• Cerebrovascular Evaluation (CVE)
• Lower/Upper Extremity Venous Evaluation (LEV), (UEV)
• Lower/Upper Extremity Arterial Evaluation (LEA), (UEA)
• Abdominal Duplex Exams:
• Renal Vascular Evaluation
• Mesenteric Vascular Evaluation
• Hepato-Portal Evaluation
• Other Exams:
• AAA
• Air Plethysmography
• TcpO2
• Vein mapping
• TOS
• Transcranial Doppler Examination for Cerebral Vasospasm
• Raynaud's Syndrome Examination
• Dialysis Access
• Within the OR:
• Intraoperative duplex exams
• Closure procedure
• Transcranial monitoring

This study includes extensive evaluation of the cerebrovascular circulation from the subclavian artery to the intracranial cerebral arteries. The comprehensive nature of this study enables Pacific Vascular to maintain very high accuracy.

Clinical Indications:

• Symptoms of TIA: Unilateral weakness, numbness, tingling, speech difficulties, Stroke with recovery
• Amaurosis Fugax
• Symptoms of Vertebrobasilar Insufficiency: Dizziness, Imbalance, Loss of Consciousness, Confusion, Headache
• Aysmptomatic bruit
• Pre-op high risk
• Follow-up known ICA stenosis
• Pulsatile neck masses

Duplex/color scanning and continuous wave Doppler ultrasound are utilized to detect and quantify obstructions of the carotid, vertebral, and subclavian arteries. Internal carotid artery stenosis is reported in terms of diameter reduction as a percent stenosis. The vertebral and subclavian arteries are evaluated for obstructions and subclavian steal phenomenon. Evaluation for plaque ulceration and hemorrhage (where image quality permits), intimal dissection/flaps, aneurysm, carotid body tumor, fibromuscular dysplasia, kinking, and re-stenosis following carotid endarterectomy is also performed whenever possible.

Transcranial Doppler is utilized to evaluate the major basal cerebral arteries for intracranial stenosis and occlusions, assess collateral flow patterns, identify arteriovenous malformations, cerebral emboli, mechanical compression of the vertebral arteries, and cerebral vasospasm in patients with subarachnoid hemorrhage.

Abbreviated and Limited Carotid Examinations

Abbreviated Cerebrovascular Evaluation - frequently ordered as a follow-up exam for patients with a known carotid lesion(s). Duplex color scanning and continuous wave Doppler ultrasound and duplex/color scanning are utilized to evaluate bilateral cervical carotids.

Limited Cerebrovascular Evaluation - includes duplex/scanning and continuous wave Doppler ultrasound and duplex/scanning of the surgical carotid bifurcation only. Generally ordered shortly following a carotid endarterectomy.

Patients are referred for a Lower Extremity Venous Evaluation for suspected acute deep vein thrombosis (DVT) and/or superficial vein thrombosis, chronic venous insufficiency (chronic venous obstruction and/or valvular incompetence). Patients are also seen for follow-up evaluations of a known DVT to document progressesion or resolution of the thrombotic process.

Clinical Indications:

• Limb pain, swelling, or tenderness
• Limb cyanosis and/or erythema
• Abnormal VQ scan
• Symptoms of pulmonary embolus
  • Shortness of breath
  • Chest pain
  • Dyspnea
  • Hemoptysis
  • Respiratory distress
  • Low-grade Fever of unknown origin
• Varicosities Induration
• Hyperpigmentation
• Alceration

Duplex/color scanning is utilized to evaluate the abdominal and pelvic veins and the deep and superficial veins of the lower extremities for obstruction and valvular incompetence. Routinely examined are the inferior vena cava, common and external iliac veins, common and superficial femoral veins, popliteal veins, common tibioperoneal trunk veins, the posterior tibial and peroneal veins, and the greater saphenous veins. The anterior tibial, gastrocnemius, and lesser saphenous veins, and the soleal sinuses are evaluated when clinically indicated and/or feasible. Examinations are performed bilaterally unless the patient presents with unilateral symptoms, has no significant risk factors, and/or a unilateral examination is specifically requested.

Upper Extremity Venous Evaluations are typically ordered when a patient presents with acute pain and/or swelling and sometimes discoloration often at or around a PICC line site or following injury or other trauma to the upper limb. Symptoms and risk factors are similar to that of the Lower Extremity Venous evaluation.

Clinical indications include:

• Limb pain
• Swelling
• Tenderness or suspected pulmonary embolus

Duplex/Color scanning is utilized to investigate the distal innominate, internal jugular, subclavian, axillary, brachial, basilic, and cephalic veins, and the radial and ulnar veins selectively. Examinations are performed bilaterally unless otherwise requested

Lower Extremity Arterial Evaluation is an excellent diagnostic tool that accurately reports the extent of arterial insufficiency or occlusive disease and localizes and quantifies stenoses within the lower extremities utilizing a noninvasive approach. The presence, size and location of aneurysms and pseudoaneurysms can also be identified using this exam. Particularly helpful is the ability to non-invasively differentiate true claudication from pseudoclaudication (e.g., leg pain of non-vascular etiology).

Clinical Indications:

• Chronic arterial occlusive disease
• Symptoms of Claudication - calf, thigh and/or hip pain with walking or exercise that resolves with short rest
• Symptoms of Rest pain
• Ulceration
• Gangrene
• Acute arterial occlusion: pain, pallor, pulselessness , parasthesias, paralysis, and polar
• Aneurysm
• Pseudoaneurysm
• Follow-up post PTA/stenting
• Follow-up post bypass grafting

Routine testing involves measurements of resting ankle-brachial indices followed by measurements after treadmill exercise (unless contraindicated by the patients cardiac status or mobility). If ankle pressures are abnormal, either at rest and/or following exercise, duplex scanning is performed to determine the location and severity of arterial lesions. Specific arteries examined include the abdominal aorta, common and external iliac arteries, common and superficial femoral arteries, and popliteal arteries. The anterior and posterior tibial, and peroneal arteries are examined when indicated.

Photoplethysmography and measurement of toe pressures are performed selectively in patients with diabetes and resultant medial calcinosis of the arteries (wherein ankle pressure are erroneous), as well as with patients for whom small vessel disease is of concern. All examinations are performed bilaterally unless otherwise specifically requested.

Upper Extremity Arterial Evaluations are routinely ordered to detect upper extremity arterial ischemia related to atherosclerotic disease, thoracic outlet phenomenon, and Raynaud's phenomenon. Measurements of upper extremity segmental pressures (arm and forearm), with selective photoplethysmographic evaluation of digit blood flow and measurement of digit pressures are taken. Continuous wave Doppler ultrasound of the subclavian, axillary, brachial, ulnar, and radial arteries is performed to evaluate potential arterial lesions. "Modified Allen testing" is performed to assess the completeness of the palmar arches. Duplex/color scanning is performed selectively when indicated.

All studies are performed bilaterally unless otherwise requested.

Renal Vascular Evaluation

Hypertension affects over 20% of the adult population. Renovascular disorders are among the rare secondary causes of hypertension and include renal arterial lesions from either atheroma or fibromuscular dysplasia. Other findings in the renal vascular exam include intrinsic renal parenchymal disease, mesenteric stenosis or extrensic compression, and aneurysm.

Clinical Indications:

• Hypertension (new onset or uncontrollable)
• Follow-up post PTA/stenting
• Follow-up bypass grafting
• Follow-up renal allograft

Duplex/color scanning is utilized to evaluate renal artery and kidney parenchymal blood flow for hemodynamically significant renal artery stenosis (greater than 60%) and occlusions. Changes in renovascular resistance within the kidney parenchyma associated with the presence of intrinsic renal parenchymal disease are evaluated, and information regarding kidney size and related structural abnormalities is also provided. Examination of the abdominal aorta and the origins of the celiac and superior mesenteric arteries are routinely included.

Renal allografts are evaluated for acute renal transplant rejection, acute tubular necrosis, renal artery stenosis, renal vein thrombosis, arteriovenous fistula, perinephric fluid accumulations and hydronephrosis

Mesenteric Vascular Evaluation

Of the three intra-abdominal branches supplying the majority of flow to the gastrointestinal organs, an acute obstruction has a very dramatic clinical presentation and requires immediate measures with elevated patient risk. A less severe chronic flow restriction allows for the development of collateral vessels, yet may result in the more intermittent symptoms seen below.

Clinical Indications:

• Abdominal pain associated with eating
• Fear of food
• Chronic diarrhea
• Unexplained weight loss

Duplex/color scanning is utilized to evaluate the celiac, superior mesenteric, and inferior mesenteric arteries for hemodynamically significant stenosis (> 70%) and occlusions. Celiac artery compression by the arcuate ligament can also be diagnosed. The abdominal aorta and the hepatic and splenic arteries are also examined.

Hepato-Portal Evaluation

Often, patients with suspected pathology within the liver have other disease processes at work and may present with complicated symptoms. Pacific Vascular evaluates the vasculature that feeds and drains the liver, determines the direction of the portal vein flow (whether hepatopetal or hepatofugal), and identifies portal vein thrombosis, hepatic vein thrombosis, and patency and status of porto-systemic shunts and TIPS (transjugular intrahepatic portosystemic shunts).

Clinical indications

• Suspected portal hypertension with esophageal/bleeding varices
• Abdominal pain
• Abdominal distention
• Ascites
• Hepatic encephalopathy
• Venous hum
• Cruveilhier-Baumgarten Syndrome
• Budd-Chiari Syndrome with sudden abdominal epigastric pain with nausea and vomiting
• Hepatomegaly
• Splenomegaly
• Abdominal collateral vein distention
• Follow-up post porto-systemic shunting (including TIPS- transjugular intrahepatic portosystemic shunting).

Duplex/color scanning is utilized to examine the inferior vena cava, left and right renal veins, splenic vein (as well as the spleen), portal vein (main, left, and right), hepatic vein (left, middle, and right), and the hepatic artery. Specific objectives include assessment of flow quality and direction to assist in diagnosis of portal hypertension, identification of portal vein and/or hepatic vein thrombosis, and evaluation of flow quality and direction in patients with porto-systemic shunts.

The technical quality of all abdominal vascular studies is significantly affected by patient body habitus and presence of abdominal gas. Ideally, patients should have no food or drink (except water and medications) 8 hours prior to testing. Diabetic patients should eat and take medications per usual.

AAA - The abdominal aorta is scanned from the midline to determine the presence or absence of an aneurysm. An aneurysm is a dilated segment of the aorta with a cross-sectional diameter measuring greater than 3 centimeters. This study can determine whether an aneurysim is infrarenal or suprarenal and if there is any thrombus or heterogenous plaque features within the dilated lumen.

Air Plethysmography - Air plethysmography (APG), which quantitatively assesses the effects of chronic venous insufficiency on lower extremity venous physiology is available upon request at limited locations. APG testing measures changes in venous outflow, venous reflux, calf muscle pump function, and ambulatory venous pressure resulting from chronic venous insufficiency.

TcpO2 - Transcutaneous oxygen pressure testing evaluates oxygen delivery to tissue, and aids in determining potential success of wound healing, or indication for tissue transfer or revascularization (e.g., bypass grafting) procedure.

To perform a Tcp02 evaluation, the patient remains in the supine position. Small electrodes are placed on standard sites on the chest, below the knee, and two over the dorsum of the foot. An index of the central chest measurement to a regional limb value or a Regional Perfusion Index also contributes to the determination of likelihood of healing.

Vein mapping - The greater saphenous vein is often used for coronary or peripheral arterial bypass graft surgery. A diameter of 0.3 cm or 3 mm is typically the best vein caliber for these surgeries. The saphenous vein is imaged then marked and mapped on the skin surface. Periodic diameter measurements as well as venous flow samples are taken and reported to the surgeon. The surgeon notifies the technologist of the type of surgical procedure and specifies which limbs are to be mapped and/or marked.

TOS - Pacific Vascular is often called upon to evaluate changes in arterial blood flow associated with positional changes of the upper extremity related to thoracic outlet syndrome. This syndrome is often suspected in patients with shoulder/arm complaints resulting from occupational repetitive motion traumas, motor vehicle accidents, shoulder or low neck trauma. Although symptoms attributable to this syndrome can occur as a result of arterial compression, it is quite clear that most symptoms are neurogenic in nature due to brachial plexus nerve compression.

Clinical Indications:

• Shoulder/arm numbness and tingling
• Pain
• Fatigue
• Clumsiness
• Weakness
• Headache

Continuous wave Doppler is used to take segmental pressures of the upper extremities in order to rule out focal organic obstruction of the arterial circulation. Photoplethysmography (PPG) at the level of the digits is used to rule out small vessel obstruction by the presence of "fixed" lesions that might result in arterial compromise and provocation of symptoms. With PPG sensors on the digits, changes are noted related to arm elevation maneuvers (i.e. Hyperabduction extension, Adson maneuver, costoclavicular modified military maneuver, and the 90 degree abduction/external rotation maneuver). Patients may also be given an EAST test (elevated arm stress test) to provide additional information for determining the level of contribution.

The primary purpose of this exam is to provide relevant clinical information, rule out vascular phenomena mimicking TOS, and provide clinical correlates in those situations where arterial compression can be demonstrated with the appropriate symptoms.

Transcranial Doppler Examination for Cerebral Vasospasm - It is well documented that intracranial cerebral arterial vasospasm can potentially cause significant neurological deterioration and deficits and even infarction following an intracranial trauma, subarachnoid hemorrhage or surgery (such as aneurysm clipping). Patients are at an increased risk for developing vasospasm typically one to two weeks following the initial events. TCD is a simple and effective tool for identifying and monitoring patients who may or have developed vasospasm and assessing the severity of the vasospastic response. Ideally patients are given a baseline exam as soon as possible following the bleed or surgery. They are then evaluated on a serial basis during the high-risk phase. The peak end and mean velocities are measured. A velocity ratio of the middle cerebral artery to the cervical internal carotid artery is also used to identify vasospasm and the level of severity.

Raynaud's Syndrome Examination - Raynaud's syndrome is defined as episodic digital pallor, cyanosis, or both accompanied by moderate to severe discomfort caused by cold exposure, emotional stress or chronic repetitive trauma to the hand/foot and/or digits. It is believed that the cause is due to an underlying vasospastic condition.

Clinical indications:

• Digital color changes
• Hand or foot numbness, tingling, pain, and throbbing/burning sensations
• Often the onset is related to cold exposure and/or emotional stress

Predisposing risk factors to Raynaud's include occupational trauma (repetitive stress to the hand/foot//digits such as when operating a jack hammer), cold injury (frostbite), scleroderma, Rheumatoid Arthritis, Lupus and Berger's Disease.

A physical exam in our laboratory identifies any diminished wrist or foot pulses or the presence of supraclavicular or femoral bruits. Next, the extremity arterial systems are evaluated segmental pressures including digital measurements with photoplethysmography and spectral analysis. Digital pressures and photoplethysmography are then used to evaluate the digits of the affected limbs in room temperature, ice water immersion, and warm water immersion.

Dialysis Access - With over 100,000 patients on chronic hemodialysis, duplex ultrasonography is often called upon to evaluate patients with dialysis access sites for potential defects and complications prior to graft failure from thrombosis.

Clinical indications include:

• Change in the bruit or thrill of the graft
• Prolonged dialysis times
• Elevated venous pressure found during dialysis
• Difficult needle placement for dialysis
• Abnormal lab values
• Arm swelling, and digital pain, numbness or tingling

The dialysis "system" is evaluated in its entirety with duplex ultrasonography and Doppler spectrum analysis. This includes the inflow through the subclavian, axillary, and brachial arteries and the outflow of the access site, throughout the venous system and back up to the neck. Graft failure from thrombosis is often secondary to fibrointimal hyperplasia at the graft to venous anastamosis. Other complications may include perigraft fluid collections, hematoma, pseudoaneurysm, and aneurysm.

Intraoperative duplex exams - The intraoperative duplex is performed on both lower extremity bypass grafts and carotid endarterectomy sites by the vascular surgeon who manipulates the ultrasound scan-head within the sterile surgical wound directly on the vessel or graft. A certain degree of technical expertise and knowledge of duplex interpretive criteria are needed. The vascular technologist controls the ultrasound equipment from outside the sterile field. Sterility is achieved by covering the probe with a sterile sheath. Duplex has been shown to be safe and accurate. It is especially helpful in identifying "high risk" reconstructions that call for careful intraoperative assessment of technical precision, and those that may benefit from more frequent post-op surveillance.

Closure procedure - this procedure is performed for patients with superficial venous reflux. It procedure uses a special system of radio frequency energy to heat a catheter that is inserted into the greater saphenous vein. Exposure to intense heat causes the vein wall to collapse and seal shut. The vascular technologist uses the ultrasound system to guide the surgeon placing the catheter into the vein, and to confirm that flow has terminated after the treatment is finished.

Transcranial monitoring - The ipsilateral middle cerebral artery is monitored during carotid endarterectomy for the presence of cerebral emboli and to help determine if a shunt is necessary during the procedure. Once the patient is admitted to the hospital, a pre-op evaluation is done to find the appropriate transcranial "window" and apply the headgear which holds the Doppler probe in place during surgery. The patient's intracranial blood flow is monitored closely to identify and count any embolic signatures that may occur during the dissection, endarterectomy, and closing phase, as well as in the recovery room.