaxis programs.

Transcommissural valvuloplasty: Technique and results

Purpose: The purpose of this study was to describe the technique of a variation of closed external venous valve repair (transcommissural valvuloplasty), its complication rate, and duplex scan durability. Methods: The “blind” transcommissural valve repair of the vein was performed by placing transluminal sutures along the valve attachment lines, which simultaneously closed the valve attachment angle and also tightened the valve cusps. A total of 179 successfully repaired valve sites of 141 limbs in 129 patients were followed up 1 to 42 months through clinical observation and with duplex Doppler ultrasound scan. Results: Postoperative complications (< 30 days) occurred in 12 (9%) of 141 limbs: superficial (1) and deep (1) wound infection, large wound hematoma (4), seroma (1), and deep vein thrombosis (5), with associated pulmonary embolus in one patient. Seventy-eight percent (reflux time ≤ 0.5 seconds) and 81% (reflux time ≤ 1.0 seconds) of valve sites were competent. The cumulative competency rate at 30 months was 59% and 63%, respectively. The cumulative ulcer recurrence-free interval was 63% at 30 months (n = 92). The pain score and swelling grade substantially improved. Conclusion: Transcommissural valvuloplasty is a safe procedure with low morbidity. It is relatively rapid and simple to perform, and its competency rates are comparable to those of internal valvuloplasty. Advantages over the internal repair are that venotomy is not required, repair can be extended to small-caliber veins, and multiple valve stations can be repaired in a single stage. (J Vasc Surg 2000;32:969-76.)

Dorsal vein thrombosis of the penis presenting to an STD clinic.

To describe the clinical assessment, diagnosis and differential diagnosis of dorsal vein thrombosis of the penis (DVTP) and to observe its natural course over time. A descriptive study of six patients presenting with penile swelling to an STD clinic over a twenty month period. Six male patients between the ages of 22 and 46 years who self-presented to an STD clinic in Perth, Western Australia during a period from October 1991 to June 1993. Initial history, examination and follow up were undertaken as routine for all STD clinic patients. This was supplemented with later exhaustive history taking; full cardiovascular, fundoscopic, abdominal and genital examination; blood screening for coagulation defects, glucose level, autoantibodies, ESR, urea, electrolytes, calcium, creatinine and liver function test; and duplex doppler ultrasound scanning. No consistent abnormalities were detected on clinical examination, nor on blood testing. Ultrasound revealed one case of rupture of the corpus cavernosum, with haematoma and thrombus formation. There were two cases of pure DVTP demonstrable with ultrasound and two cases in which spontaneous resolution of clinical DVTP has occurred. The sixth patient declined further investigation and followup, but also displayed the clinical features of DVTP. Coagulation abnormalities as seen in elevated antithrombin III levels are of unknown significance. DVTP and ruptured corpus cavernosum should be considered in the differential diagnosis of gradual onset penile swelling and/or deformity. Its natural course tends to be one of spontaneous resolution. No sexual or urinary symptoms or dysfunction were experienced, even in the presence of persistent thrombus. Directed and specific investigation only, depending on the clinical state of the patient, should be carried out.

Color duplex Doppler ultrasound scanning for detection of deep venous thrombosis in total knee and hip arthroplasty patients: Incidence, location, and diagnostic accuracy compared with ascending venography

Ninety-nine patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) were prospectively studied for deep venous thrombosis (DVT) of the lower extremity. Eighty-three hips in 42 THA patients and 107 knees in 57 TKA patients were studied with noninvasive color duplex Doppler ultrasound flow scanning and ascending venography 3–9 days after surgery. In all patients, surveillance studies were performed within 24 hours. The ultrasonographer and radiologist were blinded to the study. The incidence of DVT was significantly greater following TKA (61%) than THA (17%) ( P < .001). After TKA, significantly more DVT was found in the ipsilateral (32 of 57 patients) versus contralateral knees (3 of 50 patients), and more thrombi were located below the knee (34 of 107 knees) than above the knee (1 of 107 knees) ( P < .001). More thrombi were found in the contralateral limb after THA (5 of 41 patients vs 3 of 42 patients), but this was not significant. Two patients developed nonfatal pulmonary emboli. The sensitivity of color flow scanning was relatively poor initially (67% of above-knee patients and 57% of below-knee patients), but improved in the last 50 patients (100% of above-knee patients and 79% of below-knee patients). Negative predictive values exceeded 90% in the THA group and 87% in the TKA group. Positive predictive values ranged from 89 to 100%. Specificity was always above 96%. Longitudinal ultrasound scanning with the newer Quantum 2000 angiodynograph (Issaquah, WA) provided the best image quality. Direct imaging of the thrombus and lack of augmentation was diagnostic of deep venous thrombosis as opposed to compressibility. Color duplex Doppler ultrasound flow scanning effectively predicts the presence of DVT in the above-knee segment in patients undergoing THA or TKA. The sensitivity in locating below-knee thrombi has significantly increased to 79% and appears to be technician-dependent.

Anatomic features of reduced-size liver transplant: postsurgical imaging characteristics.

In this retrospective review, the authors evaluated the anatomic and imaging features of 140 reduced-size liver transplants in 120 boys and girls; 100 of these patients (83.3%) were 2 years old or younger. The authors reviewed the surgical reports, plain radiographs, contrast material-enhanced studies of the gastrointestinal tract, duplex Doppler and color Doppler ultrasound (US) scans, and computed tomographic (CT) scans. Understanding the anatomic features associated with transplantation was crucial to understanding the post-surgical imaging characteristics. Changes in visceral anatomic structure caused a variety of imaging appearances, some of them misleading: (a) Some patients had unusual bowel gas patterns on plain radiographs because of a shift in location by bowel loops; (b) gastrointestinal studies showed gastric compression by an oversized left lobe that mimicked mass effect; and (c) displacement or migration of the duodenum, jejunum, or cecum into the right hepatic fossa sometimes mimicked malrotation. Pitfalls were created by fluid and gas collections at the transected edge. US and CT were often used to further assess anatomic structures after surgery; color Doppler was especially helpful in vascular localization.

Carotid Artery Reconstruction Following Extracorporeal Membrane Oxygenation

Right hemispheric brain injury has been noted in surviving infants treated with venoarterial extracorporeal membrane oxygenation (ECMO). This phenomenon may be secondary to permanent ligation of the right carotid artery. At our institution, conventional ventilatory therapy failed in five neonates with respiratory insufficiency, and they were treated successfully with ECMO. In four of the five neonates, the right carotid artery was reconstructed at the time of decannulation. At discharge, all newborns with carotid artery repair showed no signs of unilateral brain injury and had excellent antegrade flow in the right carotid artery as assessed by both duplex and transcranial Doppler ultrasound scanning. Carotid artery reconstruction after ECMO is a technically simple procedure that may reduce the incidence of right hemispheric brain injury and long-term consequences of marginal cerebral perfusion.

Duplex Doppler Ultrasound Scanning in Impotence: An Overview

Duplex Doppler Ultrasound Scanning in Impotence: An Overview

Duplex Doppler ultrasound in the diagnosis of cavernous transformation of the portal vein.

Duplex Doppler ultrasound scans were performed in 10 patients with proven cavernous transformation of the portal vein. All cases exhibited absence of the normal portal vein lumen with replacement by numerous tortuous vessels. Doppler studies revealed a characteristic "flat" waveform with a reduction in the time averaged velocity to less than 8 cm/s which is well below the normal range. The combination of real-time and Doppler ultrasound enabled an accurate diagnosis to be made in all cases.