Isotope angiography: technique, validation and value in the assessment of arterial reconstruction.

Isotope angiography performed by intravenous injection of technetium 99m pertechnetate has been demonstrated to be of value in the diagnosis and management of a variety of disorders of the large arteries. An improved technique of isotope angiography is described and the technique validated (53 cases) in normal and diseased arteries by correlating it with conventional contrast arteriography and/or operative findings. Peripheral arteries as far distal as the wrist or mid-calf have been accurately visualized and quantitation of isotope arrival times and total isotope activity in different parts of the arterial tree has provided a means of evaluating the hemodynamic significance of stenosing lesions. Thirty-nine arterial reconstructions were studied by this technique. Seven of 27 (26%) clinically patent arterial reconstructions were found to be harboring significant and potentially dangerous imperfections which were clinically unsuspected. Nine of 12 (75%) arterial reconstructions thought clinically to be occluded were demonstrated to be patent, obviating the need for invasive contrast arteriography. Isotope angiography may be used with no risk for the immediate postoperative and long-term evaluation of arterial reconstructions. Only those patients with abnormalities identified on isotope angiography need have conventional contrast arteriography for further delineation of the abnormality so that it may be repaired before it causes failure of the reconstruction.     

Current Technique of the Arterial Switch Procedure for Transposition of the Great Arteries

The arterial switch operation has recently become the preferred method of repair for patients with transposition of the great arteries in the majority of congenital heart centers. Concern regarding the late results in those patients undergoing atrial repairs has stimulated this major change in operative treatment. Although initially high, the current operative mortality has been reduced substantially to equal that of atrial repair in experienced institutions. The precise methods of coronary artery transfer, as well as aortic and pulmonary artery reconstruction have been refined to allow the routine performance of direct arterial repair within the first few weeks of life with low risk and excellent late survival. At the University of Michigan, a policy of arterial repair for all suitable infants with transposition of the great arteries with or without ventricular septal defect was adopted in July 1985. Although modifications in surgical technique have been made, the basic procedure has remained constant. This article reviews the current operative approach used in a consecutive series of 81 patients undergoing the arterial switch procedure.     

动静脉穿刺网络课件的开发及其应用

目的:确保护理教学效果,提高教学水平。方法:应用多项信息技术将动静脉穿刺技术制作成教学网络课件,并用于临床教学。结果:该课件在本校园网上运行半年余,2000余人次对其进行访问,受到师生好评。结论:该课件能及时反映动静脉穿刺的最新研究进展及具体操作步骤和使用方法,实现护理教学的直观性和交互性,对护理教学和临床带教指导有一定的借鉴作用。     

New approach to the splenic vessels

The transperitoneal approach is used systematically for an arterial or a venous splenorenal anastomosis. However, this approach is associated with high morbidity and mortality rates. Because of our anatomical and surgical findings we have used the retroperitoneal approach to the splenic hilus by means of the lumbar region. The first splenorenal arterial anastomosis with this approach was done in 1972. The approach has proved to be less aggressive since it avoids the danger of damaging the pancreas, it is a more direct approach to the splenic vessels and it provides better exposure and facilitates the anastomosis. In addition, the loss or infection of ascitic fluid in cirrhotic patients is avoided with this approach, as well as intraoperative hemorrhaging caused by the great surplus circulation. There has been neither mortality nor complications in the 13 cases of arterial and venous splenorenal anastomoses that we have done with this method.     

Sodium nitroprusside and coronary surgery

The anti-hypertensive properties of sodium nitroprusside have been tested in 20 patients undergoing coronary arterial surgery. Were measured the arterial pressure, heart rate, mean right atrial pressure and mean left atrial pressure. The cardiac output, systemic vascular resistance and left ventricular stroke work index were deduced. A dose of 0.8 to 3 micrograms . kg-1 . min-1 sodium nitroprusside was given at the start of surgery, and immediately afterwards. The results showed a decrease of the systemic vascular resistance, a significant drop of arterial pressure, and a significant increase of heart rate as well as a tendency for the cardiac output to fall, probably because of insufficient vascular filing. When the mean left atrial pressure was kept at 14.8 +/- 3 mmHg (1.97 +/- 0.40 kPa), and left ventricular stroke work index fell, whilst cardiac output increased. Sodium nitroprusside seemed to be useful in coronary arterial surgery if used with care.     

Surgical Repair of Infected Peripheral Graft and Abdominal Aortic Aneurysm Using Arterial Homograft

We report a case of combined surgical repair including lower limb revascularization (below-knee bypass) and abdominal aortic aneurysm repair using cryopreserved arterial homograft. The patient experienced lower limb ischemia due to repeated thrombosis of a long-infected polytetrafluoroethylene (PTFE) graft, and was also shown to have a complicating abdominal aortic aneurysm. Infection was eradicated with total graft excision and intravenous antibiotics. Two-year patency of the in situ arterial homograft revascularization was demonstrated with hemodynamic and tomographic controls; no degenerations have been found to date. Benefits of the use of in situ arterial homograft for arterial reconstruction may include improved hemodynamics and greater resistance to infection compared to when alloplastic materials are used. Because of the risk of allograft deterioration, close follow-up of the patient is required.     

Vascularity of the carpus

Relatively few studies investigating the vascular patterns of the carpus have been performed. Technical difficulties in identifying small vessels in three dimensions and in determining their location within the thick ligaments about the wrist have led to conflicting anatomic reports. Studies on cadavers in which improved techniques with arterial injection, chemical debridement, and decalcification were used allowed the arterial anatomy of the carpus to be delineated more accurately. The current authors review these arterial patterns, with attention given to the extraosseous and intraosseous vascularities.     

Increased intraperitoneal pressure up to 15 mm Hg does not reliably induce haemodynamic changes in pigs

Haemodynamic alterations occur consistently with laparoscopic surgery in humans. These haemodynamic changes have never been reproduced in an animal model without additional potentiating factors. As these alterations may be deleterious in some patients and as the cause is only partly understood, we have used an animal model to study these changes. Pneumoperitoneum with intraperitoneal pressures of up to 15 mm Hg were produced in pigs, in the same way as for laparoscopic surgery in humans. Arterial pressure, cardiac output, pulmonary arterial pressure and systemic arterial resistance were assessed at baseline and after pneumoperitoneum had been produced. Intraperitoneal pressures of up to 15 mm Hg were not associated with consistent circulatory changes and we conclude that haemodynamic changes associated with laparoscopic surgery are dependent on species.      

The lesser saphenous vein: an underappreciated source of autogenous vein.

Use of the ipsilateral greater saphenous vein for arterial bypass procedures is frequently limited by previous stripping, bypass operations, or anatomic unsuitability. In such cases the contralateral greater saphenous vein or arm veins are often used. However, over the past 5 years we have used the lesser saphenous vein as a preferred alternative autogenous vein. Duplex scanning has been used in 311 cases for preoperative mapping and assessment with excellent correlation with actual anatomy found at operation. Harvest of the lesser saphenous vein has been facilitated by the use of a medial subfascial approach not requiring special positioning of the leg. A total of 91 lesser saphenous veins have been used for arterial bypass procedures; 66 of these were repeat cases. Vein use was 90.2%. In 40 of these cases the lesser saphenous vein was used as the entire conduit, including 10 in situ, 20 reversed vein (including 18 for coronary artery bypass), and 10 orthograde vein bypasses. In the remaining 33 cases the lesser saphenous vein was spliced to another vein to complete a bypass procedure. In the entire group, patency was 77% at 2 years. These data suggest that the lesser saphenous vein should be a principal alternative to ipsilateral greater saphenous vein for arterial bypass because of its ready availability, high use rate, ease of harvesting and preparation, and ideal handling characteristics.     

Temporary and permanent occlusion of cerebral arteries: indications and techniques

Permanent occlusion of the carotid and vertebral arteries has long been used as a treatment for certain aneurysms, tumors, arteriovenous fistulae, and traumatic injuries. Temporary occlusion of these vessels often is used to predict patient tolerance before permanent vessel occlusion. When inadvertent arterial occlusion or injury is considered to be a significant risk of an open or endovascular surgical procedure, temporary arterial occlusion may be used to assess tolerance for permanent occlusion. The results of temporary arterial occlusion testing are often used to determine the need and type of bypass graft to augment cerebral blood flow. Temporary arterial occlusion also may be used to arrest proximal blood flow during open or endovascular surgery.     

Femoral vessel entrapment and compartment syndromes following snakebite

A 15-year-old patient who had been bitten on the ankle by a snake presented with swelling extending to the chest wall, with significant haemostatic abnormalities. Compartment and femoral vessel entrapment syndromes are presented. Compartment syndrome is easily mimicked by snakebite without a compartment syndrome. Current measurement of intracompartmental pressure, diastolic or mean arterial blood pressure and resulting equations used to determine the need for fasciotomy do not take into account regional venous or arterial pressures. Combined vessel entrapment and compartment syndromes due to snakebite warrant urgent surgery once hypovolaemia and coagulopathy have been controlled.     

Cirugía vascular e hipertensión arterial

Arterial hypertension is a highly prevalent disease in vascular patients. As well as vasculopathy, it is related to elderly.Owing to high morbi-mortality in intra and postoperative period, endovascular procedures have been widely performed. Though short- term adverse events are lower, they are proceeded in high-risk patients. For that reason, the probabilitity of adverse events is as high as 5%.Postoperative-risk scales in peripheral vascular disease does not include arterial hypertension, but posterior studies have confirmed that arterial hypertension improves the reliability of such scales in order to predict complications.On the contrary, it is known that arterial hypertension treatment diminishes the incidence of perioperative adverse events.Beta blockers, nitrates, α blockers, calcium channel blockers and angiotensin-converting-enzyme inhibitors are currently used in the arterial hypertension treatment in patients suffering from vascular disease.     

Delivery of endovascular grafts by direct sheath placement into the aorta or iliac arteries

Delivery of endovascular grafts via femoral access in patients with iliac arterial tortuosity or occlusive disease can be problematic. Aortomonoiliac grafts or arterial conduits sewn to proximal iliac arteries through an abdominal incision have been used as alternatives. A technique is described in which the proximal access vessel, aorta or iliac artery, is punctured directly and a large sheath inserted, through which the endovascular graft may be delivered. Hemostasis is achieved by use of a superficially placed concentric double purse-string suture. The technique has been employed successfully for placement of both thoracic and abdominal endografts.     

Improved cannulation method for extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation has been shown to be useful for patients in reversible cardiogenic shock. Effective arterial cannulation techniques for infants have been developed that are simple to use and require minimal subsequent vascular repair or reconstruction after removal. Groin cannulation in adults frequently requires bidirectional arterial cannulation to ensure adequate distal perfusion as well as frequent complex arterial repairs after discontinuation. We describe a simple arterial cannulation technique using a single right-angle, high-flow arterial cannula. With this technique adequate bidirectional arterial perfusion is maintained with a single arterial cannula while the need for vascular repairs or reconstruction is minimized.     

In situ femoral to popliteal bypass graft using superficial femoral vein to popliteal vein

During the evolution of vascular surgery as a specialty, many conduits have been used to revascularize the lower extremities. Superficial veins and prosthetic materials make up the majority of materials used to bypass diseased segments of native artery. The deep veins of the thigh have also been reported as alternatives for arterial bypass. However, the use of the in situ superficial femoral and popliteal vein bypass has not been reported to our knowledge in current literature. We report a 79-year-old white female with lower extremity rest pain who underwent an in situ femoral popliteal bypass graft for limb salvage.     

Arterial waveform analysis for the anesthesiologist: past, present, and future concepts

Qualitative arterial waveform analysis has been in existence for millennia; quantitative arterial waveform analysis techniques, which can be traced back to Euler's work in the 18th century, have not been widely used by anesthesiologists and other clinicians. This is likely attributable, in part, to the widespread use of the sphygmomanometer, which allows the practitioner to assess arterial blood pressure without having to develop a sense for the higher-order characteristics of the arterial waveform. The 20-year delay in the development of devices that measure these traits is a testament to the primitiveness of our appreciation for this information. The shape of the peripheral arterial pressure waveform may indeed contain information useful to the anesthesiologist and intensivist. The maximal slope of the peripheral arterial pressure tracing seems to be related to left ventricular contractility, although the relationship may be confounded by other hemodynamic variables. The area under the peripheral arterial pressure tracing is related to stroke volume when loading conditions are stable; this finding has been used in the development of several continuous cardiac output monitors. Pulse wave velocity may be related to vascular impedance and could potentially improve the accuracy of waveform-based stroke volume estimates. Estimates of central arterial pressures (e.g., aortic) can be produced from peripheral (e.g., brachial, radial) tracings using a Generalized Transfer Function, and are incorporated into the algorithms of several continuous cardiac output monitors.     

Duplex scanning for assessment of mesenteric ischemia

The accurate diagnosis of mesenteric arterial occlusive disease has in the past required invasive examination, primarily arteriography. Recent innovations in duplex ultrasound scan technology have for the first time provided a method for the noninvasive assessment of the splanchnic circulation in man. Mesenteric duplex scanning has been used successfully to measure postprandial changes in celiac and superior mesenteric arterial blood flow as well as changes in visceral flow produced by other pharmacologic stimuli.     

Combined cuff and suture technique for orthotopic whole intestinal transplantation in rats

For the purpose of immunological study on small intestinal transplantation (SIT), rat SIT models using direct suture technique widely have been used, which requires at least several months of training for microsurgery. Alternatively, a simple cuff technique for SIT has been mainly used by us, which reduces warm-ischemic time and the training period, but the entire intestinal grafts usually obtain a limited blood supply. This report describes a modification of a combined cuff and suture technique for rat SIT to aid beginning microsurgical transplantation researchers. The advantages are 1) use of only arterial suturing, making it easier for beginners, with the cuff technique applied to the more difficult vein anastomosis; 2) achievement of better arterial inflow and graft survival than when the arterial cuff technique is used; and 3) doing only partial clamping of the aorta, which improves animal survival and success of the procedure. A very high successful rate in orthotopic whole SIT was achieved even by beginners.     

Selection of amputation level. Comparison between morphine puncture test and skin perfusion pressure

In 46 amputations performed on account of peripheral occlusive arterial disease, the morphine puncture test (MPT) and the local skin perfusion pressure measurement (SPP) were carried out preoperatively. Below-knee (BK) amputation was performed when the SPP was greater than or equal to 40 mm Hg unless clinical criteria indicated otherwise. Out of 12 BK amputations without any clinical skin changes, where the SPP was greater than or equal to 40 mm Hg but the MPT was negative, healing was achieved in 11 patients. Thus, if the MPT had been used as an objective method to determine the amputation level, 11 knees would have been sacrificed. The MPT is thus not suitable for determination of amputation level in patients with peripheral occlusive arterial disease.     

Angioscopy as an adjunct to arterial reconstructive surgery: a preliminary report

To date our use of angioscopy as an adjunct to in situ vein grafting, arterial embolectomy, femoropopliteal bypass surgery, and laser recanalization has been studied in 11 patients. Three angioscopes have been used: a 1.7 mm optiscope, a 2.8 mm laser optiscope, and a 3.2 mm bronchoscope. Scopes were introduced through an arteriotomy and a clear field maintained by continuous saline infusion. Twenty-four angioscopic evaluations were performed in the 14 patients studied. Adequate visualization was achieved with all three scopes. Angioscopy showed total atherosclerotic occlusion of six superficial femoral and popliteal arteries, intimal flaps in two arteries, thrombus in two arteries and one graft, adequate valvulotomy in three saphenous veins used for in situ bypass grafting, and removal of thrombus after embolectomy in one artery. With the 2.8 mm laser optiscope, the optical fiber used for laser recanalization could be positioned at the site of arterial occlusion before lasing and recanalization were done under direct vision. The 1.7 mm scope could be passed through the recanalized artery to inspect the channel and confirm communication with the artery distal to the occlusion. Thus, angioscopy appears to be potentially useful as a diagnostic device in arterial occlusive disease and as an adjunct in in situ saphenous vein grafting or laser recanalization of occluded arterial segments.