A decision-analytic approach to obtain evidence-based vascular follow-up practices.
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Decision Support Techniques↗
Biomedical subjects
J M van Baalen
Publications and source records attributed to J M van Baalen.
Management of carotid body tumors.
The carotid body tumor is a rare neoplasm that has generated much literature over the past century, and for which continued controversy exists regarding natural history, biologic behavior, proper technique of excision, and the risk of morbidity and mortality. This article discusses overall management of carotid body tumors.
Aged↗
Nerve-preserving aortoiliac reconstruction surgery: anatomical study and surgical approach.
OBJECTIVE: Dysfunctional ejaculation and, to a lesser extent, dysfunctional erection caused by disruption of efferent sympathetic pathways is a common complication after aortoiliac reconstruction surgery. The aim was to give an anatomic motivation for a nerve-preserving approach on the basis of right-sided unilateral disruption of lumbar splanchnic nerves. METHODS: Anatomic and microscopic analysis of preaortic and para-aortic retroperitoneal regions in human cadavers was performed. Anatomic analysis was conducted of two aortoiliac reconstruction operations performed on human cadavers; one was performed according to a single-blind procedure, the second with a modified procedure. RESULTS: The lumbar splanchnic nerves supplying the superior hypogastric plexus from the right side were found to be less voluminous than the left-sided ones. The superior hypogastric plexus was found slightly shifted to the left of the midsagittal plane across the abdominal aorta and its bifurcation. Microscopic analysis revealed a thin fascia between the aorta and the subperitoneal tissue compartment. This fascia was used as a plain of dissection to mobilize the preaortic nerve-plexuses without damage from the aortic wall. Analysis of the specimens operated on showed a significant difference in nerve disruption. The standard procedure caused total disruption of the superior hypogastric plexus and extensive disruption of the inferior mesenteric plexus. The modified procedure only caused right-sided unilateral disruption of lumbar splanchnic nerves. CONCLUSION: The autonomic nerves supplying the bladder neck, the vas deferens, and the prostate are closely related to the abdominal aorta and its bifurcation. Right-sided unilateral disruption of lumbar splanchnic nerves without further damage to nervous structures would ensure at least one functional sympathetic pathway remaining after aortoiliac reconstruction surgery.
Aorta, Abdominal↗
Intraoperative renal duplex sonography: a valuable method for evaluating renal artery reconstructions.
OBJECTIVES: to determine the ability of duplex sonography to intraoperatively detect technical problems with renal artery reconstructions. DESIGN: retrospective evaluation of a standard protocol. PATIENTS AND METHODS: the outcome of intraoperative duplex was compared with postoperative angiography, surface duplex, MRA, echo or direct inspection in case of re-exploration in 77 renal artery reconstructions in 62 patients. These included six extracorporeal reconstructions, eight and 17 reconstructions with an artery and autogenous vein respectively, 10 renal artery re-implantations in the aorta (prosthesis), 32 endarterectomies and four reconstructions of kidney transplant vessels. RESULTS: intraoperative duplex was normal in 67/73 reconstructions with sufficient data. In six cases technical problems were revealed by intraoperative duplex and the reconstruction was re-explored. After re-exploration intraoperative duplex was normal in all cases. Confirmatory studies demonstrated normal results in 61/64 reconstructions with normal intraoperative duplex and abnormal results in 6/6 reconstructions with technical problems revealed by intraoperative duplex. Three reconstructions with normal intraoperative duplex occluded as demonstrated by angiography less than 2 weeks after surgery. CONCLUSIONS: renal duplex sonography is a valuable method available for intraoperative detection of technical problems. Haemodynamic duplex data were less important than B-mode imaging in discriminating between normal and abnormal reconstruction.
Adolescent↗
Thrombus within an aortic aneurysm does not reduce pressure on the aneurysmal wall.
PURPOSE: The role of thrombus within an aneurysm in relation to the risk of rupture is controversial. In literature, reports describing reduction and increase of rupture risk can be found. In the era of endovascular treatment of abdominal aortic aneurysms, a possible reduction of risk of rupture by the presence of thrombus within the aneurysmal sac can be important in relation to the location of an endoleak to the aneurysmal wall and in relation to the effect of the thrombosis of the endoleak, either spontaneously or by intervention. METHODS: In nine patients who underwent operation for an infrarenal aortic aneurysm by open procedure at the level of the thickest thrombus lining, the pressure within the aneurysmal thrombus (just inside the aneurysmal wall) was measured and compared with the systemic pressure. RESULTS: Pressure within systemic circulation and aneurysmal thrombus correlated well for the mean pressure (r = 0.90; P <.001) and for pulse pressure (r = 0.74; P <.01) Also, there was agreement between the levels of the mean pressure. Conduction of mean and pulse pressure to the aneurysmal wall was not related to the thickness of the thrombus at the level of the pressure measurement (r = 0.18 and r = 0.08, respectively). CONCLUSION: We conclude that thrombus within the aneurysm does not reduce both the mean and the pulse pressure near the aneurysmal wall and thus will not reduce the risk of rupture of the aneurysm.
Aged↗
Stent attachment site-related endoleakage after stent graft treatment: An in vitro study of the effects of graft size, stent type, and atherosclerotic wall changes.
OBJECTIVE: Perigraft endoleakage is a major complication of the endovascular treatment of abdominal aortic aneurysms. The factors that cause this form of endoleakage are not completely identified. The effect of sizing of the prosthesis in combination with either self-expandable or balloon-expandable stents is evaluated in this study. Further, the influence of atherosclerotic changes on endoleakage is evaluated. METHODS: Eight human abdominal aortas were assessed macroscopically at 11 sites for the presence of atherosclerotic changes with intravascular ultrasound scanning (IVUS) and with computed tomography (CT). Five aortas were placed in in vitro circulation with physiologic parameters. After the determination of the proximal and distal landing site of the stent graft, the diameter and surface measurements of the cross sections were taken. The stent graft diameters were chosen from 4-mm undersizing to 6-mm oversizing, both for Gianturco stent grafts (William Cook Europe A/S, Bjaeverskov, Denmark) and for Palmaz stent grafts (Cordis/Johnson & Johnston Co, Warren, NJ). After placement of the stent graft, the diameter and surface measurements of the aortic cross section were determined at the proximal and distal stent attachment sites. The presence and size of the folds at the stent attachment site and the interface with the aortic wall were determined with IVUS and angioscopy. Endoleakage was evaluated with angiography. After angioplasty of the stent attachment site, IVUS, angioscopy, and angiography were repeated. RESULTS: Regarding atherosclerotic changes of the aortic wall, the correlations between clinical impression and CT, clinical impression and IVUS, and CT and IVUS were high (r = 0.77, r = 0.79 and r = 0.79, respectively). For the Gianturco stent grafts, no significant relationship existed between the diameters measured before and after stent graft placement, leading to great differences in intended and achieved oversizing. The achieved oversizing was less in the case of minimal atherosclerotic changes of the aortic wall. The Gianturco stent graft followed the aortic wall closely during the heart cycle. The sizes of the folds of the fabric were clearly correlated with the achieved oversizing (r = 0.83; P =.04) and the grade of endoleakage (r = 0.88; P =.022). Angioplasty after stent graft placement had no effect on the diameter and the grade of endoleakage. Palmaz stent grafts did not follow the aortic wall during the heart cycle. A significant correlation existed between oversizing and both space between aortic wall and stent graft (r = -0.88; P =.02) and grade of endoleakage (r = 0.84; P =.036). Grade of endoleakage in the Palmaz stent graft group was less than in the Gianturco stent graft group. CONCLUSION: With the use of Gianturco stents, a great difference between intended and achieved oversizing is accomplished. The atherosclerotic changes of the aortic wall possibly affect this finding. The configuration of the Gianturco stent results in the formation of fold in the case of oversizing, which is associated with endoleakage. However, the self-expandable character of the stent leads to a close relation to the aortic wall during the heart cycle, and this may possibly accommodate future aortic neck dilation. The Palmaz stent grafts do not follow the aortic wall during the heart cycle, but they do lead to better interface between the graft and the aortic wall, which results in less endoleakage.
Angioscopy↗
Late endoleak after endovascular therapy for abdominal aortic aneurysm.
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Aorta, Abdominal↗
Abdominal aortic aneurysm measurements for endovascular repair: intra- and interobserver variability of CT measurements.
OBJECTIVES: to evaluate the intra- and interobserver variability in measurements of the aorta and iliac arteries in patients with abdominal aortic aneurysms (AAAs) considered for endovascular repair using computed tomography angiography (CTA). METHODS: the diameter of the neck, aneurysm, right and left iliac artery were measured by 5 observers in 10 consecutive patients. Measurements were performed on hard copy using a ruler and on a workstation using an electronic caliper. RESULTS: the intraobserver variability showed a decrease going from hard copy to workstation in the standard deviation of the differences of the paired observations for the neck from 3.54 mm to 1.18 mm; for the aorta from 4.16 to 1.72 mm; for the right iliac from 1.87 to 1.01 mm; for the left iliac from 2.07 to 0.87 mm. The interobserver variability showed a similar decrease for the neck in all ten pairs of observers; for the aorta in two, for the right iliac and left iliac in five. However, the difference between observers regularly exceeded 2 mm. CONCLUSION: the use of a workstation and electronic calipers results in lower intra- and interobserver variability. However, the results still show a clinically relevant difference between the observers. Therefore, it is necessary to develop an automatic observer-independent measurement technique.
Angiography↗
Operations that require supracoeliac aortic cross-clamping: perioperative monitoring with gastric tonometry.
OBJECTIVE: To assess the predictive value of a gastric intramucosal pH of less than 7.35 for mortality in surgical patients after supracoeliac aortic cross-clamping. DESIGN: Open prospective clinical study. SETTING: University hospital, The Netherlands. SUBJECTS: Six patients who required temporary supracoeliac, and four patients who required temporary infrarenal, cross-clamping of the aorta. MAIN OUTCOME MEASURES: Mortality and conventional measures of organ dysfunction correlated with gastric tonometry. RESULTS: All 6 patients who required supracoeliac cross-clamping underwent a steep, and 5 patients a prolonged, decrease in the gastric intramucosal pH. The mean lowest gastric intramucosal pH in the supracoeliac group was 7.05 and in the infrarenal group 7.28. All patients recovered completely. CONCLUSION: A pHig value below 7.35 does not seem to be a marker of mortality in patients who have undergone supracoeliac cross-clamping of the aorta.
APACHE↗
Endoleakage after stent-graft treatment of abdominal aneurysm: implications on pressure and imaging--an in vitro study.
BACKGROUND: Endoleakage is a fairly common problem after endovascular repair of abdominal aortic aneurysm and may prevent successful exclusion of the aneurysm. The consequences of endoleakage in terms of pressure in the aneurysmal sac are not exactly known. Moreover, the diagnosis of endoleakage is a problem because visualization of endoleaks can be difficult. METHOD: With an ex vivo model of circulation with an artificial aneurysm managed by means of a tube graft, studies were performed to evaluate precisely known diameters of endoleaks with both imaging techniques (computed tomography and digital subtraction angiography) and pressure measurements of the aneurysmal sac. The experiments were performed without endoleak (controls) and with 1.231-French (0.410 mm), 3-French (1 mm), and 7-French (2.33 mm) endoleaks. Pressure and imaging were evaluated in the absence and presence of a simulated open lumbar artery. The pressure in the prosthesis and in the aneurysmal sac were recorded simultaneously. Digital subtraction angiography with and without a Lucite acrylic plate, computed tomographic angiography, and delayed computed tomographic angiography were performed. For the first experiments, the aneurysmal sac was filled with starch solution. All tests were repeated with fresh thrombus in the aneurysmal sac. RESULTS: Each endoleak was associated with a diastolic pressure in the aneurysmal sac that was identical to diastolic systemic pressure, although the pressure curve was damped. At digital subtraction angiography without a Lucite acrylic plate, the 1.231-French (0.410 mm) endoleak was visualized without an open lumbar artery. When a Lucite acrylic plate was added, the endoleak was not visible until a lumbar artery was opened. In the presence of thrombus within the aneurysmal sac, all endoleaks were not visualized at digital subtraction angiography. At computed tomographic angiography, all endoleaks were not visualized in the absence of a thrombus mass in the aneurysmal sac. In the presence of thrombus within the aneurysmal sac, the 1.231-French (0.410 mm) endoleak became visible after opening of a simulated lumbar artery. At delayed computed tomographic angiography, all endoleaks were visualized without and with thrombus. CONCLUSION: Every endoleak, even a very small one, caused pressure greater than systemic diastolic pressure within the aneurysmal sac. However, small endoleaks were not visualized with digital subtraction angiography and computed tomographic angiography, whereas all endoleaks were visualized with a delayed computed tomographic angiography protocol. We believe that follow-up examinations after stent graft placement for aortic aneurysms should focus on pressure measurements, but until this is clinically feasible, delayed computed tomographic angiography should be performed.
Angiography, Digital Subtraction↗
Carotid recurrent stenosis and risk of ipsilateral stroke: a systematic review of the literature.
BACKGROUND: The main goal of follow-up after carotid endarterectomy is to prevent new strokes caused by recurrent stenosis. To determine the most cost-effective follow-up schedule, it is necessary to know the incidence of recurrent stenosis and the risk of stroke it carries. METHODS: A systematic review of the literature was performed using standard meta-analytical techniques. RESULTS: Incidence of recurrent stenosis: The data were very heterogeneous. The risk of recurrent stenosis was 10% in the first year, 3% in the second, and 2% in the third. Long-term risk of recurrent stenosis is about 1% per year. Risk of stroke: The reported relative risks of stroke in patients with recurrent stenosis compared with patients without recurrent stenosis showed extreme heterogeneity and ranged from 10 to 0.10. The random effects summary estimator of relative risk was 1.88. CONCLUSIONS: The data were very heterogeneous, and much better data are needed to arrive at truly reliable estimates of these important parameters of follow-up. It is clear, though, that the risk of recurrent stenosis is highest in the first few years after carotid endarterectomy and very low in later years. By use of general decision-analytic arguments, it can be argued that, given the test characteristics of carotid ultrasound, a small number of tests can be done in the first few years and that testing for restenosis should not be done after 4 years.
Aged↗
Vessel wall and flow characteristics after carotid endarterectomy: eversion endarterectomy compared with Dacron patch plasty.
OBJECTIVES: Experimental studies have demonstrated that decreases in vessel wall compliance and increases in turbulence may contribute to (re)stenosis. We studied vessel wall and flow characteristics after endarterectomy with Dacron patch plasty and after eversion endarterectomy, and compared those findings with the characteristics of non-stenotic, unoperated carotid arteries (controls). METHODS: Seventy-four patients who underwent 84 carotid endarterectomies were studied postoperatively by ultrasonography (2-24 months) Recorded variables included the diameter of the bulb, strain, elastic modulus (stiffness), and presence of turbulent flow. RESULTS: The vessel wall and flow characteristics of the two groups differed significantly. The diameter was higher and the strain lower in Dacron patch plasty than in controls; eversion endarterectomy did not differ from controls. The elastic modulus was higher (stiffer) in Dacron patch plasty than in eversion endarterectomy; neither Dacron patch plasty nor eversion endarterectomy differed significantly from controls. The stiffness index was not significantly different between the groups. Turbulence was present in Dacron patch plasty and eversion endarterectomy when compared with controls. CONCLUSION: In diameter, strain and stiffness, the operated carotid artery resembles the non-stenotic, unoperated artery more closely after eversion endarterectomy than after Dacron patch plasty.
Aged↗
Ruptured popliteal artery aneurysm. An insidious complication.
OBJECTIVES: To evaluate the incidence and clinical presentation of ruptured popliteal aneurysms. METHODS: The records of 89 consecutive patients, all males, seen between 1958 and 1995 with 124 arteriosclerotic popliteal aneurysms were reviewed retrospectively. Most aneurysms were symptomatic (69/124; 55.6%). In six cases (6/124; 4.8%) a rupture was present. RESULTS: There was a wide range in primary diagnosis varying from deep venous thrombosis to peroneal nerve palsy. In all cases primary reconstructive surgery was performed. No primary or secondary amputations were necessary. Surgical outcome was good in four cases. In the remaining cases one patient suffered from a permanent peroneal nerve palsy and one from non-disabling claudication. Review of the literature showed a rupture incidence of 2.5% (range 0-16%) and amputation rates as high as 100%. CONCLUSION: An acute rupture of a popliteal aneurysm is rare. Although the clinical presentation can be non-specific, this possibility must be especially taken into account when dealing with older male patients presenting with signs and symptoms of generalised atherosclerosis and non-specific pain in the popliteal region.
Acute Disease↗
Diagnosis and therapy of aortic prosthetic fistulas: trends over a 30-year experience.
A retrospective study was carried out of patients from a single institution over a 30-year period. Thirty-one patients presented with 33 fistulas, four non-enteric and 27 enteric. In 25 of 27 patients with a prosthesis-related enteric fistula gastrointestinal bleeding was present. Angiography revealed the fistula in five patients endoscopy in three, and barium studies, echography and computed tomography each revealed one fistula. Six patients died before and five died during operation. In 20 patients various techniques were used for treatment. In-hospital mortality decreased from six of eight patients before 1970, to seven of ten between 1971 and 1980, and to four of 13 after 1981. In the long term, patients treated with an extra-anatomic reconstruction had a poorer prognosis than those treated by in situ reconstruction. This experience shows that diagnostic tests often fail to reveal a prosthesis-related fistula and that mortality can be substantially reduced by early exploration in patients with negative diagnostic studies.
Adolescent↗
Pitfalls in the diagnosis of origin stenosis of the coeliac and superior mesenteric arteries with transabdominal color duplex examination.
The purpose of this study is to evaluate the effects of respiration, localization of the Doppler sample, and the presence of origin stenosis on the Doppler parameters of coeliac and superior mesenteric arteries in 22 patients undergoing elective abdominal vascular reconstructive surgery under standardized stable anesthesia. Deep inspiration decreased peak systolic and end diastolic velocities of the coeliac artery origin. Proximal to distal Doppler velocities of normal coeliac and superior mesenteric artery origins were comparable. However, in the presence of an origin stenosis, the increase of Doppler velocities at the origin of the coeliac and superior mesenteric arteries is likely to be missed by transabdominal scanning.
Adult↗
Asymptomatic popliteal aneurysm: elective operation versus conservative follow-up.
In a retrospective study 42 patients with asymptomatic popliteal artery aneurysm were followed without surgery to identify variables predicting the risk of complications. The mean aneurysm size was 3.1 cm. Abnormal ankle pulses were found in 18 of the 42 limbs in which an asymptomatic popliteal aneurysm was present. Follow-up was complete (mean 6.2 years). Twenty-five patients developed complications at a mean observation time of 18 months. As a result three lost the limb, eight had claudication, two needed a fasciotomy and one had a peroneal nerve palsy. The cumulative risk of developing complications during follow-up was 24 per cent at 1 year, rising to 68 per cent at 5 years. Patients with absent ankle pulses and those already operated on for abdominal aortic aneurysm proved to be especially at risk. Patient survival appeared to be normal for the period of observation. It is concluded that asymptomatic aneurysm of the popliteal artery is a potentially dangerous lesion that may justify elective surgery; it is possible to select those at highest risk.
Aged↗
Thoracic origin of right renal artery.
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Adult↗
Doppler ultrasound diagnosis of complications of polytetrafluoroethylene (PTFE) graft shunts.
Doppler spectral analysis of PIFE graft shunts for haemodialysis was carried out in 20 patients. All shunts were functioning satisfactorily. One patient had severe oedema of the forearm and hand. In four of the 20 patients, stenosis of the venous anastomosis was diagnosed by Doppler examination. Retrograde venous flow in the ulnar vein at the wrist was seen in the patient with severe oedema. All patients underwent angiography and the diagnosis of stenosis and retrograde flow was confirmed. Graft arteriography has proved useful in detecting shunt lesions, but may be hazardous at the access site and for the patient. Doppler investigation in noninvasive and can detect shunt complications early and with great accuracy.
Adult↗