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D R Larson

Publications and source records attributed to D R Larson.

26 records · Page 2Linked to original sources
PubMed1998

Chromosomal abnormalities in systemic amyloidosis.

Primary systemic amyloidosis (AL) is a plasma cell disorder characterized by deposition of monoclonal light chains in different organ systems. Although multiple and complex numerical chromosomal abnormalities have been described in patients with multiple myeloma, it is currently unknown whether such changes occur in systemic amyloidosis. Bone marrow samples from 21 patients with AL were studied by standard cytogenetics and interphase fluorescence in situ hybridization (FISH) for the presence of numerical chromosomal abnormalities. We tested for six chromosomes (7, 11, 9, 15, 18 and X) using centromere-specific probes. The monoclonal plasma cells were identified by simultaneous fluorescent staining of the monotypic cytoplasmic immunoglobulin. We compared these results with those obtained from 19 patients with monoclonal gammopathy of undetermined significance (MGUS) and normal controls. Multiple numerical chromosomal abnormalities were detected in AL by interphase FISH, including trisomy of chromosomes 7 (42%), 9 (52%), 11 (47%), 15 (39%), 18 (33%) and X (13% in women and 54% in men). Monosomy of chromosome 18 was seen in 72% of cases. Previous exposure to alkylator therapy did not appear to correlate with these abnormalities. No significant difference was observed in the prevalence of these abnormalities between AL and MGUS. Multiple chromosomal numerical abnormalities were detected by interphase FISH analysis in patients with AL, especially monosomy of chromosome 18. Aneuploidy in the monotypic plasma supports a neoplastic nature for the disorder.

Adult↗
PubMed1997

Long-term results after reoperation for failed antireflux procedures.

From January 1960 to June 1995, 185 patients underwent reoperation without esophageal resection for symptoms of recurrent gastroesophageal reflux disease. There were 102 men and 83 women. Median age was 58 years (range 20 to 84 years). A single previous antireflux operation had been performed in 147 patients, two in 33, and three in 5. The median interval between the reoperation and the previous operation was 36 months (range 1 to 291 months). Indications for reoperation were symptoms in 184 patients and a large paraesophageal hernia in one patients. The surgical approach was by means of a thoracotomy in 133 patients (71.9%), laparotomy in 27 (14.6%), and a thoracoabdominal incision in 25 (13.5%). A Nissen fundoplication was performed in 107 patients (57.8%), Belsey fundoplication in 47 (25.4%), truncal vagotomy and antrectomy with Roux-en-Y reconstruction in 17 (9.2%), anatomic hernia repair in 12 (6.5%), and Hill gastropexy in 2 (1.1%). A Collis gastroplasty was added to the fundoplication in 116 patients (62.7%), and a pyloroplasty was performed in 17 (9.2%). There was one operative death (0.5%). Complications occurred in 47 patients (25.4%). Median postoperative hospitalization was 9 days (range 5 to 58 days). Follow-up was complete in 156 patients (84.3%) and ranged from 3 to 283 months (median 44 months). Improvement occurred in 137 patients (87.8%). Functional results were classified as excellent in 65 patients (41.6%), good in 29 (18.6%), fair in 43 (27.6%), and poor in 19 (12.2%). No single operative approach or procedure proved to be functionally superior. We conclude that reoperation with esophageal preservation after a failed antireflux procedure will result in significant functional benefit and can be performed with low mortality and acceptable morbidity. The type of repair should be tailored to the individual patient.

Adult↗
PubMed1997

Management of colonoscopic perforations.

OBJECTIVE: To document our evolving surgical management of colonoscopic perforation and examine factors crucial to the improvement of patient care. DESIGN: We conducted a computer-based retrospective analysis of medical records (1980 through 1995). MATERIAL AND METHODS: Among 57,028 colonoscopic procedures performed, 43 patients (0.075%, or 1 perforation in 1,333 procedures) had a colonic perforation. Two additional patients were treated after colonoscopy performed elsewhere. The outcomes analyzed included surgical morbidity and mortality. RESULTS: Twenty-six women and 19 men who ranged in age from 28 to 85 years (median, 69) were treated for colonic perforation. More than 80% of perforations occurred during the latter half of the study period because of the increased volume of colonoscopic procedures (8 perforations among 12,581 examinations from 1980 through 1987 versus 35 perforations among 44,447 colonoscopies from 1988 through 1995). Emergency laparotomy was performed in 42 patients (93%). Perforations occurred throughout the colon: right side = 10; transverse = 9; and left side = 23. Three patients without evidence of peritoneal irritation fared well with nonoperative management. Most patients underwent primary repair or limited resection in conjunction with end-to-end anastomosis. In 14 patients (33%), an ostomy was created. One patient underwent laparotomy without further treatment. Intra-abdominal contamination ranged from none (31%) to local soiling (48%) to diffusely feculent (21%). Postoperative complications occurred in 12 patients and were associated with older age (P = 0.01), large perforations (P = 0.03), and prior hospitalization (P = 0.04). No postoperative deaths occurred. CONCLUSION: Despite a consistently low risk of colonic perforation, the increasing use of colonoscopy in our practice has resulted in an increased number of iatrogenic colonic perforations. In order to minimize morbidity and mortality, prompt operative intervention is the best strategy in most patients. Non-operative management is warranted in carefully selected patients without peritoneal irritation.

Adult↗
PubMed1997

Echocardiographic assessment of commissural calcium: a simple predictor of outcome after percutaneous mitral balloon valvotomy.

OBJECTIVES: This study was undertaken to determine whether the presence of calcium in the mitral valve commissures, as demonstrated echocardiographically, could predict outcome and to compare this with an established echocardiographic scoring system. BACKGROUND: Percutaneous mitral balloon valvotomy is an effective form of treatment for mitral valve stenosis. It is important to identify patients who would benefit from this procedure. Commissural splitting is the dominant mechanism by which mitral valve stenosis is relieved by this technique, and thus commissural morphology may predict outcome. METHODS: One hundred forty-nine consecutive patients who underwent percutaneous mitral balloon valvotomy at the Mayo Clinic were evaluated retrospectively. The morphology of the mitral valve apparatus on the baseline echocardiograms was scored in blinded manner using a semiquantitative grading system of leaflet thickening, mobility, calcification and subvalvular thickening (Abascal score). Additionally, each of the medial and lateral commissures was graded for the presence or absence of calcification. End points were death, New York Heart Association functional class, repeat percutaneous mitral balloon valvotomy and mitral valve replacement at follow-up. RESULTS: The mean follow-up period was 1.8 years (maximum 7.9 years). Univariate predictors of death and all events combined included age, the use of a double-balloon technique, the presence of calcium in a commissure and the Abascal score, as continuous variables. Patients with an Abascal score < or = 8 showed a trend toward improved survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (78 +/- 6% vs. 67 +/- 8%, p = 0.07) and free of all events combined (75 +/- 6% vs. 64 +/- 8%, p = 0.07) versus those patients with a score > 8. However, survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (86 +/- 4% vs. 40 +/- 4%) and free of all events combined (82 +/- 5% vs. 38 +/- 10%) at follow-up was significantly different between patients without commissural calcium and those with commissural calcium (p < 0.001). In a Cox regression model with Abascal score and commissural calcium and their interaction, calcification emerged as the only significant variable (p < 0.01). CONCLUSIONS: The presence of commissural calcium is a strong predictor of outcome after percutaneous mitral balloon valvotomy. Patients with evidence of calcium in a commissure have a lower survival rate and a higher incidence of mitral valve replacement and all end points combined. Thus, the simple presence or absence of commissural calcification assessed by two-dimensional echocardiography can be used to predict outcome.

Calcinosis↗
PubMed1997

Dual-chamber pacing for hypertrophic cardiomyopathy: a randomized, double-blind, crossover trial.

OBJECTIVES: In a double-blind, randomized, crossover trial we sought to evaluate the effect of dual-chamber pacing in patients with severe symptoms of hypertrophic obstructive cardiomyopathy. BACKGROUND: Recently, several cohort trials showed that implantation of a dual-chamber pacemaker in patients with severely symptomatic hypertrophic obstructive cardiomyopathy can relieve symptoms and decrease the severity of the left ventricular outflow tract gradient. However, the outcome of dual-chamber pacing has not been compared with that of standard therapy in a randomized, double-blind trial. METHODS: Twenty-one patients with severely symptomatic hypertrophic obstructive cardiomyopathy were entered into this trial after baseline studies consisting of Minnesota quality-of-life assessment, two-dimensional and Doppler echocardiography and cardiopulmonary exercise tests. Nineteen patients completed the protocol and underwent double-blind randomization to either DDD pacing for 3 months followed by backup AAI pacing for 3 months, or the same study arms in reverse order. RESULTS: Left ventricular outflow tract gradient decreased significantly to 55 +/- 38 mm Hg after DDD pacing compared with the baseline gradient of 76 +/- 61 mm Hg (p < 0.05) and the gradient of 83 +/- 59 mm Hg after AAI pacing (p < 0.05). Quality-of-life score and exercise duration were significantly improved from the baseline state after the DDD arm but were not significantly different between the DDD arm and the backup AAI arm. Peak oxygen consumption did not significantly differ among the three periods. Overall, 63% of patients had symptomatic improvement during the DDD arm, but 42% also had symptomatic improvement during the AAI backup arm. In addition, 31% had no change and 5% had deterioration of symptoms during the DDD pacing arm. CONCLUSIONS: Dual-chamber pacing may relieve symptoms and decrease gradient in patients with hypertrophic obstructive cardiomyopathy. In some patients, however, symptoms do not change or even become worse with dual-chamber pacing. Subjective symptomatic improvement can also occur from implantation of the pacemaker without its hemodynamic benefit, suggesting the role of a placebo effect. Long-term follow-up of a large number of patients in randomized trials is necessary before dual-chamber pacing can be recommended for all patients with severely symptomatic hypertrophic obstructive cardiomyopathy.

Adult↗
PubMed1997

Acute pseudo-obstruction of the colon as a postoperative complication of hip arthroplasty.

Acute pseudo-obstruction of the colon (Ogilvie syndrome) results in massive colonic dilatation that may lead to a life-threatening perforation. This complication is known to occur after arthroplasty of the hip, yet the prevalence of the complication and its effects on the outcome of the procedure are unknown. We reviewed the records of thirty patients (mean age, 74.3 years; range, fifty-six to ninety years) in whom acute colonic pseudo-obstruction developed after hip arthroplasty between 1984 and 1993. During this ten-year period, 10,468 hip arthroplasties were performed at our institution; therefore, the prevalence of acute colonic pseudo-obstruction was 0.29 per cent. The most common presenting symptom was abdominal distention, which occurred a mean of 3.5 days (range, one to eleven days) postoperatively and was noted in twenty-seven of thirty patients. Nausea (fourteen patients), vomiting (eight patients), and abdominal pain (two patients) were observed less frequently. Twenty-one associated medical complications, including pulmonary embolism (four patients), upper gastrointestinal bleeding (three patients), and deep infection (not evident intraoperatively) at the site of the arthroplasty (two patients), developed in fifteen patients. Eighteen of the twenty-one complications occurred after the onset of colonic pseudo-obstruction. The associated medical problems resulted in four deaths (13 per cent). Recognition by the orthopaedic surgeon of the presenting features of acute colonic pseudo-obstruction is important in order to facilitate prompt initiation of treatment, which may hasten recovery and reduce the morbidity and the mortality associated with this complication.

Abdomen↗
PubMedDate not supplied

Outcome of patients undergoing ileal pouch-anal anastomosis for left-sided chronic ulcerative colitis.

Chronic ulcerative colitis is not a uniform disease entity because the clinical pattern and disease characteristics differ on the basis of the anatomic location of the inflammation. The aim of this study was to compare the preoperative characteristics, postoperative complications, and long-term functional outcome of ileal pouch-anal anastomosis (IPAA) in patients with left-sided colitis to those same characteristics in patients with pancolitis. Between 1990 and 1996, a total of 565 patients underwent IPAA for chronic ulcerative colitis at our institution. Of these, 111 patients were determined to have left-sided involvement, whereas 283 patients had pancolitis. The mean age at surgery was greater in the patients with left-sided colitis (37 years vs. 34 years, P = 0.01), and the mean duration of disease (8.7 years vs. 7.7 years, P = 0.05) tended toward a significant difference between the left-sided colitis and pancolitis groups. The complication rates were similar with the exception of small bowel obstructions, for which there was a higher incidence in the group with left-sided colitis (27% vs. 13%, P = 0.002) at 5 years. The incidence of pouchitis (43% vs. 39%) at 5 years was comparable. Long-term functional results and quality-of-life assessment did not show any significant differences between the two groups. We were unable to detect any correlation between the extent of colon involvement and the subsequent incidence of pouchitis, long-term pouch function, and quality of life. Patients with left-sided colitis were older, had a relatively longer duration of disease, and were at increased risk for postoperative small bowel obstruction as compared to patients with pancolitis.

Adult↗