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Biomedical subjects

Jon S Thompson

Publications and source records attributed to Jon S Thompson.

At least 19 recordsLinked to original sources
PubMed2006

Watchful waiting vs repair of inguinal hernia in minimally symptomatic men: a randomized clinical trial.

CONTEXT: Many men with inguinal hernia have minimal symptoms. Whether deferring surgical repair is a safe and acceptable option has not been assessed. OBJECTIVE: To compare pain and the physical component score (PCS) of the Short Form-36 Version 2 survey at 2 years in men with minimally symptomatic inguinal hernias treated with watchful waiting or surgical repair. DESIGN, SETTING, AND PARTICIPANTS: Randomized trial conducted January 1, 1999, through December 31, 2004, at 5 North American centers and enrolling 720 men (364 watchful waiting, 356 surgical repair) followed up for 2 to 4.5 years. INTERVENTIONS: Watchful-waiting patients were followed up at 6 months and annually and watched for hernia symptoms; repair patients received standard open tension-free repair and were followed up at 3 and 6 months and annually. MAIN OUTCOME MEASURES: Pain and discomfort interfering with usual activities at 2 years and change in PCS from baseline to 2 years. Secondary outcomes were complications, patient-reported pain, functional status, activity levels, and satisfaction with care. RESULTS: Primary intention-to-treat outcomes were similar at 2 years for watchful waiting vs surgical repair: pain limiting activities (5.1% vs 2.2%, respectively; P = .06 [corrected]); PCS (improvement over baseline, 0.29 points vs 0.13 points; P = .79). Twenty-three percent of patients assigned to watchful waiting crossed over to receive surgical repair (increase in hernia-related pain was the most common reason offered); 17% assigned to receive repair crossed over to watchful waiting. Self-reported pain in watchful-waiting patients crossing over improved after repair. Occurrence of postoperative hernia-related complications was similar in patients who received repair as assigned and in watchful-waiting patients who crossed over. One watchful-waiting patient (0.3%) experienced acute hernia incarceration without strangulation within 2 years; a second had acute incarceration with bowel obstruction at 4 years, with a frequency of 1.8/1000 patient-years inclusive of patients followed up for as long as 4.5 years. CONCLUSIONS: Watchful waiting is an acceptable option for men with minimally symptomatic inguinal hernias. Delaying surgical repair until symptoms increase is safe because acute hernia incarcerations occur rarely.Clinical Trials Registration ClinicalTrials.gov Identifier: NCT00263250.

Adult↗
PubMed2005

Postoperative short bowel syndrome.

BACKGROUND: Unanticipated massive resection after intraabdominal procedures is an increasing cause of short bowel syndrome (SBS). Our aim was to determine the frequency and potential mechanisms of postoperative SBS. STUDY DESIGN: We reviewed retrospectively the clinical course of 210 adult patients with SBS evaluated over a 20-year period. RESULTS: Fifty-two (25%) patients had postoperative SBS. The initial operations included colectomy (n=20), hysterectomy (n=8), appendectomy (n=5), gastric bypass (n=5), and other (n=14). Intestinal obstruction (n=38) was the most common reason for resection leading to SBS, either from adhesions (n=26) or volvulus (n=12). Postoperative intestinal ischemia led to resection in 14 patients. SBS occurred from 1 day postoperatively to years later, with 16 (30%) intestinal resections occurring within 1 month. Patients undergoing resection for intestinal ischemia were more likely to undergo resection during the first month than were patients with adhesions and volvulus (86% versus 4% and 25%,respectively, p < 0.05): Patients undergoing resection for ischemia and volvulus were more likely to have remnant length<60 cm compared with those with adhesions (57% and 58% versus 23%, respectively, p < 0.05). Patients undergoing resection for adhesive obstruction were more likely to undergo multiple resections. Thirty-five (67%) patients required longterm parenteral nutrition. Seven (13%) patients died, three in the early postoperative period and four from complications of SBS. CONCLUSIONS: SBS is a potential postoperative complication of intraabdominal procedures and accounts for a considerable proportion of tertiary referrals for SBS. Surgical treatment of postoperative obstruction after common surgical procedures is the most frequent cause. Preventing adhesions, avoiding technical errors, diagnosing a potentially ischemic intestine in a timely manner, and approaching the frozen abdomen cautiously are important strategies for preventing this condition.

Adolescent↗
PubMed2005

Gallbladder pathology in morbid obesity.

BACKGROUND: Obese patients are at increased risk for biliary disease. The prevalence and type of gallbladder pathology in morbidly obese patients was evaluated, and compared with a non-obese control group. METHODS: A consecutive series of obese patients (n=478) who had undergone bariatric surgery with concurrent routine cholecystectomy and a consecutive group of organ donors (n=481) were compared. Gallbladder pathology was defined as: cholelithiasis, cholecystitis, cholesterolosis, or normal pathology. RESULTS: Mean age of obese patients and of donors was 42 +/- 9 and 43 +/- 17 years respectively and mean BMI was 52 +/- 10 and 27 +/- 7 kg/m2 respectively, P<0.05. There were more females in the obesity group (88% vs 47%, P<0.0001). 31% of obese patients and 7% of controls had a previous cholecystectomy (P<0.0001). 21% of the obese and 72% of the controls had normal gallbladder pathology (P<0.0001). Overall, obese patients had a higher incidence of cholelithiasis (25% vs 5%, P<0.0001), cholecystitis (50% vs 17%, P<0.0001), and cholesterolosis (38% vs 6%, P<0.0001) compared with controls. Obese patients with BMI <50 were more likely than those with BMI > or =50 to have normal gallbladder pathology (27% vs 14%, P<0.001). Female patients were more likely to have undergone previous cholecystectomy than males in both the obese group (34% vs 11%, P<0.001) and the control group (12% vs 2%, P<0.0001). Normal pathology was more common in male patients (80% vs 63%, P<0.0001) and patients <50 years (76% vs 66%, P<0.05) in the control group. CONCLUSIONS: Obese patients have an increased incidence of benign gallbladder disease than a group of controls, and the relative risk appears to be positively correlated with the level of increase in the BMI. Obesity appears to change the effect of age and gender on gallbladder pathology.

Adolescent↗
PubMed2005

The use and modification of clinical pathways to achieve specific outcomes in bariatric surgery.

Clinical pathways are promoted for standardizing patient care and decreasing resource use without compromising outcome. Once established, we hypothesized that clinical pathways can then be used to modify patient care to achieve specific goals. Our aim was to evaluate a clinical pathway for the bariatric surgical patient that was initially designed to standardize care and later altered to modify the postoperative course. We retrospectively reviewed 150 consecutive patients undergoing open gastric bypass by a single surgeon. The first 50 patients were managed without a formal pathway, (group I). The next 50 were managed with a pathway that standardized care in order to reduce length of stay (LOS), (group II). For the final 50 patients, the pathway was modified to shorten nasogastric decompression time (group III). Patient information, blood loss (EBL), operative time, length of stay (LOS), nasogastric decompression, 30-day complication rates, and early readmissions were reviewed. The groups were similar with respect to gender, age, body mass index, American Society of Anesthesiologists (ASA) classification, and EBL. Operative time was significantly less in groups II and III compared to group I (82% and 68% vs. 38% <180 minutes, P < 0.05). LOS was shorter in groups II and III compared to group I (62% and 42% vs. 20% with a 4-day LOS, P < 0.05). Duration of nasogastric tube decompression was successfully decreased in group III when compared to groups I and II (76% vs. 14% and 6% 1 day or less, P < 0.05). Complication rates were significantly lower in group III as well (14% vs. 36% and 28%, P < 0.05). Standardizing patient care with a clinical pathway decreases LOS after bariatric surgery. An established clinical pathway can then be used to further modify patient care in order to achieve specific goals, such as shortened time of nasogastric decompression. This goal was accomplished without compromising patient outcome.

Adult↗
PubMed2004

Modulation of FAK, Akt, and p53 by stress release of the fibroblast-populated collagen matrix.

BACKGROUND: Fibroblast survival in a three-dimensional collagen matrix is dependent in part upon the rigid anchorage of the matrix to tissue culture plastic. We hypothesized that focal adhesion kinase (FAK) and protein kinase B (Akt) would be activated and that the p53 level would be low in the rigidly anchored (attached) collagen matrix; loss of anchorage (detachment) was hypothesized to have the opposite effects. MATERIALS AND METHODS: Human foreskin fibroblasts were cultured in attached bovine collagen matrices for 48 h before detachment as free-floating matrices. At various time points postrelease, matrix lysates were blotted for the proteins of interest, and the terminal deoxynucleotidyltransferase-mediated dUTP nick-end label assay was performed on both whole matrices and cytospin preparations. Irradiated monolayer fibroblasts were used as positive controls for the amount of p53 protein. RESULTS: Terminal deoxynucleotidyltransferase-mediated dUTP nick-end label positivity in attached versus detached matrices (at 24 h post detachment) was 0.7 +/- 03 versus 5.3 +/- 1.7% (P < 0.05, unpaired t test). FAK and Akt were phosphorylated (activated) in the attached matrix; there was a near complete of loss of both activated forms within 4 h of matrix detachment. Irradiated monolayer fibroblasts had increased levels of p53, mdm2, and p21. In contrast, the p53, mdm2, and p21 levels were just at the level of detection in the attached matrix, but were induced 5- to 10-fold within 2-4 h after matrix detachment. CONCLUSIONS: FAK and Akt are activated in the attached fibroblast-populated collagen matrix whereas the p53 level is relatively low; matrix detachment downregulates FAK and Akt activity and induces p53. The state of mechanical anchorage of the collagen matrix regulates the survival of embedded fibroblasts through a mechanism which may involve FAK.

Adhesiveness↗
PubMed2004

Wound splinting modulates granulation tissue proliferation.

Attachment of the extracellular matrix to a substratum is important for fibroblast survival and proliferation in three-dimensional in vitro culture systems. We hypothesized that wound matrix attachment in a wound splinting model would modulate wound cell proliferation in vivo. Male rats were excisionally wounded on the dorsum, and a splint was sutured to the wound edge. In one experiment (N = 12), 6 rats were desplinted on day 5, and then all were sacrificed 24 h later, 6 h after 5-bromo-2'-deoxyuridine (BrdU) injection. In the second experiment (N = 18), 6 rats each were desplinted, desplinted with wound edge release, or not disturbed, followed by BrdU injection and sacrifice 24 h later. BrdU-labeled nuclei were quantified on frozen sections of granulation tissue, cut at three different levels. In the first experiment, the percentage of BrdU-positive nuclei per high power field (hpf) in the splinted vs. desplinted animals was 6.15 +/- 2.45 (S.D.) vs. 3.03 +/- 1.58%* p<0.001, ANOVA. In the second experiment, the number of BrdU-positive per hpf was 33.1 +/- 17.4 vs. 14.5 +/- 17.1 vs. 10.2 +/- 9.1* (splinted vs. desplinted vs. desplinted/released); *p<0.001 [analysis of variance (ANOVA)]. Removal of the wound splint decreased the rate of BrdU-labeled cells in the granulation tissue by approximately 50%; complete disruption of wound matrix attachment may have decreased this rate even further. Wound cell proliferation is modulated by lateral attachment of the wound matrix.

Analysis of Variance↗
PubMed2004

Altered olfactory acuity in the morbidly obese.

BACKGROUND: Obese individuals have been reported to have a heightened desire for and ability to identify sweets when compared with leaner persons. Smell, like taste, may also be altered in obese persons compared with leaner subjects. This study was designed to determine if the sense of smell is different between morbidly obese and moderately obese individuals. METHODS: 101 adult volunteers undergoing preoperative evaluation completed the 12-item Cross-Cultural Smell Identification Test (CC-SIT) before surgical intervention. Age, BMI, and smoking history were also obtained. RESULTS: 101 subjects completed the preoperative CC-SIT (87 female, 14 male). Mean age of the subjects was 40 +/- 12 years. Mean BMI was 42.5 +/- 12.5 kg/m(2). 46 subjects (46%) had a BMI >45. 21 were smokers (21%). 9 subjects (9%), all female non-smokers, had a CC-SIT score representing olfactory dysfunction. Subjects with BMI >45 were more likely to have olfactory dysfunction than subjects with BMI <45 (16% vs 4%, P <0.05). CONCLUSION: Morbidly obese individuals are more likely than moderately obese individuals to demonstrate CC-SIT scores consistent with olfactory dysfunction. The reason for this is unclear but is probably related to metabolic changes occurring in morbidly obese individuals.

Adult↗
PubMed2003

Temporal patterns of postoperative complications.

HYPOTHESIS: A variety of major complications occur after intra-abdominal operations. Knowledge of when specific complications occur during the postoperative period would be useful in their diagnosis, prevention, and management. Our aim was to determine the incidence of major complications during specific postoperative intervals. DESIGN: One thousand twenty-one patients undergoing intra-abdominal operations were studied postoperatively as part of a randomized clinical trial. Thirteen defined major complications were sought at the following specific intervals: less than 1, 1 through 3, 4 through 7, and 8 through 30 days after the operation. SETTING: Cooperative trial from 15 Veterans Affairs medical centers. INTERVENTIONS: Intra-abdominal aortic, gastric, biliary, and colonic procedures. MAIN OUTCOME MEASUREMENTS: Major postoperative complications. RESULTS: Four hundred thirty-five major complications were diagnosed within 30 days of the patients' being operated on. Seventy-four (17%) occurred within 1 day, 185 (43%) between 1 and 3 days, 72 (17%) between 4 and 7 days, and 104 (24%) between 8 and 30 days. Three deaths (8%) occurred within 1 day, 3 (8%) in 1 through 3 days, 4 (11%) in 4 through 7 days, and 27 (73%) in 8 through 30 days. The greatest risk of hypotension (43%), myocardial infarction (47%), and respiratory depression (55%) was within 1 day. The highest incidence of congestive heart failure (46%), pulmonary embolus (50%), and respiratory failure (76%) occurred at 1 through 3 days. Pneumonia (38%) was most common at 4 through 7 days. Cerebrovascular accident (53%) and sepsis (71%) occurred preponderantly at 8 through 30 days. Renal failure had a bimodal distribution with maxima at 1 through 3 days (31%) and 8 through 30 days (56%). The risk of cardiac arrhythmia and gastrointestinal tract bleeding was similar throughout all intervals. CONCLUSIONS: While major complications occur throughout the postoperative period, the highest incidence is 1 through 3 days after the operation. However, specific complications occur in the following distinct temporal patterns: early postoperative, several days after the operation, throughout the postoperative period, and in the late postoperative period. Knowledge of these patterns should aid clinical management.

Aged↗
PubMed2003

Short bowel syndrome and Crohn's disease.

Patients with Crohn's disease are at high risk for recurrent disease and often undergo multiple operations. Our aims were to evaluate surgical management and outcome of patients with Crohn's disease who develop short bowel syndrome (SBS) and to identify factors leading to this complication. We reviewed the records of 170 adult patients with SBS evaluated over a 20-year period. Thirty (18%) had Crohn's disease. SBS was defined as an intestinal remnant less than 180 cm with associated malabsorption. There were 20 women and 10 men ranging in age from 18 to 62 years. Eighteen (60%) presented initially with ileocolonic disease, seven (23%) with colonic disease, and five (17%) with small intestinal disease. The interval from initial diagnosis to development of SBS ranged from 2 to 32 years, with 21 patients (71%) having an interval greater than 15 years. The number of resections leading to SBS varied from 2 to 12 with 24 patients (80%) having four or fewer resections. Nineteen patients (63%) had an ostomy. Small intestinal remnant length was less than 60 cm in 10 patients, 60 to 120 cm in six patients, and greater than 120 cm in 14 patients. Only one patient underwent stricturoplasty before developing SBS. Five patients were initially diagnosed as having ulcerative colitis and underwent a pouch procedure, which was subsequently resected. Twenty patients (67%) required parenteral nutrition. Three patients have undergone reversed intestinal segment to slow intestinal transit. Two patients underwent intestinal transplantation. Two patients have died: one from parenteral nutrition-related liver failure and the other after intestinal transplantation. Crohn's disease remains a common cause of SBS. Aggressive resectional therapy, surgical complications, and errors in initial diagnosis contribute to development of SBS in these patients. Selected patients are candidates for surgical therapy for SBS.

Adolescent↗
PubMed2003

Wound splinting regulates granulation tissue survival.

PURPOSE: Fibroblast survival within an in vitro collagen matrix is dependent on matrix anchorage to a rigid substratum. The purpose of this study was to determine whether granulation tissue survival in vivo also is dependent on matrix anchorage. We hypothesized that splinting an excisional wound (i.e., anchoring the wound edges) would promote granulation tissue survival and that desplinting a splinted wound would produce granulation tissue apoptosis. METHODS: Eighteen Wistar rats (3 months, 350 g) underwent excisional wounding (2 x 2 cm, dorsal skin) with immediate wound splinting (a metal template affixed with sutures) on day 0. On day 6, rats (n = 6 per group) underwent splint removal (desplinted), splint removal with circumferential incision of the wound edge (desplint/release), or no intervention (splinted); sacrifice of all animals was on day 7. Frozen sections of granulation tissue were stained with TUNEL or H and E; data were analyzed with ANOVA and the unpaired t test. RESULTS: The cross-sectional and surface area of the desplinted and desplint/release granulation tissue both decreased compared to the splinted granulation tissue (*P < 0.05). The nuclear density of the desplint/release granulation tissue was 25% less compared to the splinted granulation tissue (*P < 0.05). The desplinted and desplint/release apoptotic rates were twice and >10x greater than the splinted apoptotic rate, respectively (*P < 0.05). CONCLUSIONS: The rate of cell death in a splinted wound (an in vivo equivalent of an anchored FPCM) is minimal to nil, which is consistent with our hypothesis. Desplinting and releasing the wound edge of a previously splinted wound (the in vivo equivalent of a detached FPCM) results in granulation tissue regression and a large increase in apoptosis. Desplinting a wound alone results in changes somewhat intermediate to the splinted and desplint/release conditions. Loss of wound anchorage acutely promotes granulation tissue apoptosis.

Animals↗
PubMed2003

New and emerging therapies for short bowel syndrome in children.

This review provides an overview of traditional as well as emerging therapies useful in the management of pediatric short bowel syndrome. Pediatric short bowel syndrome is relatively uncommon; however, when it does occur, it presents a unique challenge to medical care providers. The use of parenteral and enteral nutrition to maximize growth and enhance intestinal adaptation so as to increase absorptive surface area has been the primary focus of therapy. In recent years, the advent of pharmacologic advances, including the use of antibacterial drugs, anti-motility drugs and hormonal therapies, has had a significant impact on this condition. At times, surgery may be indicated for dealing with complications, or providing alternative therapy such as transplantation. With ongoing research, it is likely that improved pharmacologic therapy will be available for enhanced intestinal adaptation, control of gut motility, treatment of small bowel bacterial overgrowth, and treatment of rejection following small intestinal transplantation.

Bacteria↗
PubMed2002

Granulation tissue regression induced by musculocutaneous advancement flap coverage.

BACKGROUND: Clinical experience suggests that granulation tissue may be inhibited by coverage with a musculocutaneous flap. We hypothesized that coverage of an open wound with a musculocutaneous flap would result in regression and apoptosis of the wound's granulation tissue. METHODS: In the first experiment, 32 rats underwent excisional wounding; 16 underwent musculocutaneous flap coverage of their granulation tissue on postwounding day 8, and then 16 rats (8 controls + 8 flaps) were killed on both postwounding days 10 and 12 (2 and 4 days after the flap procedure, respectively). In the second experiment, 18 rats were wounded, and on postwounding day 5 the rats underwent flap coverage (n = 6), wound edge release/mobilization (the first step of the flap procedure) without flap coverage (n = 6), or dressing change only (n = 6); all rats were killed on postwounding day 6 (24 hours after the secondary intervention). Apoptosis was quantified with the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay. RESULTS: Placement of a musculocutaneous flap over an 8-day-old excisional wound in the first experiment increased the apoptotic rate in the granulation tissue from 0% to 1% (controls) to 5% to 10% at both 2 and 4 days after flap coverage (P <.05). Cell population density decreased 50% in the flap-covered granulation tissue compared with the controls (P <.05). In the second experiment, circumferential release of the granulation tissue resulted in an equivalent increase in granulation tissue apoptosis over controls compared to that induced by the full flap procedure. CONCLUSIONS: Coverage of established granulation tissue with a musculocutaneous flap resulted in histologic regression of the wound's granulation tissue after 2 to 4 days of flap coverage and induced at least a 5-fold increase in the apoptotic rate of the granulation tissue. Releasing the wound edge increased granulation tissue apoptosis to a level equivalent to that produced by the musculocutaneous flap procedure, suggesting that alteration of the wound's mechanical environment is responsible for the acute induction of apoptosis in this model.

Animals↗
PubMed2002

Short bowel syndrome in the elderly.

BACKGROUND: The need for massive intestinal resection in the elderly presents an ethical dilemma. The mortality rate for elderly patients who undergo this procedure is high, and quality of life with the short bowel syndrome (SBS) in this group is often questioned. This study evaluated the clinical outcome of patients >70 years of age who underwent intestinal resection leading to SBS. METHODS: This was a retrospective study of 23 patients ranging in age from 70 to 92 years, who were evaluated over a 20-year period. RESULTS: There were 11 (48%) early postoperative deaths. Parenteral nutrition (PN) was required for 8 of 12 discharged patients. Five (63%) of the 8 remained on PN permanently, and 3 were transitioned to enteral nutrition (EN). Three patients (PN = 2, EN = 1) died within a year of resection. Four (67%) of 6 patients surviving 5 years received EN only. Five of 10 patients with remnant length <120 cm were discharged, all on PN. PN was later discontinued in 2 patients. Seven (54%) of 13 patients with remnants > 120 cm were discharged; 3 of the 7 remained on PN. Resection was performed for mesenteric vascular disease (n = 13), radiation or cancer (n = 6), and other benign conditions (n = 4). Underlying diagnosis did not influence mortality rate or need for PN. Intestinal continuity was restored in 3 of the 8 patients discharged with an ostomy. Stricturoplasty was performed in 2 patients to improve intestinal function. CONCLUSIONS: Massive resection in the elderly has a high early mortality rate. Long-term survival is achieved in 50% of discharged patients, especially if they can transition to full EN. Nutritional prognosis is influenced by remnant length more than by underlying disease. Despite their advanced age, these patients are often candidates for further surgical procedures to improve intestinal function.

Journal Article↗
PubMed2002

The role of epidural analgesia and anesthesia in surgical outcomes.

Recent clinical evidence suggests that EAA used in combination with general anesthesia has a beneficial effect on surgical outcome compared with general anesthesia and systemic analgesia. Those complications with clear evidence of a reduced incidence in prospective, randomized studies are shown in Table 2. The benefits are greatest in high-risk patients who receive thoracic epidural blockade with local anesthetic agents. Besides reducing the incidence of certain major complications, the adjunctive use of EAA reduces ICU care, hastens recovery, and has cost savings.

Analgesia, Epidural↗