244 results on '"Parker, William H."'
Search Results
202. Range-wide morphological and anatomical variation in Larix laricina
- Author
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Dickinson, Timothy A. and Parker, William H.
- Published
- 1990
203. Analysis of variation in leaf and twig characters of Abies lasiocarpa and A. amabilis from north-coastal British Columbia
- Author
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Maze, Jack, Parker, William H., Bradfield, Gary E., and Lin, S.-C.
- Published
- 1979
204. Adaptive variation in Picea mariana from northwestern Ontario determined by short-term common environment tests
- Author
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Parker, William H., Charrette, Paul, and van Niejenhuis, Annette
- Subjects
BLACK spruce - Published
- 1994
- Full Text
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205. Some considerations when selecting young jack pine families using growth and form traits
- Author
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Parker, William H., Morris, Dave M., and Seabrook, Rod
- Published
- 1992
206. Variable-quality form in mature jack pine stands: quantification andrelationship with environmental factors
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Parker, William H. and Morris, Dave M.
- Subjects
FORESTS & forestry - Published
- 1992
207. Selection of Picea mariana for growing space efficiency
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Parker, William H. and Van Damme, Laird
- Published
- 1987
208. Vegetative phenology in a clonal seed orchard of Picea glauca and Picea mariana in northwestern Ontario
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Parker, William H. and O'Reilly, Conor
- Subjects
PHENOLOGY ,BIOLOGICAL variation - Published
- 1982
209. Adaptive variation in jack pine from north central Ontario determined by short-term common garden tests
- Author
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Parker, William H. and van Niejenhuis, Annette
- Subjects
FOREST management - Published
- 1996
210. PROGNOSTIC IMPORTANCE OF INTRAOPERATIVE RUPTURE OF MALIGNANT OVARIAN EPITHELIAL NEOPLASMS.
- Author
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Parker, William H. and Berek, Jonathan S.
- Published
- 1994
211. Join forces for cost-effective harmony
- Author
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Parker, William H., III and Ringer, Warren H.
- Published
- 1979
212. The Police Primer.
- Author
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Parker, William H.
- Subjects
POLICE ,PUBLIC opinion - Abstract
Focuses on the role of policemen in the community. Risk on their position; Prevalence of public opinion; Respect for the lawman.
- Published
- 1968
213. Optimal white spruce breeding zones for Ontario under current and future climates.
- Author
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Thomson, Ashley M., Crowe, Kevin A., and Parker, William H.
- Subjects
- *
WHITE spruce , *PLANT breeding research , *GENERAL circulation model , *FOREST productivity & climate , *AGRICULTURAL climatology , *SEEDS & climate , *FOREST regeneration , *PRINCIPAL components analysis , *PLANT reproduction - Abstract
Optimal breeding zones were developed for white spruce (Picea glauca (Moench) Voss) in Ontario under present and future climate conditions to examine potential shifts due to climate change. These zones were developed by (i) determining a set of candidate breeding zones based on the relationship between measured performance variables and climate and (ii) employing a decision support model to select subsets of breeding zones that maximize geographic coverage subject to a constraint on the maximum number of zones. Current optimal breeding zones were based on 1961–1990 climate normals, and future breeding zones were based on three general circulation model (CGCM2, HADCM3, and CSIRO) predictions of 2041–2070 climate. Based on a maximum adaptive distance of 2.0 least significant difference values between sites within zones, 14 zones were required to cover the Ontario range of white spruce for the 1961–1990 data. Compared with breeding zones of other boreal conifers, current optimal breeding zones for white spruce were quite large, spanning up to 3° latitude and 10°–12° longitude and indicating large distances of effective seed transfer. Of the three general circulation models used to simulate future climate, HADCM3 B2 and CGCM2 B2 predicted 2041–2070 breeding zones that largely coincide with 1961–1990 zones. In contrast, CSIRO B2 indicated much narrower 2041–2070 breeding zones. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
214. Boreal forest provenance tests used to predict optimal growth and response to climate change: 2. Black spruce.
- Author
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Thomson, Ashley M., Riddell, Claire L., and Parker, William H.
- Subjects
- *
TAIGAS , *EFFECT of global warming on plants , *PROVENANCE trials , *BLACK spruce , *TREE growth , *RESEARCH methodology , *CONTOURS (Cartography) , *TRANSFER functions , *LAKES - Abstract
Height, diameter, and survival data were obtained from 20 range-wide black spruce (Picea mariana (Mill.) BSP) provenance trials established from 1973 to 1977. Population response functions based on February minimum temperatures were developed for 23 Ontario and Great Lakes states provenances to predict climate values maximizing height growth for individual seed sources. Site transfer functions based on February maximum temperatures and May maximum temperatures were developed for five test sites to predict climate values maximizing height growth for test locations. Contour lines representing optimal performance were fitted to current (1961–1990) and future (2041–2070) climate grids. For black spruce seed sources from the east of Lake Superior and Lake Huron, optimal height growth was achieved between 45° and 47°N; for the western sources optimal performance moved north between 46° and 48°N. In eastern Ontario, height growth of northern sources may increase with transfer to warmer environments and with future temperature increases. Central sources are currently growing at or close to optimum and will be negatively affected by increased future temperatures. Southern sources may currently benefit from transfer to cooler environments, and the effects of global warming may cause significant height growth loss and the potential extirpation of local populations. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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215. Investigation of limestone ecotypes of white spruce based on a provenance test series.
- Author
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Lesser, Mark R., Cherry, Marilyn, and Parker, William H.
- Subjects
- *
LIMESTONE , *WHITE spruce , *PROVENANCE trials , *FORESTRY research - Abstract
Previous laboratory and field studies have presented evidence for the existence of limestone ecotypes in white spruce (Picea glauca (Moench) Voss). Remeasurements of the range-wide 410 series of provenance trials were used for further evaluation of the existence of these ecotypes. In 2001, heights were measured of 23 provenances grown at four test sites in Ontario, all located south of 46°N. Bedrock classification for test sites and provenances by limestone or non-limestone parent material was done using a 1993 data set of the Ontario Geological Survey. Analysis of variance revealed significant differences among test sites and provenances only. No significant interactions consistent with the existence of limestone ecotypes were detected. This finding is in contrast to that of an earlier field study that detected a strong interaction between test site and provenance bedrock type (p < 0.001). Examination of the relative performance of individual provenances from limestone and non-limestone bedrock types revealed differences in performance at the four different test sites but few instances supporting the existence of limestone ecotypes. Although these more recent results generally support a pattern of between-stand variation in southern Ontario, they do not disprove the existence of limestone ecotypes, owing to the nature of the 410-series test design and the classification of provenances according to bedrock type instead of actual soil analyses. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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216. Capsule summary: Hum Reprod.
- Author
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Parker, William H.
- Published
- 2007
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217. A journal of evidence
- Author
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Olive, David L. and Parker, William H.
- Published
- 1997
- Full Text
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218. Edited by M.D., Ph.D. Raymond H. Kaufman Sebastian Faro Benign Diseases of the vulva and vagina 4th edition 1994 Mosby-Year Book St. Louis 399 pages, 617 illustrations, 18 color, $99.00
- Author
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Parker, William H.
- Published
- 1994
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219. Will Artificial Intelligence Be "Better" Than Humans in the Management of Syncope?
- Author
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Dipaola F, Gebska MA, Gatti M, Levra AG, Parker WH, Menè R, Lee S, Costantino G, Barsotti EJ, Shiffer D, Johnston SL, Sutton R, Olshansky B, and Furlan R
- Abstract
Clinical decision-making regarding syncope poses challenges, with risk of physician error due to the elusive nature of syncope pathophysiology, diverse presentations, heterogeneity of risk factors, and limited therapeutic options. Artificial intelligence (AI)-based techniques, including machine learning (ML), deep learning (DL), and natural language processing (NLP), can uncover hidden and nonlinear connections among syncope risk factors, disease features, and clinical outcomes. ML, DL, and NLP models can analyze vast amounts of data effectively and assist physicians to help distinguish true syncope from other types of transient loss of consciousness. Additionally, short-term adverse events and length of hospital stay can be predicted by these models. In syncope research, AI-based models shift the focus from causality to correlation analysis between entities. This prompts the search for patterns rather than defining a hypothesis to be tested a priori. Furthermore, education of students, doctors, and health care providers engaged in continuing medical education may benefit from clinical cases of syncope interacting with NLP-based virtual patient simulators. Education may be of benefit to patients. This article explores potential strengths, weaknesses, and proposed solutions associated with utilization of ML and DL in syncope diagnosis and management. Three main topics regarding syncope are addressed: 1) clinical decision-making; 2) clinical research; and 3) education. Within each domain, we question whether "AI will be better than humans," seeking evidence to support our objective inquiry., Competing Interests: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Published
- 2024
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220. COVID-19 and postural tachycardia syndrome: a case series.
- Author
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Parker WH, Moudgil R, Wilson RG, Tonelli AR, Mayuga KA, and Singh TK
- Abstract
Background: Postural tachycardia syndrome (PTS) is a novel identified sequela of COVID-19 infection. This observational study describes clinical presentation, testing, and treatment response in seven patients diagnosed with PTS following COVID-19 infection., Case Summary: A total of seven active patients (three collegiate athletes, one recreational athlete, two registered nurses, one hospitality employee), age 24 ± 6 years, and six females were followed for a mean of 152 ± 105 days after contracting COVID-19. Tilt table was performed to establish the diagnosis. The most common presenting symptoms were palpitations (7/7), dyspnoea (6/7), and gastrointestinal complaints (5/7). One patient required hospitalization for symptom management. The mean latency of PTS onset following COVID-19 was 21 ± 15 days. Electrocardiograms (ECGs) demonstrated sinus rhythm in all patients, one with resting sinus tachycardia. Echocardiogram demonstrated normal systolic and diastolic left ventricular function in all patients. On tilt table testing, baseline heart rate (HR) was 72 ± 12 with maximum HR reaching 136 ± 13. Six of seven patients failed to respond to supportive therapy alone, and two patients failed medical management with ivabradine, midodrine, and/or metoprolol. Of three severely symptomatic patients, two demonstrated some degree of clinical recovery with intravenous immunoglobulin (IVIG)., Discussion: This novel case series describes the development of PTS in the context of COVID-19 infection. Severity of symptoms and response to treatment was heterogeneous. Interestingly, patients were poorly responsive to traditional PTS treatments, but IVIG showed potential as a possible therapeutic strategy for refractory PTS in two patients, particularly following COVID-19 infection., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)
- Published
- 2021
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221. Quality of Life after Laparoscopic and Open Abdominal Myomectomy.
- Author
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Rodriguez-Triana VM, Kwan L, Kelly M, Olson TH, and Parker WH
- Subjects
- Female, Humans, Prospective Studies, Quality of Life, Laparoscopy, Uterine Myomectomy, Uterine Neoplasms surgery
- Abstract
Study Objective: To evaluate the baseline and postoperative changes in quality of life and symptom-severity scores in women undergoing laparoscopic or open abdominal myomectomy for symptomatic myomas., Design: Prospective cohort study of patients choosing myomectomy for symptomatic uterine myomas., Setting: Academic medical center., Patients: A total of 143 women enrolled in the study. Of these, 80 women completed both a preoperative questionnaire and at least 1 postoperative questionnaire between 6 and 27 months after surgery., Interventions: A total of 52 women had open abdominal myomectomy, and 28 had laparoscopic myomectomy between October 2014 and September 2017., Measurements and Main Results: The results of the Uterine Fibroid Symptom and Health-Related Quality-of-Life Questionnaire were compared before and after laparoscopic or open myomectomy. Women undergoing open abdominal myomectomy had larger and more numerous myomas than women undergoing laparoscopic myomectomy. Baseline quality-of-life scores were less adversely affected for women having laparoscopic myomectomy (mean [standard deviation], 57 [24] laparoscopic vs 43 [19] open abdominal, p = .01). However, baseline symptom-severity scores were statistically similar (49 [22] for laparoscopic and 57 [20] for open abdominal, p = .08) approaches. Six to 12 months after surgery, both open abdominal and laparoscopic surgeries provided excellent and similar improvements in symptom-severity and quality of life (postoperative symptoms severity scores, mean [standard deviation], 20 [14] laparoscopic vs 13 [11] open abdominal, p = .24 and quality-of-life scores, mean [standard deviation], 91 [16] laparoscopic vs 88 [17] open abdominal, p = .49). These improvements were sustained for women who returned questionnaires up to 27 months of follow-up., Conclusion: Women with symptomatic myomas have a compromised quality of life, and they experience a similarly dramatic improvement in quality of life and decrease in symptom-severity after both laparoscopic and open abdominal myomectomies., (Copyright © 2020 AAGL. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
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222. Vaginal Hysterectomy: Historical Footnote or Viable Route?
- Author
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Parker WH and Levy B
- Subjects
- Female, Humans, Uterus, Hysterectomy, Hysterectomy, Vaginal
- Published
- 2020
- Full Text
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223. Massive cotyledenoid leiomyoma treated with uterine-conserving surgery.
- Author
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Parker WH, Turner R, Schwimer S, and Foshag L
- Abstract
Objective: To describe and illustrate a massive cotyledenoid leiomyoma treated with uterine-conserving surgery., Design: Case report., Setting: Medical center., Patients: A 39-year-old woman with a large abdominal mass and a magnetic resonance imaging scan showing a 28-cm multi-lobulated mass., Interventions: Laparotomy and myomectomy., Main Outcome Measures: Recurrence and need for repeat surgery., Results: No recurrence at 8 years of follow-up., Conclusions: Cotyledonoid leiomyomas are rare. These benign tumors may be suspected preoperatively based on MRI appearance. Frozen section suggests a benign process and uterine-conserving surgery may be successfully accomplished., (© 2020 The Author(s).)
- Published
- 2020
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224. Indications for morcellation in gynecologic surgery.
- Author
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Parker WH
- Subjects
- Delayed Diagnosis, Female, Genital Neoplasms, Female diagnosis, Genital Neoplasms, Female pathology, Genital Neoplasms, Female prevention & control, Humans, Hysterectomy adverse effects, Intraoperative Complications etiology, Intraoperative Complications prevention & control, Laparoscopy adverse effects, Leiomyoma pathology, Leiomyosarcoma pathology, Leiomyosarcoma prevention & control, Leiomyosarcoma surgery, Neoplasm Recurrence, Local prevention & control, Neoplasm, Residual prevention & control, Patient Safety, Tumor Burden, Uterine Myomectomy adverse effects, Contraindications, Procedure, Genital Neoplasms, Female surgery, Hysterectomy instrumentation, Leiomyoma surgery, Morcellation adverse effects, Uterine Myomectomy instrumentation
- Abstract
Purpose of Review: Minimally invasive gynecologic procedures, in particular laparoscopic hysterectomy and myomectomy, often require tissue morcellation., Recent Findings: Whether morcellated or not, myometrial cells can be found in the abdomen and pelvis after either laparoscopic or open myomectomy. Following morcellation, careful inspection for and removal of tissue fragments and copious irrigation and suctioning of fluid can remove residual tissue and cells without the use of containment bags. The dogma of not 'cutting-through' cancer is not correct for many surgical specialties and irrelevant with regards to leiomyosarcoma (LMS) and minimally invasive gynecologic surgery. Eliminating residual disease in the pelvis and abdomen should be the goal of myomectomy or hysterectomy., Summary: Morcellation of excised tissue is necessary for many women with symptomatic fibroids who choose to undergo laparoscopic myomectomy or hysterectomy. LMS is an uncommon disease, with a poor prognosis due to early hematogenous metastasis to lung, bone and liver. Preoperatively, it is often difficult to differentiate from benign fibroids. LMS has a high propensity for local recurrence despite performance of total hysterectomy. Efforts to remove all tissue and cells from the pelvis and abdomen should be the goal of minimally invasive surgery with morcellation.
- Published
- 2018
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225. Intracellular ascorbate tightens the endothelial permeability barrier through Epac1 and the tubulin cytoskeleton.
- Author
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Parker WH, Rhea EM, Qu ZC, Hecker MR, and May JM
- Subjects
- Cell Line, Cyclic AMP metabolism, Cyclic AMP-Dependent Protein Kinases metabolism, Cytoskeleton physiology, Human Umbilical Vein Endothelial Cells, Humans, Microtubules metabolism, Nitric Oxide metabolism, Oxidative Stress physiology, Permeability, Ascorbic Acid metabolism, Cytoskeleton metabolism, Endothelium metabolism, Endothelium physiology, Guanine Nucleotide Exchange Factors metabolism, Tubulin metabolism
- Abstract
Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species., (Copyright © 2016 the American Physiological Society.)
- Published
- 2016
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226. Ascorbic acid prevents VEGF-induced increases in endothelial barrier permeability.
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Ulker E, Parker WH, Raj A, Qu ZC, and May JM
- Subjects
- Antioxidants pharmacology, Human Umbilical Vein Endothelial Cells, Humans, Nitric Oxide physiology, Permeability, Ascorbic Acid pharmacology, Endothelium, Vascular physiology, Vascular Endothelial Growth Factor A physiology
- Abstract
Vascular endothelial growth factor (VEGF) increases endothelial barrier permeability, an effect that may contribute to macular edema in diabetic retinopathy. Since vitamin C, or ascorbic acid, can tighten the endothelial permeability barrier, we examined whether it could prevent the increase in permeability due to VEGF in human umbilical vein endothelial cells (HUVECs). As previously observed, VEGF increased HUVEC permeability to radiolabeled inulin within 60 min in a concentration-dependent manner. Loading the cells with increasing concentrations of ascorbate progressively prevented the leakage caused by 100 ng/ml VEGF, with a significant inhibition at 13 µM and complete inhibition at 50 µM. Loading cells with 100 µM ascorbate also decreased the basal generation of reactive oxygen species and prevented the increase caused by both 100 ng/ml VEGF. VEGF treatment decreased intracellular ascorbate by 25%, thus linking ascorbate oxidation to its prevention of VEGF-induced barrier leakage. The latter was blocked by treating the cells with 60 µM L-NAME (but not D-NAME) as well as by 30 µM sepiapterin, a precursor of tetrahydrobiopterin that is required for proper function of endothelial nitric oxide synthase (eNOS). These findings suggest that VEGF-induced barrier leakage uncouples eNOS. Ascorbate inhibition of the VEGF effect could thus be due either to scavenging superoxide or to peroxynitrite generated by the uncoupled eNOS, or more likely to its ability to recycle tetrahydrobiopterin, thus avoiding enzyme uncoupling in the first place. Ascorbate prevention of VEGF-induced increases in endothelial permeability opens the possibility that its repletion could benefit diabetic macular edema.
- Published
- 2016
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227. U.S. Food and Drug Administration's Guidance Regarding Morcellation of Leiomyomas: Well-Intentioned, But Is It Harmful for Women?
- Author
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Parker WH, Kaunitz AM, Pritts EA, Olive DL, Chalas E, Clarke-Pearson DL, and Berek JS
- Subjects
- Female, Humans, Hysterectomy methods, Leiomyoma pathology, Leiomyosarcoma surgery, Morcellation instrumentation, United States, United States Food and Drug Administration, Uterine Myomectomy methods, Uterine Neoplasms pathology, Leiomyoma surgery, Leiomyosarcoma pathology, Morcellation adverse effects, Neoplasm Seeding, Practice Guidelines as Topic, Uterine Neoplasms surgery
- Abstract
The U.S. Food and Drug Administration (FDA) is warning against the use of laparoscopic power morcellators in the majority of women undergoing myomectomy or hysterectomy for the treatment of leiomyomas because of the concern for inadvertent spread of tumor cells if an undiagnosed cancer were present. The authors, representing a 45-member review group, reviewed the current literature to formulate prevalence rates of leiomyosarcoma in women with presumed leiomyomas and to asses reliable data regarding patient survival after morcellation. The authors disagree with the FDA's methodology in reaching their conclusion and provide clinical recommendations for care of women with leiomyomas who are planning surgery.
- Published
- 2016
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228. Outcome of occult uterine leiomyosarcoma after surgery for presumed uterine fibroids: a systematic review.
- Author
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Pritts EA, Parker WH, Brown J, and Olive DL
- Subjects
- Female, Humans, Outcome Assessment, Health Care, Risk Assessment, Uterine Myomectomy instrumentation, Uterine Myomectomy methods, Uterine Neoplasms pathology, Uterine Neoplasms surgery, Leiomyoma etiology, Leiomyoma prevention & control, Leiomyosarcoma pathology, Leiomyosarcoma surgery, Postoperative Complications etiology, Postoperative Complications prevention & control, Uterine Myomectomy adverse effects
- Abstract
There is concern that morcellation of occult leiomyosarcomas during surgery to treat presumed myomas may substantially worsen patient outcome. We reviewed the existing medical literature to better understand whether such a risk was demonstrable and, if so, what the magnitude of that risk might be. We identified 4864 articles initially, of which 60 were evaluated in full. Seventeen were found to have outcomes information and are included in this review. Six studies addressed the question of whether morcellation of occult leiomyosarcomas resulted in inferior outcomes as compared with en bloc uterine and tumor removal. In these 6 studies, results suggested that en bloc removal may result in improved survival and less recurrence; however, the data are highly biased and of poor quality. There is no reliable evidence that morcellation, power or otherwise, substantially results in tumor upstaging. There is no evidence from these 17 studies that power morcellation differs in any way from other types of morcellation or even simple myomectomy insofar as patient outcome. Whether electromechanical morcellation poses a unique danger to the patient with occult leiomyosarcoma is an unanswered question and one clearly in need of more extensive investigation before conclusions are drawn and policies created., (Copyright © 2015 AAGL. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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229. Surgical management of leiomyomas for fertility or uterine preservation.
- Author
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Falcone T and Parker WH
- Subjects
- Female, Humans, Hysterectomy methods, Hysteroscopy, Laparoscopy, Laparotomy, Leiomyoma diagnosis, Preoperative Care, Robotics, Uterine Neoplasms diagnosis, Uterus, Fertility Preservation, Leiomyoma surgery, Uterine Neoplasms surgery
- Abstract
Leiomyomas are the most common pelvic tumors in women. These tumors are not always symptomatic but can cause abnormal uterine bleeding and anemia, pelvic pressure and pain, urinary frequency, and adverse reproductive outcomes-symptoms that can diminish the quality of life of women. Myomectomy is the primary treatment modality for women with symptomatic leiomyomas who are of reproductive age and desire future fertility. Myomectomy can significantly improve symptoms and quality of life and, in some clinical situations, improve reproductive outcomes. There are robust surgical outcome data supporting the use of a minimally invasive approach such as laparoscopy and hysteroscopy over laparotomy. Perioperative outcomes and return to normal activity are significantly better with a minimally invasive approach. Reproductive outcomes are not adversely affected. Detailed preoperative imaging is required for minimally invasive procedures to be successful. There are several evidence-based techniques that can be used to reduce blood loss during surgery. The role of robotic technology in enhancing surgical outcomes has not been clearly defined.
- Published
- 2013
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230. Long-term mortality associated with oophorectomy compared with ovarian conservation in the nurses' health study.
- Author
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Parker WH, Feskanich D, Broder MS, Chang E, Shoupe D, Farquhar CM, Berek JS, and Manson JE
- Subjects
- Aged, Cardiovascular Diseases mortality, Cause of Death, Cohort Studies, Female, Humans, Middle Aged, Prospective Studies, Risk Factors, Time Factors, Hysterectomy mortality, Ovariectomy mortality
- Abstract
Objective: To report long-term mortality after oophorectomy or ovarian conservation at the time of hysterectomy in subgroups of women based on age at the time of surgery, use of estrogen therapy, presence of risk factors for coronary heart disease, and length of follow-up., Methods: This was a prospective cohort study of 30,117 Nurses' Health Study participants undergoing hysterectomy for benign disease. Multivariable adjusted hazard ratios for death from coronary heart disease, stroke, breast cancer, epithelial ovarian cancer, lung cancer, colorectal cancer, total cancer, and all causes were determined comparing bilateral oophorectomy (n=16,914) with ovarian conservation (n=13,203)., Results: Over 28 years of follow-up, 16.8% of women with hysterectomy and bilateral oophorectomy died from all causes compared with 13.3% of women who had ovarian conservation (hazard ratio 1.13, 95% confidence interval 1.06-1.21). Oophorectomy was associated with a lower risk of death from ovarian cancer (four women with oophorectomy compared with 44 women with ovarian conservation) and, before age 47.5 years, a lower risk of death from breast cancer. However, at no age was oophorectomy associated with a lower risk of other cause-specific or all-cause mortality. For women younger than 50 years at the time of hysterectomy, bilateral oophorectomy was associated with significantly increased mortality in women who had never used estrogen therapy but not in past and current users: assuming a 35-year lifespan after oophorectomy: number needed to harm for all-cause death=8, coronary heart disease death=33, and lung cancer death=50., Conclusions: Bilateral oophorectomy is associated with increased mortality in women aged younger than 50 years who never used estrogen therapy and at no age is oophorectomy associated with increased survival., Level of Evidence: I.
- Published
- 2013
- Full Text
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231. The utility of MRI for the surgical treatment of women with uterine fibroid tumors.
- Author
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Parker WH
- Subjects
- Adult, Endometriosis pathology, Female, Humans, Middle Aged, Sarcoma pathology, Treatment Outcome, Uterus pathology, Leiomyoma pathology, Leiomyoma surgery, Magnetic Resonance Imaging, Uterine Neoplasms pathology, Uterine Neoplasms surgery
- Abstract
Determination of the reasonable treatment options and the appropriate clinical treatment of women with uterine fibroid tumors often depends on the ability of imaging modalities to accurately detect and localize fibroid tumors. Magnetic resonance imaging (MRI) gives the most complete evaluation (sizes, positions, number) of submucous, intramural, and subserosal myomas and is the most sensitive modality for the detection of small fibroid tumors. MRI allows the evaluation of fibroid tumor proximity to the bladder, rectum, and endometrial cavity, helps define what can be expected at surgery, and may help the gynecologist avoid missing fibroid tumors during surgery. MRI can also make the diagnosis of adenomyosis reliably and may be able to identify uterine sarcoma when present., (Copyright © 2012 Mosby, Inc. All rights reserved.)
- Published
- 2012
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232. Gynecologic surgery and the management of hemorrhage.
- Author
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Parker WH and Wagner WH
- Subjects
- Anemia drug therapy, Blood Coagulation Disorders prevention & control, Blood Transfusion, Drug-Related Side Effects and Adverse Reactions, Female, Humans, Medical Records, Pharmaceutical Preparations administration & dosage, Postoperative Hemorrhage therapy, Preoperative Care, Blood Loss, Surgical prevention & control, Gynecologic Surgical Procedures adverse effects
- Abstract
Surgical blood loss of more than 1000 mL or blood loss that requires a blood transfusion usually defines intraoperative hemorrhage. Intraoperative hemorrhage has been reported in 1% to 2% of hysterectomy studies. Preoperative evaluation of the patient can aid surgical planning to help prevent intraoperative hemorrhage or prepare for the management of hemorrhage, should it occur. To this effect, the medical and medication history and use of alternative medication must be gathered. This article discusses the methods of preoperative management of anemia, including use of iron, recombinant erythropoietin, and gonadotropin-releasing hormone agonists. The authors have also reviewed the methods of intraoperative and postoperative management of bleeding., (Copyright 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
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233. Risk factors for uterine rupture after laparoscopic myomectomy.
- Author
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Parker WH, Einarsson J, Istre O, and Dubuisson JB
- Subjects
- Electrosurgery adverse effects, Female, Gynecologic Surgical Procedures adverse effects, Gynecologic Surgical Procedures methods, Humans, Laparoscopy methods, Pregnancy, Risk Factors, Wound Healing, Laparoscopy adverse effects, Leiomyoma surgery, Suture Techniques adverse effects, Uterine Neoplasms surgery, Uterine Rupture etiology
- Abstract
Case reports for uterine rupture subsequent to laparoscopic myomectomy were reviewed to determine whether common causal factors could be identified. Published cases were identified via electronic searches of PubMed, Google Scholar, and hand searches of references, and unpublished cases were obtained via E-mail queries to the AAGL membership and AAGL Listserve participants. Nineteen cases of uterine rupture after laparoscopic myomectomy were identified. The removed myomas ranged in size from 1 through 11 cm (mean, 4.5 cm). Only 3 cases involved multilayered closure of uterine defects. Electrosurgery was used for hemostasis in all but 2 cases. No plausible contributing factor could be found in one case [corrected]. It seems reasonable for surgeons to adhere to techniques developed for abdominal myomectomy including limited use of electrosurgery and multilayered closure of the myometrium. Nevertheless, individual wound healing characteristics may predispose to uterine rupture., (Copyright © 2010 AAGL. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
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234. Understanding errors during laparoscopic surgery.
- Author
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Parker WH
- Subjects
- Adolescent, Adult, Cognition, Endometriosis surgery, Female, Gynecologic Surgical Procedures education, Humans, Iliac Vein injuries, Intraoperative Complications prevention & control, Pelvic Pain etiology, Pelvic Pain surgery, Perception, Rectum injuries, Touch, Ureter injuries, Uterine Artery injuries, Vision, Ocular, Gynecologic Surgical Procedures adverse effects, Laparoscopy adverse effects, Medical Errors prevention & control
- Abstract
Complications may occur during laparoscopic surgery, even with a skilled surgeon and under ideal circumstances; human error is inevitable. Videotaped procedures from malpractice cases are evaluated to ascertain potential contributing cognitive factors, systems errors, equipment issues, and surgeon training. Situation awareness and principles derived from aviation crew resource management may be adapted to help avoid systems error. The current process of surgical training may need to be reconsidered., (Copyright 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
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235. Effect of bilateral oophorectomy on women's long-term health.
- Author
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Parker WH, Jacoby V, Shoupe D, and Rocca W
- Subjects
- Affect, Decision Making, Female, Health Status, Hip Fractures etiology, Humans, Middle Aged, Osteoporosis complications, Ovariectomy adverse effects, Quality of Life, Risk Assessment, Sexuality, Time Factors, Treatment Outcome, Women's Health, Hysterectomy methods, Ovariectomy methods, Ovary surgery
- Abstract
Bilateral oophorectomy at the time of hysterectomy for benign disease is commonly practiced in order to prevent the subsequent development of ovarian cancer or other ovarian pathology that might require additional surgery. At present, bilateral oophorectomy is performed in 78% of women aged between 45 and 64 years having a hysterectomy, and a total of approximately 300,000 prophylactic oophorectomies are performed in the USA every year. Estrogen deficiency resulting from pre- and post-menopausal oophorectomies has been associated with higher risks of coronary heart disease, stroke, hip fracture, Parkinsonism, dementia, cognitive impairment, depression and anxiety in many studies. While ovarian cancer accounts for 14,800 deaths per year in the USA, coronary heart disease accounts for 350,000 deaths per year. In addition, 100,000 cases of dementia may be attributable annually to prior bilateral oophorectomy. At present, observational studies suggest that bilateral oophorectomy may do more harm than good. In women who are not at high risk of developing ovarian or breast cancer, removing the ovaries at the time of hysterectomy should be approached with caution.
- Published
- 2009
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- View/download PDF
236. Ovarian conservation at the time of hysterectomy and long-term health outcomes in the nurses' health study.
- Author
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Parker WH, Broder MS, Chang E, Feskanich D, Farquhar C, Liu Z, Shoupe D, Berek JS, Hankinson S, and Manson JE
- Subjects
- Adult, Disease-Free Survival, Female, Follow-Up Studies, Humans, Middle Aged, Nurses statistics & numerical data, Outcome Assessment, Health Care, Prospective Studies, Risk Assessment, Risk Factors, Survival Rate, Cardiovascular Diseases epidemiology, Hip Fractures epidemiology, Hysterectomy, Neoplasms epidemiology, Ovariectomy, Postoperative Complications
- Abstract
Objective: To report long-term health outcomes and mortality after oophorectomy or ovarian conservation., Methods: We conducted a prospective, observational study of 29,380 women participants of the Nurses' Health Study who had a hysterectomy for benign disease; 16,345 (55.6%) had hysterectomy with bilateral oophorectomy, and 13,035 (44.4%) had hysterectomy with ovarian conservation. We evaluated incident events or death due to coronary heart disease (CHD), stroke, breast cancer, ovarian cancer, lung cancer, colorectal cancer, total cancers, hip fracture, pulmonary embolus, and death from all causes., Results: Over 24 years of follow-up, for women with hysterectomy and bilateral oophorectomy compared with ovarian conservation, the multivariable hazard ratios (HRs) were 1.12 (95% confidence interval [CI] 1.03-1.21) for total mortality, 1.17 (95% CI 1.02-1.35) for fatal plus nonfatal CHD, and 1.14 (95% CI 0.98-1.33) for stroke. Although the risks of breast (HR 0.75, 95% CI 0.68-0.84), ovarian (HR 0.04, 95% CI 0.01-0.09, number needed to treat=220), and total cancers (HR 0.90, 95% CI 0.84-0.96) decreased after oophorectomy, lung cancer incidence (HR=1.26, 95% CI 1.02-1.56, number needed to harm=190), and total cancer mortality (HR=1.17, 95% CI 1.04-1.32) increased. For those never having used estrogen therapy, bilateral oophorectomy before age 50 years was associated with an increased risk of all-cause mortality, CHD, and stroke. With an approximate 35-year life span after surgery, one additional death would be expected for every nine oophorectomies performed., Conclusion: Compared with ovarian conservation, bilateral oophorectomy at the time of hysterectomy for benign disease is associated with a decreased risk of breast and ovarian cancer but an increased risk of all-cause mortality, fatal and nonfatal coronary heart disease, and lung cancer. In no analysis or age group was oophorectomy associated with increased survival.
- Published
- 2009
- Full Text
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237. Fibroids and infertility: an updated systematic review of the evidence.
- Author
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Pritts EA, Parker WH, and Olive DL
- Subjects
- Female, Fertility physiology, Gynecologic Surgical Procedures adverse effects, Gynecologic Surgical Procedures rehabilitation, Humans, Leiomyoma physiopathology, Postoperative Complications etiology, Postoperative Complications physiopathology, Pregnancy, Pregnancy Rate, Infertility, Female etiology, Leiomyoma complications, Leiomyoma surgery
- Abstract
Objective: To investigate the effect of fibroids on fertility and of myomectomy in improving outcomes., Design: Systematic literature review and meta-analysis of existing controlled studies., Setting: Private center for Reproductive endocrinology and infertility., Patient(s): Women with fibroids and infertility., Intervention(s): A systematic literature review, raw data extraction and data analysis., Main Outcome Measure(s): Clinical pregnancy rate, spontaneous abortion rate, ongoing pregnancy/live birth rate, implantation rate, and preterm delivery rate in women with and without fibroids, and in women who underwent myomectomy., Result(s): Women with subserosal fibroids had no differences in their fertility outcomes compared with infertile controls with no myomas, and myomectomy did not change these outcomes compared with women with fibroids in situ. Women with intramural fibroids appear to have decreased fertility and increased pregnancy loss compared with women without such tumors, but study quality is poor. Myomectomy does not significantly increase the clinical pregnancy and live birth rates, but the data are scarce. Fibroids with a submucosal component led to decreased clinical pregnancy and implantation rates compared with infertile control subjects. Removal of submucous myomas appears likely to improve fertility., Conclusion(s): Fertility outcomes are decreased in women with submucosal fibroids, and removal seems to confer benefit. Subserosal fibroids do not affect fertility outcomes, and removal does not confer benefit. Intramural fibroids appear to decrease fertility, but the results of therapy are unclear. More high-quality studies need to be directed toward the value of myomectomy for intramural fibroids, focusing on issues such as size, number, and proximity to the endometrium.
- Published
- 2009
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238. Elective oophorectomy in the gynecological patient: when is it desirable?
- Author
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Parker WH, Shoupe D, Broder MS, Liu Z, Farquhar C, and Berek JS
- Subjects
- Cardiovascular Diseases epidemiology, Cardiovascular Diseases etiology, Elective Surgical Procedures, Female, Humans, Hysterectomy methods, Ovarian Neoplasms epidemiology, Ovarian Neoplasms etiology, Risk Factors, Ovariectomy methods
- Abstract
Purpose of Review: Oophorectomy is electively performed in approximately 300,000 US women per year who are having hysterectomy for benign disease., Recent Findings: New studies have suggested that elective oophorectomy may not be advisable for the majority of women, as it may lead to a higher risk of death from cardiovascular disease and hip fracture, and may result in a higher incidence of dementia and Parkinson's disease. Women with known BRCA 1/2 germ-line mutations clearly benefit from oophorectomy after childbearing., Summary: Prophylactic oophorectomy should be undertaken with caution in the majority of women with an average risk of ovarian cancer who are having a hysterectomy for benign disease.
- Published
- 2007
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239. Uterine myomas: management.
- Author
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Parker WH
- Subjects
- Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Female, Fertility, Gonadotropin-Releasing Hormone agonists, Gonadotropin-Releasing Hormone antagonists & inhibitors, Gonadotropin-Releasing Hormone therapeutic use, Gynecologic Surgical Procedures adverse effects, Humans, Intrauterine Devices, Leiomyoma diagnosis, Leiomyoma therapy, Menopause physiology, Models, Biological, Myoma diagnosis, Obstetric Surgical Procedures adverse effects, Pregnancy, Premedication, Progesterone administration & dosage, Prognosis, Uterine Neoplasms diagnosis, Myoma therapy, Uterine Neoplasms therapy
- Abstract
Objective: To review the currently available literature regarding the current management alternatives available to women with uterine myomas., Design: Literature review of 198 articles pertaining to uterine myomas., Result(s): Many advances have been made in the management of uterine myomas. Watchful waiting; medical therapy; hysteroscopic myomectomy; endometrial ablation; laparoscopic myomectomy; abdominal myomectomy; abdominal, vaginal, and laparoscopic hysterectomy; uterine artery embolization; uterine artery occlusion; and focused ultrasound are now available., Conclusion(s): Many options are now available to women with uterine myomas. The presently available literature regarding the treatment of myomas is summarized.
- Published
- 2007
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240. Avoiding complications of laparoscopic surgery: lessons from cognitive science and crew resource management.
- Author
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Parker WH, Johns A, and Hellige J
- Subjects
- Adolescent, Adult, Awareness, Clinical Competence, Decision Making, Female, Genital Diseases, Female surgery, Humans, Malpractice legislation & jurisprudence, Medical Errors psychology, Risk Management, Videotape Recording legislation & jurisprudence, Cognitive Science, Gynecologic Surgical Procedures education, Laparoscopy, Medical Errors prevention & control, Postoperative Complications prevention & control
- Abstract
Complications may occur during laparoscopic surgery, even with a skilled surgeon and under ideal circumstances, because human error is inevitable. We reviewed videotaped procedures where malpractice was alleged and resolved in court to evaluate potential contributing factors. We evaluated possible sources of complications related to cognitive science, systems error, equipment issues, and surgeon selection and training. The way the human brain's hard-wiring shapes information processing, as well as perceptual learning, can influence the risk of surgical complications. Situation awareness and principles derived from aviation crew resource management may be adapted to help avoid systems error. The current process used to select gynecologic surgeons and the structure of surgical training may need to be reconsidered.
- Published
- 2007
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241. Etiology, symptomatology, and diagnosis of uterine myomas.
- Author
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Parker WH
- Subjects
- Adult, Body Weight, Estrogen Replacement Therapy adverse effects, Estrogens physiology, Female, Growth Substances physiology, Humans, Incidence, Leiomyoma diagnosis, Leiomyoma ethnology, Leiomyoma etiology, Leiomyoma genetics, Middle Aged, Myoma diagnosis, Myoma ethnology, Myoma genetics, Pregnancy, Progesterone physiology, Risk Factors, Sarcoma genetics, Smoking adverse effects, Uterine Neoplasms diagnosis, Uterine Neoplasms ethnology, Uterine Neoplasms genetics, Myoma etiology, Uterine Neoplasms etiology
- Abstract
Objective: To review the currently available literature regarding the biology, etiology, symptoms, and diagnosis of uterine myomas., Design: Literature review of 220 articles pertaining to uterine myomas., Result(s): Although uterine myomas presently are not well understood, many advances have been made in the understanding of the hormonal factors, genetic factors, growth factors, and molecular biology of these benign tumors. Prospective, longitudinal studies are underway to characterize the risk factors for their development. When needed, the position of myomas can be best imaged by sonohysterography or magnetic resonance imaging. Evidence suggests that only submucous myomas appear to interfere with fertility, and only very rarely do myomas effect pregnancy outcome., Conclusion(s): A summary of the available literature regarding the biology, etiology, symptomatology, and diagnosis of myomas shows that, although they are still not well understood, much has been learned about uterine myomas.
- Published
- 2007
- Full Text
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242. Ovarian conservation at the time of hysterectomy for benign disease.
- Author
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Parker WH, Broder MS, Liu Z, Shoupe D, Farquhar C, and Berek JS
- Subjects
- Adult, Aged, Aged, 80 and over, Breast Neoplasms etiology, Coronary Disease etiology, Estrogen Replacement Therapy adverse effects, Estrogen Replacement Therapy mortality, Female, Hip Fractures etiology, Humans, Markov Chains, Middle Aged, Ovarian Neoplasms prevention & control, Sensitivity and Specificity, Stroke etiology, Survivors, Hysterectomy, Ovariectomy adverse effects, Ovariectomy mortality
- Abstract
Objective: Prophylactic oophorectomy is often recommended concurrent with hysterectomy for benign disease. The optimal age for this recommendation in women at average risk for ovarian cancer has not been determined., Methods: Using published age-specific data for absolute and relative risk, both with and without oophorectomy, for ovarian cancer, coronary heart disease, hip fracture, breast cancer, and stroke, a Markov decision analysis model was used to estimate the optimal strategy for maximizing survival for women at average risk of ovarian cancer. For each 5-year age group from 40 to 80 years, 4 strategies were compared: ovarian conservation or oophorectomy, and use of estrogen therapy or nonuse. Outcomes, as proportion of women alive at age 80 years, were measured. Sensitivity analyses were performed, varying both relative and absolute risk estimates across the range of reported values., Results: Ovarian conservation until age 65 benefits long-term survival for women undergoing hysterectomy for benign disease. Women with oophorectomy before age 55 have 8.58% excess mortality by age 80, and those with oophorectomy before age 59 have 3.92% excess mortality. There is sustained, but decreasing, benefit until the age of 75, when excess mortality for oophorectomy is less than 1%. These results were unchanged following multiple sensitivity analyses and were most sensitive to the risk of coronary heart disease., Conclusion: Ovarian conservation until at least age 65 benefits long-term survival for women at average risk of ovarian cancer when undergoing hysterectomy for benign disease.
- Published
- 2005
- Full Text
- View/download PDF
243. Total laparoscopic hysterectomy and laparoscopic supracervical hysterectomy.
- Author
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Parker WH
- Subjects
- Abdomen surgery, Cervix Uteri surgery, Female, Humans, Hysterectomy methods, Laparoscopy methods
- Abstract
Laparoscopic hysterectomy was first performed in 1989 and has become one of the procedures that may be offered to women with significant gynecologic symptoms. This article describes alternatives to hysterectomy, indications for laparoscopic hysterectomy, and outcomes and complications of laparoscopic hysterectomy as compared with vaginal and abdominal hysterectomy. Surgical technique for both total and supracervical hysterectomy are described as well as the learning curve, training, and credentialing for these procedures.
- Published
- 2004
- Full Text
- View/download PDF
244. Hysterectomy and sexual wellbeing: data were misrepresented.
- Author
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Parker WH
- Subjects
- Data Interpretation, Statistical, Female, Health Status, Humans, Hysterectomy psychology, Patient Satisfaction, Hysterectomy adverse effects, Sexual Dysfunction, Physiological etiology
- Published
- 2004
- Full Text
- View/download PDF
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