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Biomedical subjects

L H Hollier

Publications and source records attributed to L H Hollier.

At least 19 recordsLinked to original sources
PubMed1992

The value of flow cytometric analysis in multicentric glomus tumors of the head and neck.

Glomus tumors of the head and neck include those arising from the carotid body, jugular vein, and vagus nerve. Because these cannot be differentiated histologically, when encountering a large tumor mass involving more than one structure in the carotid sheath, one often cannot be sure whether the tumors are from one or more of these structures. The authors performed DNA flow cytometric analysis on a patient with a multicentric glomus tumor on the right side of the neck involving the carotid body, jugular vein, and vagus nerve, in an effort to determine the separate or similar origin of her tumor mass. Different DNA indices, including a double peak for the carotid body tumor, were obtained. There were three aneuploid tumors and one diploid tumor (DNA indices: carotid body 1.78, 2.04; jugular vein 2.20; vagus nerve 1.82). Different synthetic phase fractions were calculated for each aneuploid tumor except the second carotid body peak (carotid body 7.2; jugular vein 3.6; vagus nerve 4.8). The authors conclude that DNA flow cytometry may be useful in confirming the multicentric origin of tumors that encompass more than one histologically similar structure.

Adult↗
PubMed1992

Risk of spinal cord dysfunction in patients undergoing thoracoabdominal aortic replacement.

The records of 150 consecutive patients undergoing thoracoabdominal aortic replacement from 1980 to 1991 were retrospectively reviewed. There were 89 men and 61 women; mean age was 67.8 years (range: 33 to 88 years). Since June 1989, a multimodality prospective perioperative protocol was used to reduce the risk of spinal cord dysfunction. Ischemia is minimized by complete intercostal reimplantation whenever possible, cerebrospinal fluid drainage, and maintenance of proximal hypertension during cross-clamping. Spinal cord metabolism is reduced by moderate hypothermia, high-dose barbiturates, and avoidance of hyperglycemia. Reperfusion injury is minimized by the use of mannitol, steroids, and calcium channel blockers. Ninety-seven percent of patients survived long enough for evaluation of their neurologic function. Spinal cord dysfunction was reduced from 6 of 108 (6%) in the preprotocol group to 0 of 42 in the protocol group (0%) (p less than 0.01). The overall 30-day operative mortality was not significantly different between the groups (9% versus 12%, p = NS). A multimodality protocol appears to be effective in reducing the risk of spinal cord injury during thoracoabdominal aortic replacement.

Adult↗
PubMed1992

Selection of patients for peripheral revascularization surgery.

The recognition of the extent of vascular disease has introduced several medical subspecialties, radiology and vascular surgery, to a multidisciplinary approach to these problems. Of particular importance is the primary care physician, who often is the first to see these patients and should be familiar with common vascular problems. Only then will initial care and disposition be appropriate.

Humans↗
PubMed1992

Protecting the ischemic spinal cord during aortic clamping. The influence of anesthetics and hypothermia.

Infrarenal circumaortic occlusion devices were operatively placed in 74 New Zealand white rabbits. Two days after operation the animals were randomly assigned to one of seven treatment groups: I, control, n = 23; II, halothane, n = 8; III, thiopental, n = 12; IV, ketamine (30 mg/kg intravenously), n = 6; V, halothane+hypothermia, n = 8; VI, thiopental+hypothermia, n = 12; VII, ketamine+hypothermia, n = 5. In each group, the infrarenal aorta was occluded for 21 minutes. Final neurologic recovery after restitution of blood flow was graded as acute paraplegia, delayed paraplegia (neurologic deficit developing after initial recovery), or normal. Halothane alone was of no benefit. Hypothermia with any anesthetic was completely protective and reduced neurologic deficits to 0% compared with 91% in controls (p less than 0.05). Thiopental and ketamine treatment each reduced acute paraplegia to 17% (as compared with 61% in controls) and increased delayed paraplegia from 30% in controls to 75% and 50%, respectively (p less than 0.05 for thiopental, p = 0.10 for ketamine). The authors interpret the increase in delayed deficits and decrease in acute deficits as being the result of partial spinal cord protection. These findings document that this model of spinal cord ischemia is sufficiently sensitive to identify interventional treatments that protect the ischemic spinal cord.

Anesthetics↗
PubMed1992

Optimizing the management of orbitozygomatic fractures.

Our understanding of the biomechanics and current management of orbitozygomatic fractures has evolved with the development of craniomaxillofacial surgery. Early management was minimal, with reduction alone as the uniform treatment, and the only variation was the approach used. However, a critical review of the literature using these methods revealed that many of these fractures were unstable after simple reduction alone. Using the principles of craniofacial surgery, our clinical experience, and the data presented in this article, a pragmatic algorithm for optimizing the management of orbitozygomatic fractures is presented. Our approach to this problem has been graduated, with orbitozygomatic fractures being divided into two general categories: nondisplaced and displaced. The nondisplaced orbitozygomatic fracture is treated nonoperatively, with close patient follow-up to detect signs of malunion. Displaced fractures are openly reduced and rigidly fixed internally with mini- and/or microplates. The orbit is routinely explored, especially in high-velocity injuries. The orbit is anatomically as well as volumetrically reconstructed with bone grafts, if needed, to prevent postoperative enophthalmos.

Adult↗
PubMed1992

Management of frontal sinus fractures. Changing concepts.

Since the turn of the century, surgeons have handled frontal sinus fractures with a variety of different procedures. The optimal management procedure remains controversial. We have presented a graduated anatomic algorithm for treatment of frontal sinus fractures based on the degree of fracture displacement and nasofrontal duct involvement and presence of CSF leak. Nondisplaced fractures are best handled conservatively, without operative intervention. However, the majority of frontal sinus fractures require operative correction. Uncomplicated anterior table displacement with an aesthetic deformity is treated by fragment reduction and stabilization with miniplates or microplates or wires. Nasofrontal duct obstruction is usually managed by sinus obliteration with spontaneous osteoneogenesis or autologous bone grafting. Finally, comminuted, displaced anterior and posterior table fractures, especially those with persistent CSF leakage and associated nasofrontal duct involvement, are best handled with frontal sinus cranialization. The presented algorithm is simply a treatment guideline. Frontal sinus fracture management must be individualized. However, this graduated anatomic approach provides a pragmatic framework for decision making and understanding this complex and controversial topic.

Bone Transplantation↗
PubMed1992

Aneurysmal disease.

The frequency of the diagnosis of arterial aneurysms is increasing. Aneurysms in many locations remain asymptomatic and require careful evaluation of at-risk patient populations. Screening of first-degree relatives of patients with known AAA now appears to be indicated. A high index of suspicion of the possible presence or the existence of known aneurysms should prompt timely referral for evaluation by a vascular surgeon. Consideration of a patient's candidacy for surgical intervention should involve the evaluation of a myriad of factors, some of which have been elucidated in this overview. The safety of surgical intervention for aneurysm repair has continued to improve, and most patients can be surgically managed with an acceptably low rate of morbidity and mortality.

Aneurysm↗
PubMed1991

Guiding catheter-assisted renal artery angioplasty.

A guiding catheter was used in seven patients who underwent balloon dilation of nine renal arteries. The advantages of using a guiding catheter for renal angioplasty are analogous to the benefits obtained with a coronary angioplasty guiding catheter used in coronary angioplasty. The guiding catheter provides back-up support to cross lesions and allows selective contrast visualization of the lesion before, during, and after dilation. It is also possible, when using a guiding catheter, to measure pressure gradients across lesions without having to recross the lesion which may help to ensure that adequate dilation of the stenosis has been accomplished.

Aged↗
PubMed1991

Prognostic value of DNA flow cytometry in paragangliomas of the carotid body.

A carotid body tumor is a paraganglioma of the carotid bifurcation. Histologic appearance does not correlate with the malignant potential of the lesion, and thus a reliable prognostic marker for these tumors is lacking. To determine whether flow cytometric analysis of paraffin block specimens by DNA index and synthetic phase fraction (SPF) would be of prognostic value, a retrospective chart review of 14 patients with carotid body tumors was performed. Three of 14 tumors were aneuploid and were the only tumors with SPF greater than 15%. One of 3 patients (33%) with an aneuploid tumor (SPF = 22%) developed a local recurrence; no patient with a diploid tumor developed a recurrence. Two of 3 (67%) patients with aneuploid tumors (SPF = 18%) but only 1 of 11 (9%) with a diploid tumor were symptomatic preoperatively (P = 0.03). DNA index and SPF may help select a subgroup of patients with more aggressive tumors who are at increased risk for recurrence and therefore require closer follow-up.

Adult↗
PubMed1991

Celiac artery aneurysm.

Aneurysms of the celiac artery are unusual lesions and account for only 4% of all splanchnic aneurysms. In recent years, the incidence has been noted to rise because of the increased use of sonography, computerized tomography, and arteriography. Although patients are often asymptomatic at the time of diagnosis, the risk of rupture is high; therefore, surgical resection should be undertaken in acceptable candidates. We report the case of a large celiac artery aneurysm treated with distal pancreatectomy and celiac artery aneurysmectomy.

Aneurysm↗
PubMed1991

"Shaggy" aorta syndrome with atheromatous embolization to visceral vessels.

Spontaneous atheromatous visceral embolization from diffuse aortic atherosclerotic disease is an unusual and poorly understood entity. We have reviewed our experience with 88 patients who suffered atheromatous embolization from a "shaggy" aorta. Visceral embolization was evident in 36 patients (40.9%). Nine were treated nonoperatively with three patients dying within a week of presentation and an additional five patients dying within five years due to continuing renal and intestinal embolization. Surgical correction was undertaken 28 times in 27 patients. Endarterectomy or graft replacement of the aorta did not necessarily prevent visceral infarction or renal failure. Extra-anatomic bypass with ligation of the distal external iliac arteries appears to be associated with the lowest morbidity and mortality. Anticoagulation of these patients does not prevent embolization and may be contraindicated for long-term management.

Aged↗
PubMed1991

Ultrasound-guided balloon angioplasty is a new technique for vascular surgeons.

A new catheter has been developed that can be accurately and precisely positioned using duplex ultrasonography alone. A piezoelectric transducer that functions as a passive, omnidirectional receiver is attached to the mid-balloon region of an angioplasty catheter. Integration to a standard duplex imaging system allows visualization of this receiver in all planes, with the location of the receiver represented by a flashing bright arrow superimposed on the ultrasound B-mode image. This catheter was tested successfully in 10 dogs with bilateral femoral arteriovenous fistulas. With the use of duplex guidance, eight arterial and three venous stenoses were dilated and two stents were placed. Catheter placements and therapeutic outcomes predicted by ultrasound correlated with arteriographic findings. Ultrasound guidance has several advantages. It eliminates the risks associated with radiographic imaging. It also reduces patient costs and discomfort. Furthermore, procedures can be monitored continuously in real time with the collection of anatomic and physiologic data.

Angiography↗
PubMed1991

The influence of severity of spinal cord ischemia in the etiology of delayed-onset paraplegia.

To clarify the cause of delayed-onset paraplegia, the authors evaluated the neurologic outcome after temporary (10 to 30 minutes) spinal cord ischemia in the awake rabbit. Loss of motor function occurred in less than 2 minutes in all animals. Restoration of flow within 16 minutes always resulted in full return of function, whereas with occlusion times of greater than 27 minutes all animals remained paralyzed. After temporary occlusion of 20 to 21 minutes, however, 71% of animals returned to normal neurologic function but developed delayed-onset paraplegia 14 to 48 hours later. This appears to be a reliable method for the creation of a model of delayed-onset paraplegia in the awake animal, and will facilitate more detailed studies of the pathophysiology of ischemia-induced paraplegia.

Animals↗
PubMed1991

Superior vena cava and central venous reconstruction.

Partial or complete obstruction of the superior vena cava and its major tributaries occassionally results in incapacitating venous hypertension of the upper extremities and/or head and neck. Factors intrinsic and extrinsic to the central veins play a role in the pathogenesis. The more common causes include mechanically and chemically induced intimal injury with resultant fibrosis, sclerosis, or thrombosis and neoplastic masses with external compression or direct extension in the central venous structures. Medical therapy is indicated in the acute situation and generally allows the time necessary for development of collateral drainage routes. Persistent or progressive symptomatic venous hypertension develops in 5% to 40% of these patients, and approximately 10% of the patients will remain incapacitated. Presented here is a series of 10 patients who underwent reconstruction of the superior vena cava or central veins for incapacitating venous hypertension of the upper extremities and/or head and neck. Reconstruction was accomplished by venous transposition (three patients), externally reinforced ePTFE (six patients), and reversed saphenous vein graft (one patient). No perioperative deaths occurred; however, two late deaths occurred at 3 and 9 months after reconstruction from causes unrelated to the operative procedure. One patient experienced early postoperative graft thrombosis requiring thrombectomy, after which the graft remained patent. All patients had patent grafts and were asymptomatic with respect to their venous disease at the time of preparation of this manuscript, with a mean follow-up period of 30 months. Specific details concerning these 10 cases are discussed and integrated with a focused review of the literature and the historic development of the intraoperative techniques and postoperative care that facilitate the successful management of patients with symptomatic central venous occlusion.

Blood Vessel Prosthesis↗