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Biomedical subjects

R Berguer

Publications and source records attributed to R Berguer.

At least 91 records · Page 5Linked to original sources
PubMed1976

Vertebral artery bypass.

The origin of the vertebral artery is a frequent site for the development of stenosing lesions. The flow deficit caused by the stenosis of one vertebral artery is normally compensated for by intracranial anastomosis between the carotid and basilar arteries or by the opposite vertebral artery. A number of patients, however, have inadequate intracranial anastomosis and hypoplasia or stenosis of the opposite vertebral artery, and symptoms of brain ischemia develop. We describe here four cases in which a new technique, a subclavian vertebral artery autogenous vein bypass graft, was used to deal with the diseased segment of the vertebral artery. Transient postoperative problems included lymphocele and Horner syndrome. All four bypasses were patent at the time of angiography one week postoperatively. All four patients were relieved of symptoms of vertebrobasilar insufficiency.

Aged↗
PubMed1975

Geometry, blood flow, and reconstruction of the deep femoral artery.

The deep femoral artery is the main source of blood supply to the leg and foot when the superficial femoral artery is occluded. In this situation, the geometry of the trunk of the deep femoral artery represents a stenosis of 50 per cent interposed between the common femoral artery and the collateral circuit of the deep femoral artery. Intimal thickening of only 0.5 and 1.0 mm increases this anatomic stenosis to 64 and 76 per cent, respectively. Beyond the trunk, the cross-sectional area of the deep femoral artery circuit increases at each arterial division. Any reconstruction of the deep femoral artery intended to increase its inflow must extend down to at least its first important bifurcation if it is to overcome this trunk "stenosis". This requirement ex plains the effectiveness of proper reconstruction of the deep femoral artery in avoiding or delaying amputation in patients with ischemic symptoms and occlusion of the superficial femoral artery who are not candidates for femoropopliteal reconstruction. In this group, the absence of plaque on the arteriogram does not contraindicate reconstruction.

Angiography↗
PubMed1974

Critical arterial stenosis: a theoretical and experimental solution.

The mechanics of critical stenosis of a blood vessel are studied by means of a comprehensive theoretical model in terms of energy changes and dissipation. These theoretical assumptions correlate well with experimental data obtained in vivo. Previous work in this field is analyzed. This new treatment of the phenomenon of blood vessel stenosis allows explanation of apparent contradictions in previous studies. When the velocity of flow in the unstenosed portion and the geometry of the stenosis are known, the drop in pressure at flow can be predicted.

Animals↗
PubMed1973

Extended deep femoral angioplasty.

At present reconstructive arterial surgery for atherosclerotic disease below the level of the inguinal ligament is restricted to femoropopliteal bypass grafts. We have found a new operation, which we call extended deep femoral angioplasty, to be effective not only in some cases where bypass is possible but also in many cases where it is impossible because of a poor run-off, lack of a suitable vein, or even when a bypass has failed. In a consecutively treated group of 34 patients operative reconstruction was limited to the deep femoral artery and a success rate of 65% was achieved. Most gratifying was the saving of a leg in eight patients in whom bypass was impossible.

Amputation, Surgical↗
PubMedDate not supplied

Laparoscopy-guided intracorporeal ultrasound accurately delineates hepatobiliary anatomy.

UNLABELLED: The purpose of this study was to develop a technique and assess the ability of a laparoscopic ultrasound probe to delineate biliary antomy and to determine the presence or absence of duct stones. METHODS: Five pigs had ultrasonography of biliary structures and liver at laparoscopy followed by cholangiograms and anatomical dissection. Five patients had ultrasonography of the biliary tract at laparoscopic cholecystectomy. RESULTS: All animals had adequate visualization of important hepatobiliary structure, and an optimal method of accessing these structures at laparoscopy was established. Patients had ultrasonography which used methods developed in the animal trial. All had adequate visualization of the entire common bile duct confirmed by cholangiography. Limitations in demonstrating the relationship of the cystic duct to the common duct were technical and can be corrected. CONCLUSION: Laparoscopic ultrasonography has significant potential for delineation of biliary anatomy and determination of presence or absence of duct calculi. Clinical implementation could minimize the risk of iatrogenic duct injury and the need for operative cholangiography.

Animals↗
PubMedDate not supplied

Laparoscopic surgery in the rat. Description of a new technique.

We report a method of laparoscopic surgery in the rat. Our technique is illustrated by gastric fundoplication requiring two-handed dissection, suturing, and knot tying. This model for laparoscopic surgery is relatively inexpensive, can be extended to other operations, and makes use of an extensively studied animal. These factors may facilitate investigation of the physiologic effects of minimal access surgery.

Animals↗
PubMedDate not supplied

Neuroendocrine stress response after minimally invasive surgery in pigs.

Minimally invasive operations such as laparoscopic cholecystectomy appear to result in more rapid recovery of normal function, less physiological disturbance, and presumably less stress to the organism than open operation counterparts. The purpose of this study was to determine the stress response associated with minimally invasive surgery compared to conventional laparotomy. Three groups of pigs underwent general endotracheal anesthesia. The first group had laparoscopic cholecystectomy, the second open cholecystectomy, and the last group (controls) had only general anesthesia. The neuroendocrine serum stress markers adrenocorticotropic hormone (ACTH), cortisol, insulin, and glucagon were measured prior to anesthesia and for the first 3 postoperative days. Analysis of the data showed significant elevations of both ACTH and cortisol for laparoscopic operations as well as for open operation (cortisol only) in the immediate postoperative period. No differences were found for the other serum stress markers. We conclude that minimally invasive surgery in this porcine model confers no advantage, as measured by four neuroendocrine stress hormones, over conventional surgery. Further study is required to determine the clinical implication of these findings.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

One stage carotid artery resection: reconstruction in radiated head and neck carcinoma.

PURPOSE: Management of the carotid artery involved with metastatic squamous cell carcinoma continues to be a topic of much discussion. Early reports, for the most part, focused on the sequel of ligation and the development of various tests to predict patient tolerance for the procedure. More recent alternatives have described resection reconstruction in multistage procedures. By using immediate reconstruction with autogenous arterial grafting, carotid artery resection can be accomplished in patients with radiation failure in a single stage. This technique can be used without the addition of myocutaneous flaps, controlled fistulas, or intracranial surgery advocated for usage with alternative techniques. PATIENTS AND METHODS: Immediate reconstruction after resection of the carotid artery with superficial femoral arterial graft is described. RESULTS: In a series of 18 high-risk patients with radiation failure, the artery was successfully resected and reconstructed in 1 stage without any neurologic or vascular complications. The technique has been associated with prolonged survival in selected patients. CONCLUSION: Carotid artery resection and immediate reconstruction can be performed in high-risk radiation failure patients with acceptable complications, and is associated with prolonged survival in selected cases.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Measurement of intracellular gamma-interferon, interleukin-4, and interleukin-10 levels in patients following laparoscopic cholecystectomy.

Major surgery suppresses intracellular T-cell cytokine production. Laparoscopic surgery has been reported to have no effect on in vitro lymphocyte reactivity, but its effects on intracellular cytokine production are unknown. This study measured T-cell intracellular gamma-interferon, interleukin-4 (IL-4), and interleukin-10 (IL-10), along with serum interleukin-6 (IL-6) and cortisol levels, immediately before and 1 day after laparoscopic cholecystectomy in a cohort of six Air Force and veteran patients. Stimulated intracellular levels of gamma-interferon were slightly, but not significantly, elevated during the postoperative period in all T-cell subsets. There were no postoperative changes in stimulated IL-4 or IL-10 levels. Postoperative serum IL-6 levels, but not serum cortisol levels, were significantly elevated compared to preoperative values. In conclusion, laparoscopic surgery causes slight trauma but has no effect on T-cell intracellular interferon, IL-4, and IL-10 responses.

Adult↗
PubMedDate not supplied

Carotid artery noninvasive testing is being overused.

The most frequent tests done in the evaluation of patients with potential cerebrovascular disease are Oculoplethysmography (OPG) and Imaging procedures. These procedures are useful in the evaluation of asymptomatic carotid bruits and may be helpful in evaluating patients with nonhemispheric symptoms. However, there is no reasonable indication for the use of these noninvasive procedures on patients with lateralizing hemispheric or ocular transient ischemic attacks. Lateralizing transient ischemic attacks are very often caused by ulcerated non-stenosing lesions which are easily missed by these noninvasive means. Arteriography is mandatory in this group whenever the patient is a potential surgical candidate should an appropriate lesion be found. Finally, progress made in bruit analysis is acknowledged but the clinical relevance of this datum is questioned.

Angiography↗
PubMedDate not supplied

The application of ergonomics in the work environment of general surgeons.

Ergonomics, also called human factors engineering, is the study of the behavior and activities of individuals in relation to the working environment and the mechanical and electronic equipment operated by the worker. The function of specialists in ergonomics is to design or to improve the workplace, equipment, and procedures of workers to ensure the safe, healthy, and efficient achievement of personal and organizational goals. Many mental and physical similarities can be found between the work of a surgeon and the jobs of skilled industrial and military personnel. This review addresses the necessity for applying ergonomics in surgical working activities. The materials reviewed here are classified into the following topics in surgical ergonomics: Visualization, manipulation, posture, mental and physical workload, and the operating-room environment. It was concluded that the discipline of ergonomics can enhance our understanding of the way in which surgeons work. As surgeons confront increasingly complex and costly procedures, the need to cut health-care costs deems it necessary to develop a scientific understanding of the mechanics of surgical operations.

Equipment and Supplies↗
PubMedDate not supplied

Simultaneous carotid-vertebral reconstruction.

Vertebral atherosclerotic lesions frequently coexist with lesions in the carotid arteries. The most common cause of vertebrobasilar symptoms is hypoperfusion which may be relieved by correction of a critical carotid stenosis. A safe record with direct vertebral revascularization has led us to do simultaneous correction of lesions in the carotid and vertebral arteries through a single cervical incision. To evaluate combined carotid and vertebral reconstruction, procedures performed in a five-year period (1982 to 1987) were retrospectively studied. Thirty-six patients had combined carotid-vertebral reconstruction. In 10 patients, the primary indication was critical carotid disease; 26 patients had vertebrobasilar symptoms. The procedures performed were carotid endarterectomy with either vertebral reimplantation (22) or distal vertebral bypass (7), or external carotid angioplasty with either vertebral reimplantation (3) or distal vertebral bypass (4). Combined carotid-vertebral procedures are effective in relieving symptoms of hypoperfusion in the vertebrobasilar system. A specific lesson learned is that a distal vertebral bypass must not be done in conjunction with an external carotid angioplasty.

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