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Biomedical subjects

John F Sweeney

Publications and source records attributed to John F Sweeney.

18 recordsLinked to original sources

Impact of morbid obesity on outcome of laparoscopic splenectomy.

BACKGROUND: Because of the obesity epidemic, surgeons are operating on morbidly obese patients in increasing numbers. The aim of this study was to evaluate the impact of morbid obesity on the outcome of laparoscopic splenectomy. METHODS: The study group consisted of 120 consecutive patients who underwent laparoscopic splenectomy for benign and malignant disease from March 1996 to May 2005. These patients were retrospectively divided into three groups. Group 1 had a body mass index (BMI) < 30. Group 2 patients had a BMI > or = 30 and < 40 and were considered obese. Group 3 had a BMI > or = 40 and were considered morbidly obese. Data including surgical approach (laparoscopic vs. hand-assisted), operative time, conversion rate, estimated blood loss, splenic weight, length of stay, time to tolerate a diet, pathologic diagnosis, complications, and mortality were recorded. RESULTS: Complete data were available for evaluation of 112 patients of whom 73 (65%) had a BMI < 30, 32 (29%) had a BMI > or = 30 and < 40, and 7 (6%) had a BMI > or = 40. The most frequent indication for splenectomy in all three groups was idiopathic thrombocytopenic purpura (ITP). The operative times were significantly higher in patients with a BMI > 40. Conversion rates were also higher in this group, although this did not reach statistical significance. Patients with a BMI > 30 experienced similar complication rates when compared with patients with a BMI < 30. Only when patients had a BMI > 40 did they experience more complications. CONCLUSIONS: Laparoscopic splenectomy was performed safely in obese patients (BMI > 30) with similar results to those of nonobese patients. Only in morbidly obese patients (BMI > 40) do outcomes and complications appear to be affected. Obesity should not be a contraindication to laparoscopic splenectomy.

Adult↗

Diagnosis and management of diverticulitis and appendicitis.

Diverticulitis and appendicitis are common infections of the gastrointestinal tract that require urgent medical and surgical attention. Successful management of these conditions requires a multidisciplinary approach among primary care providers, gastroenterologists, surgeons, and radiologists. The diagnosis of appendicitis, in particular, can be difficult. Advances in radiographic imaging have improved the diagnostic accuracy in these infections. Minimally invasive surgical techniques have improved the patient's postoperative recovery when surgery is necessary in the management of these conditions.

Appendicitis↗

Laparoscopic colon resection early in the learning curve: what is the appropriate setting?

INTRODUCTION: Laparoscopic colon resection (LCR) is a safe and effective treatment of benign and malignant colonic lesions. There is little question that a steep learning curve exists for surgeons to become skilled and proficient at LCR. Because of this steep learning curve, debate exists regarding the appropriate hospital setting for LCR. We hypothesize that outcomes of LCR performed early in the learning curve at a regional medical center (New Hanover Regional Medical Center; NHRMC) and a university medical center (Baylor College of Medicine; BCM) would not be significantly different. METHODS: The first 50 consecutive LCRs performed at each institution between August 2001 and December 2003 were reviewed. Age, mean body mass index (BMI), gender, history of previous abdominal surgery (PAS), operative approach [laparoscopic (LAP) versus hand/laparoscopic assisted (HAL)], conversions (Conv), operative time (OR time), pathology (benign vs. malignant), lymph nodes (LN) harvested in malignant cases, length of stay (LOS), morbidity and mortality were obtained. Continuous data were expressed as mean +/- SD. Data were analyzed by chi, Fisher exact test, or t test. RESULTS: NHRMC patients were on average older females with a higher incidence of PAS. A LAP approach was more frequently performed at BCM (86%), whereas HAL was used more frequently at NHRMC (24%). Conversions to open were similar at both institutions (12%). Benign disease accounted for the majority of operations at both institutions. In cases of malignancy, more LN were harvested at BCM. OR time and LOS were shorter at NHRMC. Complication rates were similar between institutions. There were no anastomotic leaks or deaths. CONCLUSIONS: LCR can be performed safely and with acceptable outcomes early in the learning curve at regional medical centers and university medical centers. Outcomes depend more on surgeons possessing advanced laparoscopic skills and adhering to accepted oncologic surgical principles in cases of malignancy, than on the size or location of the healthcare institution.

Clinical Competence↗

Laparoscopic splenectomy: present status and future perspective.

Laparoscopic splenectomy has become widely accepted as the approach of choice for the surgical treatment of benign and malignant hematologic diseases. Advances in technology have led to better outcomes for the procedure, and have allowed surgeons to apply the technique to disease processes that were at one time felt to be contraindications to laparoscopic splenectomy. However, challenges still remain. There is a steep learning curve associated with the procedure. The development of cost-effective laparoscopic simulators to target the skills required for laparoscopic splenectomy and other laparoscopic procedures is essential. The advent of devices which isolate and seal the large blood vessels that surround the spleen have reduced intra-operative bleeding and minimized conversions to open splenectomy. Improvements in optics and instrumentation, as well as robotic technology, will continue to define the frontier of minimally invasive surgery, and further facilitate the acceptance of laparoscopic splenectomy for the treatment of benign and malignant hematologic diseases.

Animals↗

Value of laparoscopy in the staging of pancreatic cancer.

Pancreatic cancer is a devastating disease that swiftly robs patients of both quality and quantity of life. It is the fourth leading cause of cancer death in the United States. In 2003, there were 31,860 reported new cases with 31,270 deaths occurring due to lack of effective therapy. Eighty percent of patients present with either advanced local or metastatic disease. Dynamic contrast-enhanced computed tomography (CT) has become the current staging test of choice. Laparoscopic staging of pancreatic tumors with the addition of ultrasound can reveal intraparenchymal hepatic metastases, small peritoneal metastases, and critical retroperitoneal tumor-vessel relationships approaching the accuracy of open exploration to determine resectability without significantly increasing morbidity or mortality. However, given the current accuracy of high-quality CT, the routine use of diagnostic laparoscopy in pancreatic cancer is not warranted. Diagnostic laparoscopy is recommended in select patients with primary tumors greater than 4 cm, tumors in the body or tail of the pancreas, patients with equivocal findings of metastasis on CT, ascites, or clinical or laboratory findings suggesting advanced disease such as marked weight loss, hypoalbuminemia, and elevated CA 19-9.

Humans↗

Eotaxin and obesity.

CONTEXT: Asthma and obesity incidence is increasing worldwide, and asthma is often more severe in the obese. Eotaxin, a CC chemokine, is important in extrinsic asthma, an inflammatory disorder. OBJECTIVE: Our objective was to examine the relation between eotaxin and obesity. DESIGN: We conducted a comparison study of eotaxin in mice fed high-fat vs. standard chow diet for 26 wk, in obese vs. lean humans, in obese humans before and after 4-6 wk of weight loss, and in sc vs. visceral adipose tissue from patients undergoing bariatric surgery. SETTING: Our clinical study occurred in an outpatient weight loss program. PATIENTS: Patients were obese adults with metabolic syndrome (n = 40) and nine morbidly obese bariatric surgery patients. INTERVENTION: Intervention was a very-low-calorie diet. MAIN OUTCOME MEASURES: We assessed circulating eotaxin and eotaxin mRNA levels in adipose tissue. RESULTS: Serum eotaxin levels were significantly higher in obese mice, and adipose mRNA levels correlated positively with serum eotaxin levels. Adipose tissue explants from obese mice showed increased secretion of eotaxin compared with explants from lean mice. In obese patients, plasma eotaxin levels were significantly higher than in lean controls and significantly reduced after weight loss, and eotaxin mRNA levels were 4.7-fold higher in visceral than sc adipose tissue. CONCLUSIONS: Circulating eotaxin and eotaxin mRNA levels in visceral adipose tissue were increased in obesity in mice and humans. Adipose tissue explants secrete eotaxin, and the stromal/vascular component of adipose tissue seems to be the predominant source of eotaxin. Diet-induced weight loss in humans led to reduction in plasma eotaxin levels, demonstrating that clinical interventions that target obesity can modulate systemic eotaxin levels.

3T3 Cells↗

Defining the learning curve for laparoscopic splenectomy for immune thrombocytopenia purpura.

BACKGROUND: The current study was undertaken to define the learning curve for laparoscopic splenectomy (LS) in patients with immune thrombocytopenic purpura (ITP). METHODS: The data of 50 patients who underwent LS for ITP between March 1996 and February 2003 were reviewed. Patients were divided into sequential groups of 10. Operative time, estimated blood loss, conversion to open procedure, length of stay (LOS), time to oral intake, complications, and mortality rates were analyzed. RESULTS: The mean OR time in the 3rd, 4th, and 5th groups of 10 were significantly shorter than the 1st and 2nd groups of 10. There were no significant differences in estimated blood loss, LOS, or time to oral intake between the groups. Three conversions to open splenectomy occurred; one each in the 2nd, 3rd, and 4th groups of 10. Complications were evenly distributed between groups. There were no deaths. CONCLUSION: The learning curve for LS in patients with ITP is a minimum of 20 cases.

Adult↗

Sulfur mustard primes phagocytosis and degranulation in human polymorphonuclear leukocytes.

Sulfur mustard (2,2'-bis-chloroethyl-sulfide; SM) is a chemical warfare vesicant that causes debilitating skin lesions. Although a great deal of work has focused on the direct effects of SM exposure on the epithelium, it is unclear how much the inflammatory response, induced by exposure, contributes to lesion pathogenesis. Keratinocytes exposed to SM express a number of inflammatory mediators and elicit a cellular infiltrate consisting largely of polymorphonuclear leukocytes (PMN). PMN infiltration into SM lesions occurs as early as 30 min and peaks after several hours postexposure, and, despite the relatively short half-life of SM, PMN infiltrating a lesion could be exposed to micromolar concentrations of the agent. Previously, we have shown that exposure to low doses of sulfur mustard prime oxidative function in human PMN. The current study was undertaken to evaluate the effects of low-dose SM exposure on PMN phagocytosis, degranualtion and chemotaxis. PMN exposed to low doses of SM (50-200 microM) showed a dose-dependent enhancement of phagocytic function. Exocytosis of PMN azurophilic and specific granules [determined by analysis of granule-specific intravesicular receptors, Interleukin 10 receptor (IL-10R) and CD63] was also enhanced by SM exposure. Finally, we examined the effect of SM as a chemoattractant for PMN and show that SM is not itself a chemotaxin. These results suggest that SM injury may, in part, be caused by normal inflammatory function, and that therapeutic strategies aimed at down-regulating PMN activation could lessen the severity of SM injury and the time required for its resolution.

Cell Degranulation↗

Laparoscopic splenectomy--a review.

Laparoscopic splenectomy has become the standard approach in many institutions when splenectomy is indicated for benign hematologic disease and has gained acceptance in patients with malignant hematologic disease and splenomegaly. It is a technically difficult procedure and is associated with a steep learning curve, with operative times initially longer than those associated with open splenectomy. However, technical advancements such as hand-assisted laparoscopic splenectomy have facilitated increased acceptance of laparoscopy as an approach that is superior to open splenectomy, even in patients with malignant hematologic disease and/or splenomegaly. When compared to open splenectomy, laparoscopic splenectomy is associated with shorter postoperative hospitalization and improved cosmesis.

Hematologic Diseases↗

Intravenous methylene blue as an aid to intraoperative localization and removal of the adrenal glands during laparoscopic adrenalectomy.

BACKGROUND: We hypothesized that intravenous methylene blue will facilitate adrenal gland identification and resection during laparoscopic adrenalectomy. METHODS: Five mini-Hanford pigs were anesthetized and monitored per an approved Internal Review Board protocol. Timing of color changes in the adrenals was recorded after administering methylene blue at three different doses: 2.5 mg/kg, 5.0 mg/kg, and 7.5 mg/kg. The time required for laparoscopic adrenalectomy with and without methylene blue was recorded. RESULTS: No color change occurred after the 2.5 mg/kg dose. For the 7.5 mg/kg versus the 5.0 mg/kg dose there was a more rapid bluish color change (mean time, 1.89 minutes versus 3.45 minutes; P = 0.03) and a longer duration of bluish color change (mean time, 12.20 minutes versus 6.19 minutes; P = 0.01). Laparoscopic adrenalectomy using methylene blue resulted in a 34.5% faster median resection time (10.13 minutes versus 15.47 minutes). CONCLUSIONS: Methylene blue concentrates in the adrenal glands and facilitates identification and resection of the adrenal glands by a laparoscopic approach.

Adrenal Glands↗

101 laparoscopic splenectomies for the treatment of benign and malignant hematologic disorders.

BACKGROUND: Laparoscopic splenectomy (LS) is the surgical approach of choice for patients with hematologic disorders requiring splenectomy. Patients with idiopathic thrombocytopenic purpura (ITP) have normal to slightly enlarged spleens and benefit the most from LS. METHODS: We reviewed the perioperative outcomes in 101 patients who underwent LS between May 1996 and December 2002. Patients were divided into three groups--ITP, other benign, and malignant hematologic disorders--and compared. RESULTS: The ITP patients (n = 48) had significantly smaller spleens and operative times compared with the other groups. Splenomegaly in the other benign (n = 23) and malignant hematologic disorders (n = 30) groups was responsible for higher open conversion rates and greater need for hand-assisted laparoscopic splenectomy (HALS). CONCLUSIONS: Laparoscopic splenectomy and HALS can be performed with good results for benign and malignant hematologic disorders. The benefits of HALS are similar to LS, so there should be a low threshold for HALS in patients with large spleens.

Case-Control Studies↗

Low-dose sulfur mustard primes oxidative function and induces apoptosis in human polymorphonuclear leukocytes.

Although considerable work has focused on understanding the processes of direct tissue injury mediated by the chemical warfare vesicant, sulfur mustard (2,2'-bis-chloroethyl sulfide; SM), relatively little is known regarding the mechanisms of secondary injury caused potentially by the acute inflammatory response that follows SM exposure. Polymorphonuclear leukocytes (PMNs) play a central role in the initiation and propagation of inflammatory responses that, in some cases, result in autoimmune tissue damage. The potential for PMN-derived tissue damage following SM exposure may, in part, account for the protracted progression of the injury before it resolves. The current study was undertaken to evaluate the priming, oxidative function, and viability of PMN following exposure to low doses of SM such as those that might remain in tissues as a result of topical exposure. Our results demonstrate that doses of SM ranging from 25 to 100 microM primed PMN for oxidative burst in response to activation by fMLP, and that doses of SM ranging from 50 to 100 microM induced PMN apoptosis. Understanding the mechanisms through which SM directly affects PMN activation and apoptosis will be of critical value in developing novel treatments for inflammatory tissue injury following SM exposure.

Apoptosis↗

Laparoscopic splenectomy for chronic recurrent thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a serious hematologic disorder with a high rate of morbidity and mortality when it fails to go into remission. The primary treatment is total plasma exchange. The addition of corticosteroids, chemotherapeutic agents, or antiplatelet agents is of unproven benefit, and splenectomy has been offered as salvage therapy in refractory cases. We performed laparoscopic splenectomy (LS) on two patients with chronic refractory TTP. The early and late postoperative courses, including hematologic data, are presented here. The mean duration of surgery was 113 minutes and the mean estimated blood loss was 35 mL. Mean hospital stay was 1.5 days. The early postoperative platelet count showed an immediate rise in both patients. After 19 months and 16 months of follow-up, respectively, both patients remain in remission without further episodes of TTP. Laparoscopic splenectomy is a safe and effective therapy for patients with chronic relapsing and refractory TTP. The inherent benefits of the minimally invasive approach, its low morbidity, short hospital stay, and faster recovery, are significant advantages for these patients.

Adult↗

Laparoscopic pancreatic cystogastrostomy.

The purpose of the review was to evaluate the feasibility and outcome of laparoscopic pancreatic cystogastrostomy for operative drainage of symptomatic pancreatic pseudocysts. A retrospective review of all patients who underwent laparoscopic pancreatic cystogastrostomy between June 1997 and July 2001 was performed. Data regarding etiology of pancreatitis, size of pseudocyst, operative time, complications, and pseudocyst recurrence were collected and reported as median values with ranges. Laparoscopic pancreatic cystogastrostomy was attempted in 6 patients. Pseudocyst etiology included gallstone pancreatitis (3), alcohol-induced pancreatitis (2), and post-ERCP pancreatitis (1). The cystogastrostomy was successfully performed laparoscopically in 5 of 6 patients. However, the procedure was converted to open after creation of the cystgastrostomy in 1 of these patients. There were no complications in the cases completed laparoscopically and no deaths in the entire group. No pseudocyst recurrences were observed with a median followup of 44 months (range 4-59 months). Laparoscopic pancreatic cystgastrostomy is a feasible surgical treatment of pancreatic pseudocysts with a resultant low pseudocyst recurrence rate, length of stay, and low morbidity and mortality.

Adult↗

Hand-assisted laparoscopic splenectomy in patients with splenomegaly or prior upper abdominal operation.

BACKGROUND: Laparoscopic splenectomy (LS) in patients with significant splenomegaly or prior upper abdominal operation is technically challenging with a high conversion rate to open operation. We hypothesized that hand-assisted laparoscopic splenectomy (HLS) in this setting would improve operative (OR) outcomes without impacting post-OR ileus, length of stay, morbidity, or mortality, compared with LS. METHODS: All patients with splenomegaly (spleen weight > or = 500 g) or prior upper abdominal operation undergoing LS or HLS between March 1996 and June 2001 were reviewed. Nonparametric continuous variables were expressed as median and intraquartile range with statistical significance determined by Wilcoxon rank sum test. RESULTS: Of 41 patients reviewed, 22 underwent HLS, whereas 19 underwent LS. Median OR time for HLS was significantly less than for LS (161 minutes vs 212 minutes, P =.004). HLS was associated with a lower conversion rate (13.6% vs 36.8%, P =.08) and blood loss (325 mL vs 550 mL, P =.18) than LS, which approached statistical significance. HLS did not increase post-OR ileus, length of stay, morbidity, or mortality. CONCLUSIONS: HLS in patients with significant splenomegaly or prior upper abdominal operation significantly shortens OR time compared with LS without adversely impacting post-OR ileus, length of stay, morbidity, or mortality. In addition, HLS may be associated with a lower conversion rate and decreased blood loss.

Female↗

Rectal duplication cyst in an adult: the laparoscopic approach.

BACKGROUND: Rectal duplication cyst (RDC) is a rare congenital anomaly representing 1% to 8% of all intestinal duplications. The case presented here is the first report of the laparoscopic resection of an RDC. METHODS: We report the case of a 49-year-old white woman in whom a retrorectal cystic mass measuring 5 x 5.3 x 6 cm was diagnosed. The mass was completely resected by means of laparoscopic techniques. RESULTS: Pathologic findings revealed a cystic structure partially lined with squamous as well as respiratory- and gastrointestinal-type epithelium. Muscularis propria was identified in the outer portions of the wall of the specimen. No atypia or malignancy was identified. The overall findings were consistent with an RDC. CONCLUSIONS: Laparoscopic resection constitutes an excellent and patient-friendly approach to the management of large adult cystic duplication of the rectum.

Cysts↗

Laparoscopic management of colonic lipomas: a case report and review of the literature.

Colonic lipomas are infrequent lesions, yet they are the second most common benign lesions of the colon after benign adenomatous polyps. Their treatment ranges from observation to segmental colectomy and has been a matter of debate since Bauer first reported them in 1757. With the advent of new technologies, therapeutic options now include observation, endoscopic removal, laparoscopic removal, and traditional open surgery. We present a case of colonic lipoma presenting with indeterminate symptomatology, its workup, treatment outcome, and a review of the current literature.

Colonic Neoplasms↗