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At least 811 records · Page 45Linked to original sources

PubMed2001

The impact of new technology on hepatic resection for malignancy.

HYPOTHESIS: Relatively high morbidity rates remain problematic in hepatic resection for malignant neoplasms. Technological innovations coupled with surgical expertise can ameliorate morbidity and mortality rates. DESIGN: Medical records survey. SETTING: Tertiary care university hospital. PATIENTS: Five hundred one patients underwent liver resection at our hospital from March 1, 1988, through November 30, 1999. Three hundred twenty-one patients (64.1%) had primary carcinoma, whereas 180 (35.9%) had metastatic disease, mainly colorectal secondary disease (83.3%). Morbidity and mortality rates were compared with those of a previous series in the same setting. MAIN OUTCOME MEASURES: Special attention was paid to the impact of new technology (eg, newer imaging techniques, ultrasonic aspiration, intraoperative ultrasonography, argon beam coagulation, and autotransfusion) and improved anesthetic and surgical management on mortality and morbidity rates. RESULTS: Five patients died after liver resection and 93 patients had various complications, representing mortality and morbidity rates of 1.0% and 18.6%, respectively. These results compare favorably with the results of a previous unpublished series (mortality, 5/55 [9.1%]; morbidity, 28/55 [50.9%]). Intraoperative ultrasonography resulted in a change in operative strategy in 7 (17.5%) of a recent group of 40 patients. CONCLUSIONS: Morbidity after major hepatic resection for malignancy can be reduced considerably by applying newer technologies to preoperative and intraoperative decision making. Advanced technology also assists in reducing intraoperative risk by minimizing bleeding during resection of the hepatic parenchyma.

Aged↗

PubMed1988

YAG laser treatment of early carcinoma of the prostate.

We describe our initial experience of a method which develops the role of endoscopic surgery in the treatment of early prostatic carcinoma. An "extended" transurethral resection of the prostate (TURP) under ultrasound control reduces the prostatic tissue to a thin residual capsule suitable for subsequent transmural coagulation by endoscopic YAG laser. Twenty patients with early disease were entered into the pilot study. Three were excluded after staging (2 T0a and 1 with positive nodes on pelvioscopy-T2 N1 M0); 17 received a full course of treatment. Mean follow-up was 6 months (range 1-14). Two early patients with excessive residual tissue had initially positive biopsies and underwent second treatments with subsequently negative biopsies. Two patients continue to have positive biopsies and the rest are negative. No tumour has progressed and complications have been minimal. One patient experienced reduced frequency of erections and 1 required bladder neck incision for symptomatic bladder neck stenosis at routine follow-up endoscopy. There were no other effects on either potency or continence.

Adult↗

PubMed2005

Gastric pneumatosis after endoscopic argon plasma coagulation.

INTRODUCTION: Endoscopic argon plasma coagulation (APC) is gaining widespread usage but its risk is underreported. CLINICAL PICTURE: A 74-year-old man who received radical radiotherapy for gastric carcinoma 6 months ago was admitted for anaemia and maelena. Gastroscopy revealed haemorrhagic radiation gastritis. Endoscopic APC was performed but terminated when he complained of severe epigastric pain. Computed tomography scan showed gastric pneumatosis. TREATMENT: His pain subsided with a period of overnight rest and observation. OUTCOME: He continued to have 3 sessions of endoscopic APC at monthly intervals and at 10 months posttreatment, his haemoglobin remained stable at 11.1 g/dL. CONCLUSIONS: This case report highlights a complication of gastric pneumatosis and discusses the safe usage of this modality of endoscopic haemostasis. This is to increase cognisance of this potentially fatal complication among endoscopists.

Aged↗

PubMed1992

Transurethral incision of the prostate using the holmium:YAG laser.

Transurethral incisions of the prostate were made endoscopically in 5 dogs under a fluid medium using a holmium:YAG (Ho:YAG) laser operating at a wavelength of 2.1 microns and with delivery of 1.0 J/pulse in 15 Hz (15 W). Histopathologic examination of tissues collected immediately after surgery revealed irregular crevices outlined by a narrow zone of coagulative necrosis. Ulcerated fissures persisted at 5 and 7 days with the initial stages of epithelial regeneration partially re-epithelializing the ulcerated surfaces. A modest inflammatory response characterized by edema, hemorrhage, and a mixed inflammatory cell infiltrate was also associated with the laser incision sites at 5 and 7 days. Three weeks postlasing, the ulcerated surfaces of the fissures were completely re-epithelialized. At 5 weeks only a slight indentation persisted at the incision sites with minimal changes in the subjacent submucosa and prostatic glandular architecture. Although the results of these investigations are preliminary, we believe that the Ho:YAG laser warrants further clinical evaluation for treating patients with benign prostatic hyperplasia (BPH), urethral strictures, bladder neck contractures, and constrictions of the upper urinary tracts.

Aluminum Silicates↗

PubMed2000

Treatment of recurrent colorectal liver metastases by interstitial laser photocoagulation.

BACKGROUND: Hepatic resection improves survival in selected patients with colorectal liver metastases. The treatment of recurrent hepatic metastases after resection is controversial. Interstitial laser photocoagulation, performed under local anaesthesia, offers a minimally invasive option to repeat resection. The first series of patients with recurrent colorectal liver metastases treated with photo- coagulation is reported. METHODS: Nineteen patients (five women and 14 men, median age 57 (range 44-71) years) who developed recurrent colorectal liver metastases after hepatectomy (five with bilateral disease) were treated with photocoagulation between 1993 and 1997. Fifteen patients also received chemotherapy (14 systemic, one hepatic arterial) before photocoagulation. RESULTS: There were no major complications or deaths related to the treatment. Six patients developed minor complications related to the procedure but did not require any form of intervention. Median survival from commencement of photocoagulation was 16 (range 4-36) months. CONCLUSION: Photocoagulation is a safe, minimally invasive therapy that may be used as an adjunct to chemotherapy and repeat resection in the treatment of recurrent colorectal liver metastases, and may lead to improved survival.

Adult↗

PubMed1988

Low power interstitial Nd YAG laser photocoagulation in normal and neoplastic rat colon.

The effects of low power (1-2 Watts), long exposure (30-400 seconds), interstitial Nd YAG laser therapy on dimethylhydrazine induced rat colonic neoplasms and normal rat colon have been studied. After a single exposure with appropriate laser parameters, dimethylhydrazine induced rat colonic neoplasms underwent coagulative necrosis, sloughed off over a four day period, and left an ulcer which healed within 28 days. Inadequate laser energy resulted in incomplete tumour necrosis whilst excessive laser power or energy increased the likelihood of perforation. Treatment of normal colon with 1 Watt for 30 seconds or longer resulted in coagulative damage which healed by granulation. Mean colonic bursting pressures were significantly decreased one hour after treatment with 1 Watt for 75 or 100 seconds compared with untreated colon (p less than 0.05 and p less than 0.001 respectively) but not in colon treated with 1 Watt for 30 or 50 seconds. In animals treated with 1 Watt for 100 seconds mean bursting pressures were significantly lower than untreated animals when the animals were killed two, four, and seven days after lasering (p less than 0.001 in each case) but not in animals killed at 11, 17, or 21 days. The technique may be of value in the treatment of some inoperable colorectal cancers and sessile polyps in man.

Animals↗

PubMed1992

[Hysteroscopically guided endometrial destruction in the treatment of menorrhagia].

Until recently, hysterectomy has been the alternative method of treatment in cases of premenopausal menorrhagia where it has not proved possible to obtain satisfactory regulation of the haemorrhage by medical means. Within recent years, a series of hysteroscopic methods have been developed for selective destruction of the endometrium by means of neodymium-laser, electroresection and coagulation. Compared with hysterectomy, hysteroscopic destruction of the endometrium appears to be a much more rapid, simpler and cheaper form of treatment of menorrhagia and appears to be associated with considerably fewer complications. The duration of hospitalization and the period of convalescence can be reduced considerably but, primarily, a large group of women can avoid hysterectomy. As yet, no controlled investigations of selective destruction of the endometrium as compared with conventional hysterectomy are available. There are no comparative investigations of the different methods nor of the long-term sequelae after destruction of the endometrium. This method of treatment has hitherto only been employed to a limited extent in Denmark. Coordination of the activities in this field in connection with establishing this form of treatment in Denmark should be encouraged.

Dilatation and Curettage↗

PubMed1990

Outcome of iatrogenic choroidal neovascularisation in sickle cell disease.

Choroidal neovascularisation developed in 62/66 (94%) eyes followed up for a mean period of 11.2 years after treatment with xenon arc feeder vessel coagulation for proliferative sickle retinopathy (PSR). In 27 eyes the neovascularisation was chorioretinal alone and in 35 eyes choriovitreal. Chorioretinal neovascularisation (CRN) was a benign complication but may convert to choriovitreal neovascularisation (CVN). Late sequelae of CVN included vitreous haemorrhage, posterior vitreous face fibrosis, and tractional retinal detachment. Visual loss (of greater than or equal to 3 Snellen lines for greater than or equal to 3 months) occurred in nine eyes affected by choroidal neovascularisation, though because of other pathology this could not always be attributed to the choroidal neovascularisation. The incidence of visual loss in CVN affected eyes was significantly greater, by survival curve analysis, than in eyes affected by CRN alone. Permanent visual loss from tractional retinal detachment definitely attributable to CVN occurred in 2/35 (6%) eyes.

Adolescent↗

PubMed1990

A prospective study of infrared coagulation, injection and rubber band ligation in the treatment of haemorrhoids.

One hundred patients with non-prolapsing and one hundred with prolapsing haemorrhoids were allocated to receive conventional treatment (CT) by injection sclerotherapy or rubber band ligation, or infrared photocoagulation (IRC). Significantly more patients with nonprolapsing haemorrhoids were symptom free after IRC (81%) than CT (59%) at three months. (Chi2 = 4.4, p = 0.05). There was no significant difference in the outcome at 1 or 4 years. Likewise for prolapsing haemorrhoids, there was no significant difference in the outcome of IRC or CT at 3 months, one or 4 years. However, recurrence of prolapse was more common after IRC (54%) than rubber band ligation (RBL) (27%) at 1 year (Chi2 = 3.46, p less than 0.1). IRC was significantly less painful than CT (p less than 0.001). IRC is a safe, rapid, non-invasive alternative to CT, which is acceptable to the patient and give similar results, though RBL provides more rapid and longer lasting relief from prolapse.

Adult↗

PubMed1994

Light distribution of ocular endophotocoagulator probes and its surgical implications.

Ophthalmic endophotocoagulator probe cone angle affects the spot size, working distance, laser output power requirement, tissue exposure time, and uniformity of tissue irradiance, which all affect ease and safety of clinical use. The cone angle and irradiance distribution of several ophthalmic endophotocoagulator delivery systems were studied by directing the laser energy emitted by them on a CCD video sensor at several angles of incidence. The irradiances followed a Gaussian distribution. The measured irradiances were compared to a mathematical model of tissue irradiance that adjusted for the cone angle, probe-tissue distance, and angle of incidence. Using this model, laser irradiances produced by endophotocoagulator probes can be estimated under a wide variety of conditions. At highly oblique angles of incidence, wide-angle probes produce unexpectedly higher and uneven tissue irradiance. When numerous characteristics are considered, probes with a cone angle in the range of 10 degrees have many advantages over narrower or wider angle probes.

Fiber Optic Technology↗

PubMed1977

The role of axoplasmic transport in the pathogenesis of retinal cotton-wool spots.

Small retinal arterioles in the pig retina were occluded by argon laser photocoagulation and the morphology and topography of the resulting lesions studied by ophthalmoscopy, histology, and electron microscopy. Two days after laser coagulation ischaemic necrosis of the inner retina was observed in the territory of occluded arterioles, and swollen axon terminals packed with cytoplasmic organelles were found in the retinal nerve-fibre layer on the peripheral border of the infarcts and their border nearest to the disc. These swellings gave rise to localised zones of opacification (cotton-wool spots) at the borders of the retinal infarcts, and similar zones developed in relation to the laser burns. Amino-acid uptake and transport in retinal ganglion cells was studied in these animals by autoradiography following an intravitreal injection of tritiated leucine. When 3H-leucine was injected at the same time as laser coagulation and arteriolar occlusion, label became concentrated in the swollen axon-terminals on the peripheral aspect of 2-day-old infarcts but was absent from the terminals on the disc side of infarcts. The accumulation of 3H-leucine and organelles was attributed to interruption of orthograde axoplasmic transport. When 3H-leucine was injected into the vitreous 2 days prior to laser occlusion, label became distributed throughout the axoplasm and then accumulated in swollen axon terminals on both sides of infarcts after a further 2 days. An obstruction to both orthograde and retrograde axoplasmic flow was thus demonstrated. We concluded that cotton-wood spots should be redefined as accumulations of cytoplasmic debris in the retinal nerve-fibre layer caused by obstruction of orthograde or retrograde axoplasmic transport in ganglion cell axons.

Animals↗

PubMed1989

A personal experience in comparing three nonoperative techniques for treating internal hemorrhoids.

Infrared photocoagulation therapy was used on a total of 302 patients. Approximately 20% of the patients experienced minor bleeding; however, two required surgery, and 30% of the patients experienced discomfort during a 14-day period following the procedure. Good results were obtained in patients with first- and second-degree hemorrhoids. Heater probe coagulation therapy was conducted in a total of 264 patients. Good results were achieved in 90% of patients with first- and second-degree hemorrhoids, minor pain and bleeding occurred in approximately 10% of these patients, and one patient with third-degree hemorrhoids who was treated with this technique failed to respond and required surgery. Ultroid d.c. current therapy was utilized in 192 patients, and follow-up results were good in 95% of these cases. Minor bleeding occurred in four patients. It is concluded that all three techniques, performed on an outpatient basis with little or no sedation, are effective modalities for first- and second-degree hemorrhoids, but that Ultroid d.c. current therapy is associated with less discomfort and fewer complications and that Ultroid therapy may yield good results in some patients with third- or even fourth-degree hemorrhoids.

Hemorrhoids↗

PubMedDate not supplied

[Panretinal photocoagulation with argon laser--material from the Eye Clinic in Wroclaw in 1991-1994].

PURPOSE: To evaluate the results of PRK performed between 1990 and 1994 in Wroclaw University Eye Clinic. MATERIALS AND METHODS: PRK was performed in 630 eyes with: (1) PDR--451 immediately treated eyes (moderate PDR--184 eyes, with "high-risk" characteristics--227 eyes, PDR advanced--after cryopexion--40 eyes); (2) severe NPDR--119 eyes (with PDR in fellow eye or with ME) and (3) less severe DR--60 eyes treated with immediate or delayed, full or mild scatter coagulation (with macular edema, both eye moderate NPDR, other systemic risk factors). Follow-up treatment: Additional scatter or local photocoagulation was performed in 34 cases increasing activity of neovascularisation or increase in frequency/extend of vitreous hemorrhage. RESULTS: In a period 3 to 36 months of follow-up (mean period = 25 months) in the group of 451 eyes with PDR 28.2% of eyes showed visual improvement, 48.3% of eyes showed no change and 23.5% of eyes worsened. In the group of 119 eyes with severe NPRD 75.6% showed visual improvement and 24.4% showed no change. In the group of 60 eyes with less severe DR 27.8% showed improvement, 36.7% showed no change and 35.5% worsened. CONCLUSION: Our results are relatively good and in agreement with other studies.

Diabetic Retinopathy↗

PubMed1995

Ultrastructural alterations in heated canine myocardium.

BACKGROUND AND OBJECTIVE: The anisotropy factor of light scattering (g) (wavelength 632.8 nm) in heated myocardium decreases as a function of temperature, suggesting, on the basis of Mie theory of light scattering, formation of an increasing number of particles with diameters smaller than the incident wavelength. STUDY DESIGN/MATERIALS AND METHODS: To test this hypothesis, fresh myocardium was heated at constant temperatures between 37 degrees C and 75 degrees C for 1,000 s. Changes in size and number of granules generated by disintegrating organelles and sarcomeres were studied as a function of temperature by transmission electron microscopy, planimetry and particle counting. RESULTS: The mitochondria started to disintegrate at 45 degrees C and myofibrils between 45 degrees C and 50 degrees C into increasing numbers of small electron dense granules (diameter 50-200 nm), which correlated with the observed decrease of g from 0.93 +/- 0.02 (at room temperature to 45 degrees C) to 0.77 +/- 0.05 at 75 degrees C. CONCLUSION: The scattering coefficient microseconds of 161 +/- 33 cm-1 did not change significantly.

Actin Cytoskeleton↗

PubMed2003

[Prophylactic pan-coagulation from ischemic central vein occlusions? Practicability of the results from the Central Vein Occlusion Study Group].

PURPOSE: Central vein occlusions (CVO) with an avascular area of more than 10 optic-disc areas are classified as ischemic by the Central Vein Occlusion Study Group (CVOSG). For patients without neovascularizations (NV) clinical controls every 4 weeks during the first 6 months are recommended instead of prophylactic pancoagulation (PC). In this study we examined the practicability of this recommendation. PATIENTS AND METHODS: We analysed the records of 15 patients with ischemic CVO and no clinical signs of NV and no prophylactic PC retrospectively. All these patients developed a neovascular glaucoma (NVG) despite using the criteria of the CVOSG and were then treated with cyclophotocoagulation (CPC). RESULTS: The time between first presentation and CPC was 4.4+/-2.9 months. Of these patients 7 developed a NVG within 4 weeks after initial presentation. CONCLUSIONS: This study shows that NV and NVG may develop much faster than 4 weeks and can already be irreversible. Therefore it seems advisable to follow-up patients with increased risk factors even more frequently especially during the initial phase after CVO.

Aged↗

PubMed1992

Response of the retinal pigment epithelium to selective photocoagulation.

Multiple short argon laser pulses can coagulate the retinal pigment epithelium selectively, while sparing the adjacent neural retina and choroid; in contrast, continuous-wave laser irradiation typically damages the neural retina and choroid. The healing response to selective photocoagulation of the retinal pigment epithelium was studied in rabbits during a period of 4 weeks. The lesions were never visible ophthalmoscopically. During the healing period, the epithelium was reformed by a single sheet of hypertrophic retinal pigment epithelial cells. In contrast to continuous-wave photocoagulation, only minimal inflammatory response was found. Retinal pigment epithelial cells showed clear signs of viability, eg, phagocytized outer segments. The local edema in the photoreceptor layer and subretinal space found in the early stage disappeared when the blood-retinal barrier was reestablished. The choriocapillaris remained unaffected. No subsequent damage to the photoreceptors was found. This type of photocoagulation may be useful for retinal pigment epithelium-related diseases, eg, diffuse diabetic macular edema.

Animals↗

PubMed1994

Photodynamic therapy and cancer of the esophagus.

Esophageal carcinoma usually is diagnosed at an advanced, incurable stage. In patients with good operative risk, surgery is still considered the ideal treatment. Patients with coexisting major medical conditions in whom resective surgery is precluded may benefit from several therapeutic options, including photodynamic therapy (PDT) with porfimer sodium (Photofrin; manufactured by Lederle Parenterals, Carolina, Puerto Rico, under license from Quadra Logic Technologies, Inc, Vancouver, British Columbia, Canada), dilation, thermal destruction, Nd:YAG laser ablation, injection therapy, and placement of prosthetic tubes. Photodynamic therapy with porfimer sodium is thought to have a direct toxic effect on malignant cells via the production of singlet oxygen, which damages the microvasculature of the tumor and renders it ischemic. The 630 nm wavelength used for clinical PDT exhibits the greatest relative degree of light penetration into tissue, with corresponding activation of retained photosensitizer. The efficacy of PDT with porfimer sodium is closely related to stage of disease. It should be emphasized that PDT has been shown to be potentially curative in patients with early, noninvasive tumors of both squamous and glandular (adenocarcinoma) histologies. Eighty-three patients with esophageal carcinoma were treated using PDT. At presentation, 60% of patients had recurrence following previous radiotherapy or chemotherapy. Patients with less advanced disease had a better response to PDT with regard to relief of dysphagia and prolongation of survival. Photodynamic therapy was found to be more useful than Nd:YAG laser therapy for high, upper third lesions, especially circumferential ones. For tumors larger than 8 cm, PDT was twice as effective as Nd:YAG laser therapy in establishing prolonged lumen patency, especially for adenocarcinomas. Photodynamic therapy appears to have the added advantages of fewer treatments and less pain. The role of PDT in gastrointestinal malignancies continues to evolve.

Adenocarcinoma↗

PubMed1992

Thermal effects in tissues from combined simultaneous coaxial CO2 and Nd:YAG laser beams.

This study examines the depth of thermal coagulation and charring in swine liver, kidney cortex, tongue (inferior surface), skeletal muscle, inflated lung, and skin resulting from in vivo incision with simultaneous coaxial CO2 and Nd:YAG (1.064 microM) laser beams. At values of 20 w and 40 w, respectively, and at values of 30 w and 60 w, respectively, of combined CO2 and Nd:YAG laser radiation, coagulation depths determined histologically in liver were significantly greater (P less than 0.01) than in the other tissues and were significantly less in inflated lung (P less than 0.05) than in other tissues for the larger laser power settings employed. Coagulation depths achieved at 10 w and 20 w, respectively, and at 20 w and 40 w, respectively, of CO2 and Nd:YAG laser power were comparable to those obtained by other workers in liver and other relatively vascular tissues using a contact Nd:YAG laser tip. Charring depths obtained at power settings of 30 w (CO2) and 60 w (Nd:YAG) were greater in liver (P less than 0.001) than in all other tissues examined. Hemostasis during incision was achieved only for values of the ratio of CO2 to Nd:YAG laser power in the range 2-3 in the more vascular tissues, liver and kidney cortex, whereas hemostasis was achieved also in the lesser vascular tissues at higher values. These results strongly suggest the usefulness of combined simultaneous CO2 and Nd:YAG laser beams in surgery of the more vascular organs and tissues.

Animals↗