https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(97)09508-1.pdf

Randomised comparison of primary stent placement versus primary angioplasty followed by selective stent placement in patients with iliac-artery occlusive disease

We compared ultrasonic duplex scanning and angiography for the localization and classification of arterial stenoses and occlusions in 32 patients. The criteria for the detection of a greater than 50% diameter reducing stenosis was an increase in peak systolic velocity of greater than 100%, loss of reverse flow, and spectral broadening. Duplex studies and angiograms were evaluated in a blinded fashion. The agreement between duplex scanning and angiography for the 383 arterial segments studied was not significantly different than the previously reported agreement between two different radiologists reading the same angiograms (kappa of 0.55 vs 0.63). For detecting stenoses that were greater than 50% diameter reducing by angiography, duplex scanning had a sensitivity of 82%, a specificity of 92%, a positive predictive value of 80%, and a negative predictive value of 93%. These results are as good as previously reported comparisons between two different radiologists' readings of the same angiograms.

Duplex scanning for diagnosis of aortoiliac and femoropopliteal disease: a prospective study.

Background.

The purpose of this study was to analyze the causes of flap compromise and failure in head and neck free flap reconstruction.



Methods.

We retrospectively reviewed 1310 free flap reconstructions for head and neck defects performed between July 1995 and June 2006.



Results.

Forty-nine cases of flap compromise due to vascular obstruction (3.7%) were identified, and 27 flaps were lost (2%). Arterial occlusions occurred in 12 flaps, with a salvage rate of 33%. Eight flaps failed within the first 24 hours, and only 1 of these was salvageable. Five of the 8 flaps had intraoperative thrombosis due to technical difficulties. Venous occlusions occurred in 31 flaps, with a salvage rate of 58%. Twenty-two venous occlusions occurred within the first 72 hours. The main reason for venous failure was mechanical obstruction due to compression, twisting, kinking, or stretching of the vein. The most common cause of late failures (after 7 days) was unrecognized failure of a buried flap owing to the lack of reliable monitoring. Overall, there was no correlation between surgeon experience and flap failure, but the flap failure rate was lower in surgeons who had performed more than 70 free flap procedures.



Conclusion.

Precise surgical techniques, avoidance of mechanical obstruction, and better monitoring of buried flaps may further improve the success rate of free tissue transfer in complex head and neck reconstruction. © 2008 Wiley Periodicals, Inc. Head Neck, 2009

https://onlinelibrary.wiley.com/doi/pdf/10.1002/hed.20927

Analysis of 49 cases of flap compromise in 1310 free flaps for head and neck reconstruction.

The prevalence of carotid and lower extremity arterial disease was assessed in a healthy population of 56 elderly adults with isolated systolic hypertension. Duplex scans were performed to determine the extent of carotid disease, and postexercise ratios of ankle to arm systolic blood pressure were measured to assess lower extremity arterial disease. Internal carotid stenosis was found in 38% (21 of 56) of subjects and lower extremity arterial disease in 42% (23 of 55). The strongest predictor of internal carotid stenosis was lower extremity arterial disease. Independent risk factors for lower extremity arterial disease were smoking, internal carotid stenosis, and age. A measure of extent of carotid plaque was found to correlate with age, carotid stenosis, male sex, history of smoking, and total cholesterol. The high prevalence of peripheral vascular disease in this population may be related to their age and blood pressure. The high correlation between carotid stenosis and lower extremity arterial disease suggests that persons with peripheral vascular disease should be assessed and treated for atherosclerotic disease in general.

https://www.ahajournals.org/doi/pdf/10.1161/01.STR.18.5.817

Carotid and lower extremity arterial disease in elderly adults with isolated systolic hypertension.

A review is given of quantitative techniques and clinical applications of arterial Doppler ultrasound. The currently available Doppler equipment of stand-alone continuous wave and pulsed wave units, duplex systems and colour flow systems is briefly described. Doppler ultrasound can be divided into procedures concerned with waveform analysis, volume flow measurement and more recently colour flow imaging. Arterial Doppler waveform analysis is considered for a number of areas including carotid, lower limb, renal and renal transplant, obstetrics, adult cerebral, neonatal cerebral, and tumour studies. Using a duplex scanner volume flow in arteries can be measured from estimates of vessel cross sectional area, mean Doppler frequency and beam-vessel angle. The errors associated with each of these measurements is discussed, and reports of experimentally determined in vivo accuracy of volume flow measurements made using this technique are considered. Other volume flow measurement techniques including the promising attenuation compensation method are also explored.

https://iopscience.iop.org/article/10.1088/0143-0815/11/1/001/pdf

Measurement of arterial blood flow by Doppler ultrasound

In a clinical study, 78 carotid bifurcations were examined by pulsed Doppler ultrasonography and X-ray arteriography. Maximum Doppler frequencies greater than or equal to 3 kHz diagnosed stenoses of greater than or equal to 25% diameter reduction with a sensitivity of 73% and specificity of 79%. A quantitative analysis of the degree of spectral broadening was obtained from the ratio of the maximum to mean frequency at peak systole and improved the sensitivity and specificity to 90% and 98% respectively. All vessels greater than 40% stenosis were correctly classified as stenosed and all less than 20% stenosis were classified as normal.

Ultrasonic doppler spectral broadening in the diagnosis of internal carotid artery stenosis.

We examined the internal jugular veins in three groups of patients who had undergone (1) a functional neck dissection and radiotherapy, (2) a functional neck dissection alone, or (3) radiotherapy alone, using a noninvasive color Doppler ultrasound scan. The internal jugular veins were ultrasonically bilaterally normal in 18% of patients who had undergone a functional neck dissection and radiotherapy, in 88% of patients who had undergone a functional neck dissection alone, and in 57% of patients who had undergone radiotherapy alone. The combination of a functional neck dissection and radiotherapy significantly affected the internal jugular vein when compared with a functional neck dissection alone.

Relative effect of surgery and radiotherapy on the internal jugular vein following functional neck dissection.

One hundred and ninety-five consecutive referrals to the vascular laboratory for carotid artery investigation have been studied. Carotid bruits were assessed by the referring clinician and documented. All patients underwent bilateral imaging and spectrum analysis of the extra-cranial carotid vessels using a pulsed Doppler ultrasound technique. Eighty-two were further assessed by X-ray contrast angiography. Of 390 internal carotids examined by ultrasound, 65 exhibited intraluminal turbulence of which 49 (75 per cent) had a bruit. In 62 (56 per cent) of 111 internal carotids in the series which were said to have a bruit on clinical examination, no turbulence was found; in 15 instances the external carotid vessel was shown as the true source of turbulence and in the remainder the bruits may have been transmitted from the heart. One hundred and fifty-six vessels were assessed by X-ray and 55 shown to have significant stenosis; 38 (69 per cent) of these exhibited a bruit. Bruit was often absent at high degrees of stenosis and in occluded vessels. Although a carotid bruit is often a marker of internal carotid intraluminal turbulence and stenosis, this is by no means always so. Cervical bruit may also be due to a diseased external carotid or to sounds transmitted from a more proximal source. Conversely, absence of bruit is a feature not only of normal vessels but of many arteries which are stenosed (especially if this is of high degree) or occluded.

Carotid artery bruit: Association with internal carotid stenosis and intraluminal turbulence

Fourteen patients with symptomatic atheromatous stenoses of common or external iliac arteries underwent percutaneous arterial dilatation. Twelve procedures were considered successful in terms of arteriographic and symptomatic improvement but the application of three haemodynamic indices (pressure index, pulsatility index and the papavarine test) indicated that only 8 patients had gained a significant improvement in blood flow. These results illustrate the need for quantitative measurements in the assessment of this new technique.

Haemodynamic assessment following iliac artery dilatation.

One hundred carotid arteries in 53 patients suffering from transient cerebral ischaemia or amaurosis fugax have been studied prospectively. Internal carotid arteries were assessed by a six-channel pulsed Doppler imaging system combined with Doppler spectrum analysis and the findings compared with those obtained by X-ray contrast arteriography. Stenosis (greater than 25% diameter reduction) was correctly diagnosed by ultrasonography with a sensitivity of 93% and a specificity of 96%. Occlusion was correctly diagnosed with a sensitivity of 92% and a specificity of 97%. The ability to recognize arterial stenosis and occlusion with this noninvasive system suggests that it has a major part to play in screening patients with suspected carotid artery disease.

C.D. Sheldon

Papers

Ultrasonic doppler spectral broadening in the diagnosis of internal carotid artery stenosis.

Relative effect of surgery and radiotherapy on the internal jugular vein following functional neck dissection.

Carotid artery bruit: Association with internal carotid stenosis and intraluminal turbulence

Haemodynamic assessment following iliac artery dilatation.

Pulsed Doppler imaging and spectrum analysis for detection of carotid artery disease.