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Biomedical subjects

D F Martin

Publications and source records attributed to D F Martin.

At least 55 records · Page 3Linked to original sources

Causes, clinical features and non-operative management of bile leaks.

This paper evaluates the management of 31 patients with bile leaks identified over a 7-year period. Leaks complicated cholecystectomy in 19 patients (11 laparoscopic, 8 open), interventional procedures in 10 (including surgery in 1), trauma in one and was spontaneous in one case. Confirmation of the diagnosis typically lagged behind the onset of symptoms (mean for the group 4.2 days), indicating that a high index of suspicion is required in at-risk patients with typical symptoms. These include abdominal pain or distension, fever, bile leaking along a drain, jaundice, abnormal liver function tests and elevated white cell count. Two post-surgical bile leaks required surgical drainage of abdominal cellections. The remainder were successfully managed by non-operative methods including percutaneous drainage, endoscopic retrograde cholangiography with or without sphincterotomy or stent placement and percutaneous stenting. The spontaneous leak and all bile leaks complicating interventional procedures were managed non-operatively, although six patients in this group died due to the underlying malignant pathology. Only the patient with self-inflicted transection of the bile duct died directly from the complications of the bile leak. Although this is a varied, small series, we conclude that the majority of bile leaks can be managed by non-operative techniques. Whilst endoscopy is the primary modality for treatment, percutaneous techniques are crucially important for the management of complex cases and endoscopic failure.

Abdominal Pain↗

Uveal lymphoid infiltration. Report of four cases and clinicopathologic review.

PURPOSE: The purpose of the study was to report the clinicopathologic features of four patients with uveal lymphoid infiltration who were diagnosed by a conjunctival biopsy. DESIGN: A case series. PARTICIPANTS: Four patients at four institutions participated. MEASURES: The histopathologic findings of the conjunctival and episcleral biopsy specimens from four patients with the diagnosis of uveal lymphoid infiltration were recorded. The conjunctival specimens were placed in 10% neutral buffered formaldehyde solution or B5 solution and processed routinely for light microscopic examination and immunohistochemical analysis for B cells and T cells and kappa and lambda light chains. The clinical and histopathologic findings were compared with 47 previously reported cases of uveal lymphoid infiltration. RESULTS: Two men and two women (average age = 57 years) presented with diffuse punctate to coalescent yellow uveal infiltrates and epibulbar pink fleshy lesions. Ultrasonography of the lesions showed diffuse choroidal thickening and a lack of choroidal or scleral excavation. The conjunctival biopsy specimens showed diffuse infiltration of the substantia propria with B lymphocytes with variable kappa and lambda restriction. Scattered T lymphocytes also were present. Plasmacytoid cells and a prominent Grenz zone were present. CONCLUSIONS: Patients with solitary or multiple yellow uveal infiltrates should have careful conjunctival evaluation for the presence of pink conjunctival lesions. Biopsy specimens of the conjunctival lesion may establish the diagnosis of uveal lymphoid infiltration.

Adult↗

The safety sphincterotome: the device, the technique and preliminary results.

BACKGROUND AND STUDY AIMS: Endoscopic sphincterotomy is a widely used and safe procedure for the management of common bile duct stones, but little attention has been paid to the design of the sphincterotome and its influence upon risk of sphincterotomy. This study was undertaken to evaluate a sphincterotome, designed to incorporate known and original aspects which may contribute to safety. PATIENTS AND METHODS: 144 patients with bile duct stones were evaluated in an open prospective study of the use of the sphincterotome in performing endoscopic sphincterotomy. Evaluation included post-sphincterotomy complications, 30-day morbidity and mortality and effective duct clearance. RESULTS: Only one complication (0.7%) occurred in the group of 144 patients. Duct clearance of stones was ultimately achieved in 94%. CONCLUSIONS: Whilst more experience is necessary using the sphincterotome in the manner described, the absence of significant complications in all but one patient appears to support the philosophy behind the design of the sphincterotome.

Adult↗

Mutations in the cytomegalovirus UL97 gene associated with ganciclovir-resistant retinitis.

Vitreous from patients with cytomegalovirus (CMV) retinitis was studied in order to identify mutations in the CMV UL97 gene associated with clinical resistance to ganciclovir. Point mutations known to confer resistance (V460, I460, V594, and S595) were found in 6 of 11 study eyes. Rapid genetic screening by restriction enzyme analysis of viral DNA amplified directly from the vitreous was as effective as conventional sequencing in detecting these mutations. Repeat biopsy of 3 eyes revealed no change in the UL97 genotype. The UL97 genotype differed between eyes in 2 of 3 patients with bilateral, clinically resistant CMV retinitis. In summary, resistance mutations of the CMV UL97 gene are found in the vitreous of some, but not all, eyes with CMV retinitis that have not responded to ganciclovir therapy. These mutations can differ between eyes in patients with bilateral disease and can be rapidly detected using restriction digest analysis of polymerase chain reaction-amplified viral DNA.

AIDS-Related Opportunistic Infections↗

Glycoprotein B subtyping of cytomegalovirus (CMV) in the vitreous of patients with AIDS and CMV retinitis.

A 550-bp region of the cytomegalovirus (CMV) glycoprotein B (gB) gene was amplified by polymerase chain reaction (PCR) from 141 vitreous specimens of 120 patients with AIDS and CMV retinitis from three different metropolitan centers. The distribution of gB subtypes I, II, III, and IV were 19%, 43%, 12%, and 21%, respectively, based on restriction enzyme digestion patterns of PCR-amplified DNA. Two patients had simultaneous infection with two different gB subtypes. The ratio of gB subtypes was similar among the three geographically distinct patient populations. Two of 14 patients with bilateral vitreous specimens had different viral subtypes in each eye. In addition, different gB subtypes were observed in 1 of 6 patients with serial specimens. The ratio of different gB subtypes in the vitreous of patients with CMV retinitis is similar to that previously reported in the peripheral blood of patients with advanced AIDS.

Acquired Immunodeficiency Syndrome↗

Can bedside assessment reliably exclude aspiration following acute stroke?

OBJECTIVE: To investigate the ability of a bedside swallowing assessment to reliably exclude aspiration following acute stroke. SUBJECTS: Consecutive patients admitted within 24 h of stroke onset to two hospitals. METHODS: A prospective study. Where possible, all patients had their ability to swallow assessed on the day of admission by both a doctor and a speech and language therapist using a standardized proforma. A videofluoroscopy examination was conducted within 3 days of admission. RESULTS: 94 patients underwent videofluoroscopy; 20 (21%) were seen to be aspirating, although this was not detected at the bedside in 10. In 18 (22%) of the patients the speech and language therapist considered the swallow to be unsafe. In the medical assessment, 39 patients (41%) had an unsafe swallow. Bedside assessment by a speech and language therapist gave a sensitivity of 47%, a specificity of 86%, positive predictive value (PPV) of 50% and a negative predictive value (NPV) of 85% for the presence of aspiration. Multiple logistic regression was used to identify the optimum elements of the bedside assessments for predicting the presence of aspiration. A weak voluntary cough and any alteration in conscious level gave a sensitivity of 75%, specificity of 72%, PPV of 41% and NPV of 91% for aspiration. CONCLUSION: Bedside assessment of swallowing lacks the necessary sensitivity to be used as a screening instrument in acute stroke, but there are concerns about the use of videofluoroscopy as a gold standard. The relative importance of aspiration and bedside assessment in predicting complications and outcome needs to be studied.

Acute Disease↗

Diffuse anterior retinoblastoma.

PURPOSE: The authors describe the clinicopathologic features of an anterior variant of diffuse retinoblastoma. METHODS: The clinical history of a child with an anterior chamber infiltrate and cells in the anterior vitreous was reviewed. An anterior chamber aspirate was processed by a Millipore filter technique. The eye was enucleated and routinely processed for light and transmission electron microscopic examination. RESULTS: An 8-year-old girl was treated for anterior uveitis in her right eye that failed to resolve. Examination of an anterior chamber aspirate showed cells suggestive of retinoblastoma. The eye was enucleated, and the enucleation specimen showed retinoblastoma confined to the iris, ciliary body, and anterior vitreous with one microscopic focus of tumor in the peripheral retina. CONCLUSION: This variant of diffuse retinoblastoma involved only anterior ocular structures with minimal involvement of the retina.

Anterior Chamber↗

Macular hole surgery using thrombin-activated fibrinogen and selective removal of the internal limiting membrane.

PURPOSE: To evaluate a tissue sealant (autologous cryoprecipitate activated with bovine thrombin) as an adjuvant in macular hole surgery. METHODS: Sixty-nine patients with stage 2, 3, or 4 full-thickness macular hole were enrolled consecutively in a prospective pilot study. Anatomic closure of the macular holes with a single operation was the primary outcome. Fifty-eight patients had pre- and postoperative standardized measurements including best refracted visual acuity, reading speed, and contrast sensitivity. Group A patients (45) had primary macular holes; Group B patients (13) had recurrent macular holes or macular holes with "other" retinal pathology. Surgical technique was standardized and membrane dissections were optional. RESULTS: The anatomic closure rate was 80% with a minimum of 6 months follow-up. Mean improvement in visual acuity for Group A (2.9+/-0.4 lines) was significantly better than for Group B (0.8+/-0.5 lines; P = 0.008). Eyes that underwent internal limiting membrane (ILM) dissections had an anatomic closure rate of 96% (23/24), compared with 71% (32/45) in "non-ILM" cases (P = 0.034). Adverse reactions included sterile hypopyon (10%), intraretinal hemorrhage (9%), pigmentary hyperplasia (3%), and retinal detachment (3%). CONCLUSION: Tissue sealants should be evaluated as an adjuvant in macular hole surgery in a randomized clinical trial. Inflammatory reactions may occur in some patients. Internal limiting membrane dissection may improve anatomic closure rates without adversely affecting the visual acuity.

Adult↗

Treatment of cytomegalovirus retinitis with a sustained-release ganciclovir implant. The Ganciclovir Implant Study Group.

BACKGROUND: Sustained-release, intraocular implants that deliver ganciclovir are an alternative method for the treatment of cytomegalovirus retinitis in patients with the acquired immunodeficiency syndrome (AIDS). METHODS: We conducted a randomized study of 188 patients with AIDS and newly diagnosed cytomegalovirus retinitis. The patients were randomly assigned to treatment with an implant delivering 1 microg of ganciclovir per hour, an implant delivering 2 microg of ganciclovir per hour, or intravenous ganciclovir. The primary outcome we studied was progression of cytomegalovirus retinitis. RESULTS: The median time to progression of retinitis was 221 days with the 1-microg-per-hour implant (75 eyes), 191 days with the 2-microg-per-hour implant (71 eyes), and 71 days with ganciclovir administered intravenously (76 eyes; P<0.001). The risk of progression of retinitis was almost three times as great among patients treated with intravenous ganciclovir as among those treated with a ganciclovir implant (risk ratio, 2.8; P<0.001). However, the risk of disease in the initially uninvolved eye was lower with intravenous ganciclovir than with a ganciclovir implant (risk ratio, 0.5; P=0.19). Patients treated with intravenous ganciclovir were also less likely to have extraocular cytomegalovirus infections (0, vs. 10.3 percent in the two implant groups; P=0.04). CONCLUSIONS: For the treatment of cytomegalovirus retinitis, the sustained-release ganciclovir implant is more effective than intravenous ganciclovir, but patients treated with a ganciclovir implant alone remain at greater risk for the development of cytomegalovirus disease outside of the treated eye.

AIDS-Related Opportunistic Infections↗

Ganciclovir implant exchange. Timing, surgical procedure, and complications.

BACKGROUND: The ganciclovir implant is effective for the treatment of cytomegalovirus (CMV) retinitis. The device eventually runs out of drug, however, and must be replaced. We report our experience with exchanging ganciclovir implants during the course of a randomized clinical trial. METHODS: During our study, patients with newly diagnosed peripheral CMV retinitis were treated with a ganciclovir implant. The implant was scheduled for exchange at 32 weeks. It was exchanged earlier if progression of CMV retinitis occurred. Patient examinations and standard fundus photography were performed at 2-week intervals after the exchange procedure. RESULTS: Twenty-six exchange procedures were performed. Twenty-two eyes in 15 patients received a second implant and 4 eyes in 4 patients later received a third implant. Cytomegalovirus retinitis was rendered or maintained inactive in 22 of 23 cases with more than 1 month of follow-up after the second or third implants. Complications after the second implant procedure included transient vitreous hemorrhage in 5 eyes, postoperative inflammation in 1 eye, and retinal detachment in 1 eye. Median visual acuity returned to 20/25 by 28 days and to 20/20 by 42 days. Complications after the third implant procedure included dense vitreous hemorrhage in 3 of 4 eyes. Median survival time after a second implant procedure was 89 days. CONCLUSIONS: The initial ganciclovir implant exchange procedure is well tolerated with continued long-term control of CMV retinitis. Multiple reentries through the same wound may be associated with an increased risk for vitreous hemorrhage.

Antiviral Agents↗

A pilot exploratory study of oral electrical stimulation on swallow function following stroke: an innovative technique.

This pilot study investigated the effect of oral electrical stimulation on swallow function in stroke patients with chronic dysphagia. The purpose was to determine whether an innovative technique could make an improvement in swallow function that might be developed as a potential treatment for patients with persistent dysphagia. Four stroke patients with chronic dysphagia were recruited on the basis of videofluoroscopic findings of a delayed swallow reflex. A single case design was used. Oral electrical stimulation of swallowing was carried out using a palatal prosthesis starting at an output pulse of 0.5 mA, with a fixed duration of 200 microsec, repeated at 1-sec intervals. Barium paste (1 x 5 ml) was introduced at the level of the patient's maximum tolerance of stimulation and any effect on swallow function was recorded by videofluoroscopy. The findings from the pilot study indicated that oral electrical stimulation resulted in an improvement in swallow function in 2 of the 4 patients. The stimulation was well tolerated in all cases with no serious adverse effects. These early results are promising, but further research is needed.

Aged↗

The natural history of dysphagia following a stroke.

To assess the frequency and natural history of swallowing problems following an acute stroke, 121 consecutive patients admitted within 24 hours of the onset of their stroke were studied prospectively. The ability to swallow was assessed repeatedly by a physician, a speech and language therapist, and by videofluoroscopy. Clinically 51% (61/121) of patients were assessed as being at risk of aspiration on admission. Many swallowing problems resolved over the first 7 days, through 28/110 (27%) were still considered at risk by the physician. Over a 6-month period, most problems had resolved, but some patients had persistent difficulties (6, 8%), and a few (2, 3% at 6 months) had developed swallowing problems. Ninety-five patients underwent videofluoroscopic examination within a median time of 2 days; 21 (22%) were aspirating. At 1 month a repeat examination showed that 12 (15%) were aspirating. Only 4 of these were persistent; the remaining 8 had not been previously identified. This study has confirmed that swallowing problems following acute stroke are common, and it has been documented that the dysphagia may persist, recur in some patients, or develop in others later in the history of their stroke.

Aged↗

A polymerase chain reaction-based assay for diagnosing varicella-zoster virus retinitis in patients with acquired immunodeficiency syndrome.

PURPOSE: To develop a rapid, sensitive, and specific laboratory assay based on the polymerase chain reaction for the diagnosis of varicella-zoster virus retinitis in patients with acquired immunodeficiency syndrome (AIDS). METHODS: We developed and tested a polymerase chain reaction-based assay for the detection of varicella-zoster virus DNA in vitreous samples. We attempted to detect varicella-zoster virus DNA in 14 vitreous samples from patients with AIDS and a clinical diagnosis of progressive outer retinal necrosis syndrome. For controls, we also attempted to detect varicella-zoster virus DNA in vitreous samples from 75 immunocompetent patients with vitreoretinal disease and 88 patients with AIDS and vitreoretinal inflammatory disease not related to progressive outer retinal necrosis syndrome. RESULTS: Varicella-zoster virus DNA was detected in 11 of 14 vitreous samples from AIDS patients with progressive outer retinal necrosis syndrome. All three samples that scored negative for varicella-zoster virus DNA came from eyes that had been treated aggressively with antiviral drugs and had clinically inactive disease at the time of vitreous biopsy. Varicella-zoster virus DNA was detected in only two of 75 control vitreous samples from immunocompetent patients with vitreoretinal disease and two of 88 control vitreous samples from patients with AIDS and vitreoretinal inflammatory disease not related to progressive outer retinal necrosis syndrome. CONCLUSION: We have developed a rapid, sensitive, and specific polymerase chain reaction-based diagnostic assay for varicella-zoster virus DNA that will assist in the diagnosis of varicella-zoster virus retinitis in patients with AIDS.

Acquired Immunodeficiency Syndrome↗

Misplacement of endoscopic biliary endoprostheses.

Four patients with cholangiocarcinoma involving the common hepatic duct or the confluence of the hepatic ducts are described here, in whom endoscopically placed endoprostheses were unknowingly misplaced, with their proximal portions lying outside the bile duct system. Because of persisting jaundice, the stents were changed endoscopically in three cases on several occasions, but the misplacement was not recognized. The problem was recognized during percutaneous transhepatic cholangiography in all four patients, with percutaneous stent placement allowing resolution of the jaundice. The avoidance and management of this complication is discussed.

Aged↗

Endoscopic management of Mirizzi's syndrome.

BACKGROUND: The accepted management of Mirizzi's syndrome is surgical, but endoscopic and percutaneous management have been described. AIM: To review our experience of endoscopic intervention for Mirizzi's syndrome. PATIENTS AND METHODS: ERCP reports of patients presenting for endoscopic management of choledocholithiasis between March 1989 and June 1995 were reviewed. Those with cholangiographic evidence of Mirizzi's syndrome were selected for study. Patient records and cholangiograms were reviewed and follow up was recorded from the notes or by telephone contact with patients, their relatives, or doctors. RESULTS: Twenty five patients had Mirizzi's syndrome. Sixteen were female and their median age was 67 years (range 28-91). Ten presented with painless jaundice, nine with painful jaundice, four with cholangitis, and two had pain as their only symptom. Twelve were referred for surgery and 11 of these had preliminary endoscopic therapy. Thirteen have been treated solely with endoscopic therapy. Treatment in this group was aimed at relieving jaundice and removing stones. Stones were completely removed in three patients. Nine patients have been treated with long term stents, and one awaits extracorporeal shockwave lithotripsy of the gall bladder. Complications of treatment occurred in four of 25 after ERCP. CONCLUSIONS: Endoscopic treatment of Mirizzi's syndrome is effective as a temporising measure before surgery and can be definitive treatment for unsuitable surgical candidates.

Adult↗

Are complications of endoscopic sphincterotomy age related?

BACKGROUND: Endoscopic retrograde cholangiopancreatography sphincterotomy is increasingly performed in younger patients undergoing laparoscopic cholecystectomy. However, the safety of endoscopic sphincterotomy in this age group, relative to that in older patients, is unknown. AIM: To determine whether the development of short term complications following endoscopic sphincterotomy is age related. PATIENTS AND METHODS: A prospective multicentre audit of 958 patients (mean age 73, range 14-97, years) undergoing a total of 1000 endoscopic sphincterotomies. RESULTS: Two deaths occurred, both from postsphincterotomy acute pancreatitis. Postprocedural complications developed in 24 patients: pancreatitis in 10, ascending cholangitis in seven, bleeding in four, and retroperitoneal perforation in three. There were six complications (five cases of pancreatitis and one bleed; 2.2%) and no deaths in the 281 (29.3%) patients aged under 65 years. In comparison, 18 (2.6%) of the 677 patients aged over 65 years developed a complication (cholangitis in seven, pancreatitis in five, bleeding in three, and perforation in three). Patients under 35, 45, 55, and 65 years were not at significantly increased risk of complication than those over these ages (relative risk for those under compared with those over 65 years 0.83, 95% confidence intervals 0.41-1.67, p = 0.74). CONCLUSION: Short term complications following endoscopic sphincterotomy are not related to age. Younger patients undergoing laparoscopic cholecystectomy need not be denied endoscopic sphincterotomy for fear that the risks are greater than if they undergo surgical exploration of the common bile duct.

Adolescent↗