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Biomedical subjects

N M Rich

Publications and source records attributed to N M Rich.

At least 73 records · Page 4Linked to original sources
PubMed1984

Vascular injury related to lumbar disk surgery.

This report summarizes the Walter Reed Army Medical Center experience with six patients operated on from 1949 through 1982 for vascular injury related to lumbar disk surgery. All had common iliac artery injuries generated by L4-5 disk operations. Four patients had isolated arterial injuries and two had combined arteriovenous injuries. Three underwent vascular repair acutely, two with shock and one with a false aneurysm. Delay in diagnosis occurred in two patients who presented 6 weeks and 3 years postinjury with minimally symptomatic arteriovenous fistulae. A sixth patient had a known arterial injury and was operated on after a 1-month delay. All patients survived. Two patients had had repeated back operations, suggesting that this may be a risk factor for perforation of the anterior spinal ligament by an operative rongeur.

Adult↗
PubMed1984

Asymptomatic cervical bruit and abnormal ocular pneumoplethysmography: a prospective study comparing two approaches to management.

Fifty-seven patients with cervical bruits and abnormal ocular pneumoplethysmography but without symptoms were followed prospectively. Mean follow-up was 32 months and all patients were followed for at least 1 year. Twenty-nine patients consented to join a randomized study comparing treatment with aspirin, close follow-up, and no intervention unless symptoms developed [( NI: ASA] n = 14) versus intervention with arteriography and prophylactic surgery [( I: A/S] n = 15). Among patients who refused randomization, 14 were treated with NI: ASA and 14 with I: A/S. Endpoints for analysis included all unfavorable outcomes related to both management plans and included stroke, death of stroke, major angiographic and perioperative complications, asymptomatic carotid occlusion, and recurrent carotid artery stenosis. In both the randomized and nonrandomized portions of the study unfavorable outcomes were more frequent in patients treated with I: A/S, and by combining the results of both studies a significant difference was observed (N: ASA - 3.6% versus I: A/S - 31%; X:2 = 4.78; p less than 0.05). Among patients treated with NI: ASA, a single minor stroke occurred without warning. In patients from all groups who underwent arteriography, advanced carotid stenosis was found in 78% (mean percent diameter stenosis = 72% +/- 2%; mean residual lumen = 1.3 +/- 0.1 mm). We conclude that, despite the probability of underlying severe carotid stenosis, most patients with cervical bruit and abnormal ocular pneumoplethysmography but without symptoms are appropriately managed without intervention unless symptoms develop.

Aged↗
PubMed1983

Endothelial cell labeling with indium-111-oxine as a marker of cell attachment to bioprosthetic surfaces.

Canine vascular endothelium labeled with indium-111-oxine was used as a marker of cell attachment to vascular prosthetic surfaces with complex textures. Primarily cultured and freshly harvested endothelial cells both took up the label rapidly. An average of 72% of a 32 micro Ci labeling dose was taken up by 1.5 X 10(6) cells in 10 min in serum-free medium. Over 95% of freshly labeled cells were viable by trypan blue tests and only 5% of the label was released after 1 h incubations at 37 degrees C. Labeled and unlabeled cells had similar rates of attachment to plastic dishes. Scanning electron microscopic studies showed that labeled cells retained their ability to spread on tissue culture dishes even at low (1%) serum levels. Labeled endothelial cells seeded onto Dacron or expanded polytetrafluoroethylene vascular prostheses by methods used in current surgical models could be identified by autoradiography of microscopic sections of the prostheses, and the efficiency of cell attachment to the prosthesis could be measured by gamma counting. Indium-111 labeling affords a simple and rapid way to measure initial cell attachment to, and distribution on, vascular prosthetic materials. The method could also allow measurement of early cell loss from a flow surface in vivo by using external gamma imaging.

Animals↗
PubMed1983

Vascular trauma secondary to diagnostic and therapeutic procedures: 1974 through 1982. A comparative review.

One-hundred nineteen patients with 125 iatrogenic vascular injuries requiring surgical intervention were treated at Walter Reed Army Medical Center from 1974 through 1982. This experience was compared with that from 1966 through 1973 [1]. A decrease in the proportion of cases resulting from cardiac catheterization was partially offset by an increase in injuries from invasive monitoring and injuries from percutaneous transluminal dilation procedures. A threefold increase in cases resulting from urologic surgery was related to the evolution of an aggressive approach toward retroperitoneal metastatic tumor. Over half of the arterial injuries are now iliofemoral in location because of the routine use of the femoral approach for angiographic and cardiac catheterization procedures. The need for complex reconstruction in addition to thrombectomy increased fourfold. Delayed surgical intervention was a factor in 9 of the 12 patients with permanent disability. There was no death attributable to vascular reconstruction.

Angiography↗
PubMed1983

Seeding of Dacron vascular prostheses with endothelium of aortic origin.

Seeding of autologous venous endothelium on Dacron vascular prostheses in dogs results in endothelial coverage of the prosthetic flow surface 4-6 weeks after implantation. Canine aortic endothelium, in contrast, usually fails to completely cover an unseeded prosthesis by pannus ingrowth even over much longer periods. To see if the success of endothelial seeding stems from a difference in the ability of venous and aortic endothelium to grow on prosthetic surfaces, we seeded freshly harvested autologous aortic endothelium on Dacron velour infrarenal aortic prostheses in dogs. Six weeks after surgery these prostheses showed the features reported to be typical of seeded prostheses. Scanning electron micrographs showed a luminal lining of flat polygonal cells without fibrin or adherent formed blood elements, and light microscopy showed an underlying layer containing aligned spindle-shaped cells with elongated nuclei and cell-lined subluminal channels. Control prostheses were covered with fibrin and platelet-rich thrombi everywhere except for limited pannus ingrowth at anastomotic sites. The results suggest that the success of autologous endothelial seeding cannot be ascribed to inherent differences in properties such as mitotic capacity or fibrinolysis between venous and aortic endothelium. The formation of complete endothelial linings by seeding must instead result from a more favorable condition for endothelial cell growth created by the cell harvesting or seeding process itself.

Animals↗
PubMed1983

Isolated venous injury produced by penetrating trauma to the lower extremity.

Simple ligation of major venous injury can be both limb threatening and create chronic disability (9). A case of penetrating trauma to the thigh producing isolated major venous injury is presented. An aggressive approach, immediate exploration, and lateral suture and non-reversed saphenous vein graft, are advocated for the diagnosis and treatment of venous trauma.

Accidents↗
PubMed1983

Dilation of knitted Dacron aortic prostheses and anastomotic false aneurysms: etiologic considerations.

Five patients with knitted Dacron aortic bifurcation prostheses developed prosthetic dilation and anastomotic false aneurysms. The interval between placement of prostheses and secondary presentation ranged from 4 to 10 years. Three patients presented with femoral false aneurysms (one ruptured) and two presented with aortic false aneurysms (one ruptured). In all cases, anastomotic sutures remained intact on the prosthesis and there was no evidence of infection. The mean (+/- SEM) increase in diameter of prostheses was 85.7 +/- 19.1% (range 76% to 137%). Dilated prostheses were removed in four cases and were tested for tensile strength and studied with scanning electron microscopy. These were compared to normal, nondilated knitted Dacron prosthetic fabric from the same manufacturer. There was no loss of breaking strength in dilated prostheses. Furthermore, on examination with scanning electron microscopy, there was no evidence of degeneration or fracturing of individual Dacron filaments. However, dilated prostheses were found to have a greatly expanded knit. The distance between loops was significantly increased and the number of fibers per 1000 microns was significantly less in comparison to normal knitted Dacron fabric. These studies confirm an association between prosthetic dilation and false aneurysm formation. Further, they suggest that the cause of prosthetic dilation is loss of compactness of the knit not associated with intrinsic Dacron fiber deterioration. A fabrication defect is most likely responsible.

Aged↗
PubMed1983

Percutaneous transluminal balloon angioplasty of the iliac artery for contralateral ischemia.

The cases of three patients with lower extremity ischemia from ipsilateral iliac artery occlusion and contralateral iliac artery stenosis are presented. Planned treatment was percutaneous transluminal angioplasty (PTA) of the contralateral iliac artery, rendering it an adequate donor vessel for subsequent femorofemoral bypass. Because of adequate collateral vessels across the pelvis, cross-femoral bypass was unnecessary following PTA. Current technology allows simultaneous intraoperative PTA and femorofemoral bypass. We do not recommend this on the basis of our experience.

Aged↗
PubMed1983

The Matas/Soubbotitch connection.

The Southern Association for Vascular Surgery, as one of the recently developed major regional vascular societies, has recognized the outstanding accomplishments of one of the vascular pioneers in the United States, Rudolph Matas, by including his profile in the Association logo. Although the contributions in vascular surgery by Matas are well known by all who have an interest in vascular surgery, the contributions of V. Soubbotitch have not been recognized widely in the English-speaking world. Matas proclaimed in an International Surgical Congress in London in 1913 that Soubbotitch had achieved clinical success that was unparalleled by repairing injured arteries and veins. Soubbotitch, Senior Surgeon, Belgrade State Hospital, Serbia (now part of Yugoslavia) and a Lieutenant Colonel in the Serbian Army Reserve during the Balkan Wars (Serbo-Turkish and Serbo-Bulgarian) initiated one of the first clinical programs that emphasized repair, rather than ligation, of injured arteries and veins. Surgeons from the capitals in Europe visited his clinic to assist in this effort, and the 1913 presentation in London included the experience of managing 77 injured large blood vessels, which resulted in 32 vascular repairs--19 arteriorrhaphies and 13 venorrhaphies. It is ironic that nearly 40 years passed before similar successful efforts were achieved during the latter part of the Korean Conflict (1952 to 1953). In this brief review we emphasize the connection between two outstanding surgical pioneers who shared mutual interest in the repair of injured vessels and in international surgical exchanges, Matas and Soubbotitch.

History, 19th Century↗
PubMed1983

Etiologic factors for recurrent carotid artery stenosis.

Since 1966, 29 patients with recurrent carotid artery stenosis have been encountered. The mean (+/- SEM) internal between initial carotid endarterectomy and secondary presentation was 67.5 +/- 9.2 months (range 6 to 180 months). There was a disproportionate number of women with recurrent stenosis. The mean age at initial endarterectomy in patients with recurrent stenosis, 54.6 +/- 1.4 years, was significantly less (P less than 0.001) than that of all patients who had endarterectomy. To define the etiologic factors for recurrence, 21 of these patients were matched with case-control patients of the same age and sex who had undergone endarterectomy the same year but did not develop recognized recurrent stenosis. There was no significant difference in the incidence of hypertension, diabetes mellitus, coronary artery disease, bilateral carotid disease, other vascular operations, or family history for atherosclerosis in patients with recurrent stenosis compared to control patients. The indications for primary endarterectomy, angiographic distribution of disease, and operative details were similar in both groups. There was no difference in the incidence of regular, therapeutic aspirin ingestion following initial endarterectomy (52.5% in both groups). There was a striking difference in smoking habits. Ninety-five percent of patients with recurrent stenosis continued to smoke following initial endarterectomy, compared to 23.8% of control patients (P less than 0.001). Lipid fractionation studies were performed in both groups, and there were no significant differences in levels of cholesterol, triglycerides, high-density lipoprotein (HDL)-cholesterol, and total cholesterol/HDL-cholesterol ratio. Dose-response platelet aggregometry detected no differences between groups in the sensitivity of platelets to adenosine diphosphate (ADP), collagen, and epinephrine. Reoperation in patients with recurrent stenosis was associated with minimal morbidity, no deaths, and generally excellent results.

Anesthesia↗
PubMed1982

Popliteal entrapment and adventitial cystic disease.

Both popliteal vascular entrapment and adventitial cystic disease of the popliteal artery have been recognized with increasing frequency during approximately the past 20 years. A knowledge of these lesions, which were previously thought to be rare and unusual, is mandatory in evaluating patients, particularly the younger, nonsmoking, nonarteriosclerotic, athletic man who has the sudden onset of intermittent claudication. With the increasing interest in these lesions and increasing consideration of these diagnostic possibilities, it will probably be recognized that these lesions are more common than has been thought.

Adult↗
PubMed1982

Hepatic blood flow after canine portasystemic shunting.

Effects of portasystemic shunting on total hepatic blood flow (THBF) were evaluated in mongrel dogs with 35 and 50micro radioactive microspheres. THBF was measured prior to shunting and 1 hour and 3 weeks after surgery. Using systemic and pulmonary artery catheters, pertinent hemodynamic variables were also measured. In sham-operated dogs (n = 5), there were no significant changes in the hemodynamic parameters or the components of THBF during the experiment. After end-to-side shunting (n = 7), animals experienced a significant, permanent fall in hepatopetal portal blood flow (HABF). In contrast, dogs with side-to-side shunts (n = 7) exhibited a transient, significant increase in HABF 1 hour after surgery. Although the shunt eliminated HPBF, the rise in HABF prevented a significant, immediate fall in THBF. Three weeks after surgery, however, HABF had returned to the baseline range, and THBF was significantly lower than the preshunt value. Dogs with H-graft mesocaval shunts (n = 5) also exhibited a transient, significant rise in HABF 1 hour after surgery. Since HPBF did not fall substantially, THBF at this time was significantly higher than the baseline value. Three weeks after surgery, HABF had fallen to the baseline range, but THBF was not significantly different from the preshunt level. In animals with distal splenorenal shunts (n = 11), there was no significant change in HABF after shunting. Both HPBF and THBF were transiently, significantly reduced immediately after surgery, but three weeks later neither parameter was significantly lower than the preshunt values. There were no significant, persistent changes in the systemic perfusion pressures or flows in the shunted groups. These experiments demonstrate that the reported increase in HABF following portasystemic shunting is dependent on the type of shunt and, if it occurs, is a transient phenomenon. Hence, immediate postoperative changes in hemodynamic variables or hepatic blood flows do not necessarily reflect long-term patterns. In the normal dog, total portasystemic shunting produces a permanent, significant decrease in THBF, whereas selective shunting maintains THBF in the near-normal range.

Animals↗
PubMed1982

Early normalization of platelet survival by endothelial seeding of Dacron arterial prostheses in dogs.

Current synthetic vascular prostheses do not acquire a complete lining of vascular endothelium in humans or dogs. Seeding of autogenous venous endothelium has bee reported to remedy this defect, but previous studies have been primarily morphologic. To see if venous endothelial seeding caused a measurable decrease in platelet-prosthetic interaction in vivo, serial 111In-labeled platelet survival studies were done in dogs with seeded (N = 8) and unseeded (n = 9) thoracoabdominal Dacron bypass prostheses.l Changes in platelet survival time (PST) were compared with endothelial coverage scores, which were determined by blinded survey of removed prostheses by scanning electron microscopy (SEM). The PSTs before surgery (+/- SD) were 5.02 +/- 0.79 days (seeded) and 5.31 +/- 0.99 days (control) (P = 0.51). Seven weeks after surgery the PSTs were 4.01 +/- 1.10 days (seeded) and 2.67 +/- 0.88 days (control) (P = 0.013). The subgroup of four dogs with seeded prostheses that had complete endothelial coverage showed restoration of the platelet survival pattern to that of the linear decay seen before surgery, SEM studies showed that this normalization of PST occurred despite the presence of small nidi of platelet adhesion on exposed Dacron fibers and irregularities of the endothelial pattern consistent with flow disturbances and venous jet lesions near anastomoses. Endothelial seeding, when technically successful, appears to sharply curtail the degree of platelet interaction with vascular prostheses and restores a normal platelet survival pattern. Longer studies of seeded prostheses are needed to determine if seeding protects against the late complications of intimal hyperplasia and thrombotic occlusion.

Animals↗
PubMed1982

Principles and indications for primary venous repair.

The management of injured veins continues to represent a formidable and stimulating challenge. While there has been past resistance to repair injured veins, and the controversy persists for some, an increasing number of reports emphasize that a more aggressive approach to the repair of injured veins is warranted, particularly in the lower extremities. The recent experience in Southeast Asia, as outlined in reports from the Vietnam Vascular Registry, has demonstrated that some of the previous fears of an increased incidence of thrombophlebitis or pulmonary embolism with attempted venous repairs are unfounded. The long-term follow-up of 10 years' duration or longer of 110 patients with isolated popliteal venous injuries documents significant edema in 51% of patients who had ligation of injured veins, in contrast to only 13% of those who had attempted venous repair. Recent civilian experience is similar to the military experience in Vietnam. Venous reconstruction remains one of the challenges in surgery in which additional development can be anticipated, in late reconstruction as well as the initial management of injured veins.

Follow-Up Studies↗
PubMed1982

Technical considerations in the study of indium-111-oxine labelled platelet survival patterns in dogs.

A detailed technique for labelling canine platelets with Indium-111-oxine for the study of platelet survival patterns in four to six dogs at a time was developed. Useful modifications of earlier methods included splitting of the platelet rich plasma into multiple aliquots to improve pelleting efficiency at low gravity forces, use of saved platelet poor plasma to flush out injection syringes, and prompt use of commercial Indium-111-oxine sources 3 to 5 minutes after mixing with Ringer's Citrate Dextrose. Avoidable pitfalls of the method included excessive lengths of incubation time in plasma free medium and loss of labelling efficacy by exposure of the chelate to iron or other metal contaminants in glassware. The method was used to study changes in platelet survival time in dogs with large synthetic arterial prostheses, and gave results in good agreement with earlier studies using Chromium-51 labelled platelets.

Animals↗
PubMed1982

Effects of portasystemic shunting on visceral and portal blood flow in the dog.

Late effects of portasystemic shunting on visceral and portal vein blood flows were evaluated in mongrel dogs with radioactive microspheres. Sham operation (n = 5) produced no significant long-term changes in visceral blood flow. In contrast, there was a significant increase in small bowel perfusion 3 wk after selective and nonselective portasystemic shunting: end-to-side (n = 7), side-to-side (n = 7), H-graft mesocaval (n = 5), and distal splenorenal (n = 11). Variable increases in pancreatic blood flow were noted in all shunt groups. Portal venous blood flow was significantly elevated in all dogs with total shunts and was substantially increased in animals with H-grafts. Compared with baseline levels, perfusion of organs left in continuity with the portal vein after splenorenal shunting was significantly increased. Blood flow from the small bowel was primarily responsible for the magnitude of the change in portal venous flow. The reduction in hepatic perfusion by portal venous blood appears to trigger these compensatory responses. A humoral mediator best explains the phenomena observed.

Animals↗
PubMed1982

Temporal arteritis.

Temporal arteritis is generally a benign and self-limiting disease, which has been recognized for approximately 50 years. Although it has been uncommon, it is becoming increasingly prevalent among elderly individuals. Its major complication involves loss of vision, and approximately 50 per cent of all untreated patients become blind in one or both eyes. This can be prevented by early recognition and prompt treatment of the disease process. Steroids given to suppress the inflammatory involvement of the arterial wall safeguard the blood supply to the eye. If vision is lost, however, the loss is usually permanent. Although its diagnosis can be confusing initially, temporal arteritis should be easily diagnosed by its local and systemic manifestations, including headache of recent onset in an elderly patient, visual disturbance, an increased sedimentation rate, and a classic palpable tenderness along the course of the temporal artery. Immediate hospitalization is recommended when the diagnosis is made and steroid therapy is begun, along with measures for symptomatic relief of headaches. With the increasingly aging population in the United States, one predicts that this disease entity of obscure etiology will become prevalent. Thus all physicians should have a basic knowledge and understanding of the disease process.

Aged↗