Search PubMed⌕ Search

Biomedical subjects

C Sutton

Publications and source records attributed to C Sutton.

At least 37 records · Page 2Linked to original sources
PubMed1998

Validation of virtual reality to teach and assess psychomotor skills in laparoscopic surgery: results from randomised controlled studies using the MIST VR laparoscopic simulator.

Objective assessment of surgical technique is currently impossible. A virtual reality simulator for laparoscopic surgery (MIST VR) models the movements needed to perform minimally invasive surgery and can generate a score for various aspects of psychomotor skill. Two studies were performed using the simulator: first to assess surgeons of different surgical experience to validate the scoring system; second to assess in a randomised controlled way, the effect of a standard laparoscopic surgery training course. Experienced surgeons (> 100 laparoscopic cholecystectomies) were significantly more efficient, made less correctional submovements and completed the virtual reality tasks faster than trainee surgeons or non-surgeons. The training course caused an improvement in efficiency and a reduction in errors, without a significant increase in speed when compared with the control group. The MIST VR simulator can objectively assess a number of desirable qualities in laparoscopic surgery, and can distinguish between experienced and novice surgeons. We have also quantified the beneficial effect of a structured training course on psychomotor skill acquisition.

Cholecystectomy↗
PubMed1997

Hysterectomy: a historical perspective.

In the relatively long history of man, surgery has been a comparatively recent development; the abdomen was first deliberately opened to remove an ovarian cyst by Ephraim McDowell in Kentucky in 1809. The first abdominal hysterectomy was performed by Charles Clay in Manchester, England in 1843; unfortunately the diagnosis was wrong and the patient died in the immediate post-operative period. The following year, Charles Clay was almost the first to claim a surviving patient, however she died post-operatively and it was not until 1853 that Ellis Burnham from Lowell, Massachusetts achieved the first successful abdominal hysterectomy although again the diagnosis was wrong. Vaginal hysterectomy dates back to ancient times. The procedure was performed by Soranus of Ephesus 120 years after the birth of Christ, and the many reports of its use in the middle ages were nearly always for the extirpation of an inverted uterus and the patients rarely survived. The early hysterectomies were fraught with hazard and the patients usually died of haemorrhage, peritonitis, and exhaustion. Early procedures were performed without anaesthesia with a mortality of about 70%, mainly due to sepsis from leaving a long ligature to encourage the drainage of pus. Thomas Keith from Scotland realized the danger of this practice and merely cauterized the cervical stump and allowed it to fall internally, thereby bringing the mortality down to about 8%. Hysterectomy became safer with the introduction of anaesthesia, antibiotics and antisepsis, blood transfusions and intravenous therapy. During the 1930s, Richardson introduced the total abdominal hysterectomy to avoid serosanguineous discharge from the cervical remnant and the risk of cervical carcinoma developing in the stump. Apart from this innovation, and the transverse incision introduced by Johanns Pfannenstiel in the 1920s, there was little advance in hysterectomy techniques until the advent of endoscopic surgery and the performance of the first laparoscopic hysterectomy by Harry Reich in Kingston, Pennsylvania in 1988. The refinement and increasing safety of laparoscopic hysterectomy suggests that it will be used increasingly in the future, although developments in pharmacology and photodynamic therapy and interventional radiology may reduce the traditional indications for the operation.

Anesthesia, General↗
PubMed1997

The fate of the 'modern' artificial urinary sphincter with a follow-up of more than 10 years.

OBJECTIVE: To assess the long-term outcome of patients who had an artificial urinary sphincter (AUS) implanted between 10 and 15 years ago. PATIENTS AND METHODS: Of 68 patients who had an AUS implanted more than 10 years ago, 61 were followed with sufficient detail for analysis. Thirty-four had a neuropathic bladder with sphincter dysfunction, 15 had post-prostatectomy sphincter weakness incontinence and 12 further patients had a variety of indications. RESULTS: The 61 patients experienced a total of 58 major complications and 49 have required at least one revision procedure. Currently eight (13%) patients are satisfactorily continent with their original AUS in situ and 29 others have a satisfactory revised AUS. Thus 37 of 61 (61%) are continent using an AUS at least 10 years after first implantation. Eleven patients died and of these two had a satisfactory original AUS in situ and seven had successful revisions. In two patients the AUS failed but they were considered unfit for revision. Four female patients were continent and used intermittent catheterization after the explantation of eroded AUS cuffs. In seven patients the AUS was abandoned; two of these patients reverted to condom drainage and five had continent or incontinent urinary diversions fashioned. Thus, if those who died with a functioning AUS are included, 46 of 61 (75%) achieved long-term continence with the AUS. CONCLUSIONS: Despite the high complication and revision rate, these results show that acceptable continence rates can be achieved in the long-term, particularly in the male neuropathic bladder and in those with post-prostatectomy sphincter weakness. Many of the complications encountered may be less common with the current re-designed models of the AUS. However, it is essential that both surgeon and patient recognize and accept the likelihood of complications and revisions before using the AUS. The continued use of the AUS where simpler methods of obtaining continence are inappropriate remains justified.

Adolescent↗
PubMed1997

MIST VR. A laparoscopic surgery procedures trainer and evaluator.

The key bimanual instrument tasks involved in laparoscopic surgery have been abstracted for use in a virtual reality surgical skills evaluator and trainer. The trainer uses two laparoscopic instruments mounted on a frame with position sensors which provide instrument movement data that is translated into interactive real time graphics on a PC (P133, 16 Mb RAM, graphics acceleration card). An accurately scaled operating volume of 10 cm3 is represented by a 3D cube on the computer screen. "Camera" position and size of target objects can be varied for different skill levels. Targets appear randomly within the operating volume according to the skill task and can be grasped and manipulated with the instruments. Accuracy and errors during the tasks and time to completion are logged. Mist VR has tutorial, training, examination, analysis and configuration modes. Six tasks have been selected and include combinations of instrument approach, target acquisition, target manipulation and placement, transfer between instruments, target contact with optional diathermy, and controlled instrument withdrawal/replacement. Tasks can be configured for varying degrees of difficulty and the configurations saved to a library for reuse. Specific task configurations can be assigned to individual students. In the examination mode the supervisor can select the tasks, repetitions and order and save to a specific file for that trainee. Progress can be assessed and there is the option for playback of the training session or examination. Data analyses permit overall, including task, and right or left hand performances to be quantified. Mist VR represents a significant advance over the subjective assessment of training performances with existing "plastic box" basic trainers.

Computer-Assisted Instruction↗
PubMed1996

Endometrial ablation using a distensible multielectrode balloon.

The VestaBlate system uses a multielectrode intrauterine balloon as a device to create effective and safe endometrial ablation (EA). The surface of the distensible balloon is impregnated with thermistors and thin, platelike electrodes. It is designed to deliver low-power electroenergy to the endometrium. Unlike the resectoscope techniques that require nonelectrolytic fluids for uterine distention, moving electrodes at high power outputs, and other variables that are operator dependent, the VestaBlate is computer controlled using a standard type electrosurgical generator. A respiratory enzyme stain, nitroblue tetrazoleum, was used to determine the extent and depth of tissue necrosis to a myometrial depth of 2 to 4 mm with uniform destruction of tissue with power setting at 45 W for a 4-minute application of energy. Sixty-nine patients have been treated, with 45 followed for at least 3 to 9 months. The amenorrhea rate is 40%; the oligomenorhea-hypomenorrhea rate is 49%.

Electrodes↗
PubMed1996

Engineering of DNA binding proteins into site-specific cutters: reactivity of Trp repressor-1,10-phenanthroline chimeras.

Trp repressor (TrpR) can be converted into a site-specific nuclease by chemical modification of the cysteine mutants TrpR D46C or TrpR E49C with 5-iodoacetamido-1,10-phenanthroline (OP). In the presence of cupric ion and 3-mercaptopropionic acid, TrpR-regulated operators are cleaved. The properties of these semisynthetic scission reagents have been compared. The E49C construct cleaves efficiently at two sites within the operator and the D46C cleaves at multiple sites. Molecular modeling indicates that the reason for the focused reactivity of E49C is that the OP is rigidly oriented in the protein-DNA complexes whereas the OP can adopt several orientations in TrpR D46C. Mutations and reaction conditions that increase the affinity of the repressor enhance the scission efficiency which approaches 100% within the acrylamide matrix. TrpR E49C-OP smoothly cleaves the trpEDCBA operator in a plasmid in a reaction dependent on the corepressor L-tryptophan. In the absence of tryptophan, non-specific cleavage of the plasmid is observed under the same conditions. Therefore, tryptophan not only directs cleavage to a specific site but also blocks it at non-specific sites. The analysis of the cleavage pattern of the trpEDCBA operator provides strong evidence for the tandem binding model in which protein-protein interactions stabilize binding on the DNA. TrpR E49C-OP should serve as the basis for the engineering of a family of highly specific semisynthetic scission reagents.

Bacterial Proteins↗
PubMed1996

Production of anti-erythrocyte antibodies by leukemic and nonleukemic B cells in chronic lymphocytic leukemia patients.

We have assessed the specificity of antibodies from the leukemic B cells of five patients with both chronic lymphocytic leukemia and autoimmune hemolytic anemia (CLL-AHA). Leukemic cells from one patient displayed surface immunoglobulin with heavy and light chain isotypes identical to that of the patient's anti-red blood cell (RBC) antibodies, and the leukemic cells secreted antibodies in vitro with anti-RBC activity. However, in the remaining patients, the leukemic cells displayed surface immunoglobulin with light chain isotypes different from that of the patient's anti-RBC antibodies and secreted antibodies in vitro with no detectable anti-RBC activity. Thus, there are two distinct classes of CLL-AHA patients, differentiated by the presence or absence of an anti-RBC antibody-producing leukemic B cell clone. The apparent heterogeneity in the source of pathogenic anti-RBC antibodies may impact the treatment response of the two classes of CLL-AHA patients.

Aged↗
PubMed1995

Power sources in endoscopic surgery.

The power sources used in endoscopic surgery are varied and numerous, and will continue to improve as technology progresses. Early attempts at operative laparoscopy were crude, limited by the available instrumentation, and tended to be frustrating: scissors that had to be frequently sharpened and endocoagulators that took a seemingly interminable time to achieve their tissue effect. New developements in ultrasonic energy and different wavelengths of laser energy are used alongside increasingly sophisticated electrosurgical tools, employing both monopolar and bipolar systems, and innovative delivery systems such as the argon beam coagulator and the Helica Thermal Coagulator. All of these systems have their advocates and their detractors, but in the end the choice of power source is determined by the type of equipment that the operator feels most comfortable with. The surgeon must have a detailed knowledge of the physical concepts required to generate the power source, and be able to understand the complications that can be created by the energy, how to avoid them, how and to deal with them if they occur. Although there are subtle differences in the reaction of the different energy sources with human tissue, the clinical outcome appears to be much the same, and depends more on the skill of the individual surgeon than the power source employed.

Electric Power Supplies↗
PubMed1994

Primary central nervous system lymphoma. Results at the University of California at Los Angeles and review of the literature.

The authors report 24 patients with primary central nervous system lymphoma (PCNSL) treated from 1977 to 1992. There were 13 females and 11 males. Median age was 57 (range: 17-84). Patients were symptomatic for a median of 3 months. Headache was the most common complaint. Median Karnofsky performance score was 70. There were 19 patients with solitary PCNSL, and 5 had multiple deposits. Disease was confined to the supratentorium in 23 patients. Cerebrospinal fluid cytology was positive in 5 of 22 patients examined. All patients received whole-brain irradiation with or without supplemental tumor boost. Tumor doses ranged from 10 to 60 Gy. Intrathecal chemotherapy was administered to 16 patients and 7 received systemic agents. After follow-up ranging from 1 to 66 months, median survival and progression-free survival were each 8 months. One- and 3-year actuarial survival rates were 50% and 36%, respectively. One- and 3-year actuarial progression-free rates were 41% and 15%, respectively. Relapse occurred in 18 patients, and in 17 there was a component of local progression. Lesions recurred in the spinal meninges in 1 patients and in the vitreous in 1. Patients with Karnofsky performance status > or = 70 demonstrated median progression-free survival of 27 months, compared to 4 months for patients < 70 (p = .024). No other significant patient or treatment-related prognostic factors were identified. Clinical dementia occurred in 2 of 11 patients surviving at least 1 year. Review of the literature indicates PCNSL demonstrates relative radioresistance. The most immediate improvement in prognosis for patients with PCNSL can be achieved by properly sequencing systemic and intrathecal chemotherapy with radiation therapy.

Actuarial Analysis↗
PubMed1993

Effects of stent design and serum cholesterol level on the restenosis rate in atherosclerotic rabbits.

We investigated the effect of serum cholesterol level and stent design on the restenosis rate within the stent after balloon angioplasty and stent implantation using atherosclerotic rabbits. Two types of nickel/titanium stents with gaps (open stent) and without gaps (closed stent) between the wire coils were implanted into the aorta of the rabbits 10 weeks after atherosclerosis had been induced using a standard high cholesterol diet and balloon abrasion. Each rabbit had an open stent and a closed stent implanted into the infrarenal abdominal aorta. Between these two stents a control segment of the aorta was treated with angioplasty alone. The animals were divided into two groups according to the diet protocol as follows: in group I (n = 9) a high cholesterol diet was stopped after stent implantation; in group II (n = 10) a high cholesterol diet was maintained after stent implantation. Digital subtraction angiograms were obtained every 4 weeks for up to 24 weeks and the narrowest diameter of the arterial segments within each stent and in the segment between stents was measured. The diameter narrowing within the closed stent was greater in the high cholesterol group compared with the low cholesterol group: 12 weeks (2.57 +/- 0.09 mm in group I vs 2.14 +/- 0.15 mm in group II, mean +/- S.E., p < 0.05); 16 weeks (2.55 +/- 0.09 mm vs 2.14 +/- 0.12 mm, p < 0.05); 20 weeks (2.59 +/- 0.06 mm vs 1.98 +/- 0.12 mm, p < 0.01); and 24 weeks (2.45 +/- 0.11 mm vs 2.01 +/- 0.11 mm, p < 0.05). No significant differences in the narrowest diameter of the arterial segments were observed between high and low cholesterol groups in the angioplasty alone areas or within the open stents. There was a significant difference in the narrowest diameter between stents with versus those without gaps (at 12, 16, and 20 weeks poststenting in group I and at 4, 8, 12, 16, 20, and 24 weeks in group II). Thus the stent with the least metal is correlated with less stenosis and intimal hyperplasia. From these data we conclude that both stent design and serum cholesterol are important factors for restenosis after stent implantation.

Angioplasty, Balloon, Coronary↗
PubMed1993

A psychological profile of endometriosis patients in comparison to patients with pelvic pain of other origins.

In order to investigate the possibility of a specific psychological profile associated with endometriosis, 81 women with pelvic pain were studied, of whom 40 were diagnosed as having endometriosis and 41 other gynaecological problems. Each patient completed six standardized psychometric tests to assess personality, psychopathology, marital state and pain. Endometriosis patients obtained higher psychoticism, introversion and anxiety scores in comparison to the other pain patients, although the two groups did not differ on pain ratings. Both groups obtained neuroticism, anxiety and psychiatric morbidity scores which were elevated relative to normative data. The possibility that there are certain psychological characteristics which make some women vulnerable to endometriosis is discussed.

Adult↗
PubMed1993

Lasers in infertility.

Lasers have been used in fertility surgery for the past two decades. This article reviews the development of different wavelength lasers, the different tissue effects and their applications in infertility surgery. The CO2 laser remains the most precise laser, especially in the ultrapulse mode, for the division of adhesions and the accurate and safe vaporization of deposits of endometriosis. The neodymium:YAG laser, because of its greater depth of penetration, is more suited to hysteroscopic surgery, and attempts to focus the energy by sapphire tips and sculpted quartz fibres merely enable tissue to be incised by a thermal effect. Carbon dioxide laser energy is strongly absorbed by the water molecule and is rendered ineffective in the presence of blood so the visible light lasers, argon and potassium titanyl phosphate (KTP/532) lasers, are more suitable for the treatment of ovarian endometriomas and ectopic pregnancies. Techniques and results of laser surgery in endometriosis, tubal surgery, ectopic pregnancy and polycystic ovarian syndrome are reviewed. The main advantage of the various lasers is that they allow fertility surgeons to perform operative surgery by the minimally invasive approach of laparoscopy rather than laparotomy.

Endometriosis↗