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Dive into the research topics where Michael J. Garren is active.

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Featured researches published by Michael J. Garren.


Obesity Surgery | 2004

Lessons learned from the first 100 cases in a new minimally invasive bariatric surgery program

Jon C. Gould; Michael J. Garren; James R. Starling

Background:Laparoscopic Roux-en-Y gastric bypass (LRYGBP) is a technically demanding procedure with a steep learning curve. Experienced laparoscopic surgeons and bariatric surgeons can learn from the outcomes and complications of their initial experience in LRYGBP.n Methods: Between August of 2002 and July of 2003, we performed our first 100 LRYGBPs. Our surgical technique involves the ante-colic, ante-gastric placement of the Roux-limb. A 21-mm circular stapler is used to create the gastrojejunostomy. The stapler anvil is placed transgastrically.n Results:The mean preoperative BMI was 49.7 kg/m2 (range 37-70). 12% of patients were male. Early complications (14%) included 3 leaks, 4 bleeding episodes and 2 gastrogastric fistulas. There was 1 peri-operative mortality and 1 conversion to laparotomy. Late complications (17%) included stenosis of the gastrojejunostomy which occurred in 14 patients. Leaks occurred more commonly in males (16% vs 1%, P<0.05). Elevated BMI was also found to be a risk factor for leak (BMI 58.7 leak vs 49.3 no leak, P<0.05). Stenosis was often associated with other complications such as leak or marginal ulcer. Stenosis responded well to endoscopic dilation. Co-morbid medical conditions responded to weight loss in all patients, regardless of initial BMI. Mean excess weight loss was 69% at 1 year, but varied according to preoperative BMI. Conclusions: Careful recording of patient outcomes and complications is important, particularly in a new minimally invasive bariatric surgery program. Review and analysis of specific complications may help to minimize the occurrence of similar subsequent complications.


Journal of Surgical Research | 2008

Vitamin D Status of Morbidly Obese Bariatric Surgery Patients

Emily Fish; Gretchen Beverstein; Diane Olson; Susan Reinhardt; Michael J. Garren; Jon C. Gould

BACKGROUND Abnormal vitamin D levels are common in bariatric surgery patients. The incidence of deficiencies and the response to therapy is not accurately delineated. The purpose of this study was to define the vitamin D status of patients who undergo either a malabsorptive (gastric bypass) or restrictive (adjustable gastric band) bariatric surgery both prior to and after surgery. METHODS A retrospective analysis was performed on patients to undergo bariatric surgery from July 2002 to February 2007. Serum levels of vitamin D (Vit D), parathyroid hormone (PTH), and calcium were analyzed. RESULTS Mean patient age was 45 y; 82% of patients were women. Of 127 total patients, 84% were Vit D deficient preoperatively. These patients had a higher preoperative body mass index (BMI) than those with normal Vit D levels on initial assessment (BMI 44 versus 50 kg/m(2), P < 0.01). A correlation was found between preoperative BMI and Vit D (r(2) = 0.12, P < 0.01) and PTH levels (r(2) = 0.07, P < 0.01). One year following gastric bypass surgery, 20% of patients with elevated PTH levels had normal Vit D levels. The incidence of observed deficiencies for adjustable gastric band versus gastric bypass did not differ statistically at any interval. CONCLUSIONS Morbidly obese patients seeking bariatric surgery are often deficient in Vit D, a fact that should be accounted for when evaluating the impact of bariatric surgery on Vit D levels. Elevated BMI and increasing degrees of obesity may be risk factors for both Vit D deficiency and secondary hyperparathyroidism. Despite normal Vit D levels, some gastric bypass patients continue to show elevated levels of PTH.


Surgical Endoscopy and Other Interventional Techniques | 2006

The impact of circular stapler diameter on the incidence of gastrojejunostomy stenosis and weight loss following laparoscopic Roux-en-Y gastric bypass.

Jon C. Gould; Michael J. Garren; Valerie Boll; James R. Starling

BackgroundGastrojejunostomy stenosis after laparoscopic Roux-en-Y gastric bypass is a common occurrence. The incidence varies widely among reported series. We evaluated the impact of circular stapler size on the rate of stenosis and weight loss.MethodsOur initial technique utilized a 21-mm circular stapler to construct the gastrojejunostomy. We switched to a 25-mm stapler after a large preliminary experience. Stenosis was confirmed by endoscopy in patients complaining of the inability to eat or excessive vomiting, and was defined as a gastrojejunostomy diameter less than that of a therapeutic endoscope (11-mm).ResultsStenosis occurred in 23 of 145 patients (15.9%) with a 21-mm gastrojejunostomy. Five of 81 patients with a 25-mm circular stapled anastomosis have developed a stenosis (6.2%, p = 0.03). Weight loss was similar for each sized stapler at 6 and 12 months.ConclusionsThe use of a 25-mm circular stapler in laparoscopic gastric bypass is preferable to a 21-mm stapler. The larger stapler is associated with a significantly decreased incidence of gastrojejunostomy stenosis without compromising early weight loss.


Surgery for Obesity and Related Diseases | 2012

Factors associated with readmission after laparoscopic gastric bypass surgery

Brian W. Hong; Edwin Stanley; Susan Reinhardt; Kristen Panther; Michael J. Garren; Jon C. Gould

BACKGROUND Studies have demonstrated that laparoscopic Roux-en-Y gastric bypass (RYGB) is associated with the greatest readmission rate among bariatric surgeries. Some readmissions might be avoidable. We sought to evaluate the risk factors for readmission in a high-volume bariatric surgery program at a university hospital in the United States. METHODS We performed a retrospective review of prospectively maintained data. Patients readmitted within 30 days of laparoscopic RYGB were randomly matched to control patients who had undergone RYGB in the same year but were not readmitted. The readmissions were categorized as technical complications (leak), wound infections, or malaise (nausea, dehydration, or benign abdominal pain). Patients with a wound infection treated in an outpatient setting were also evaluated and compared with the patients admitted with a wound infection. RESULTS From July 2002 to July 2008, 450 patients underwent RYGB. Readmission occurred in 42 patients (9%). Of these 42 patients, 6 were admitted with wound infections (14%), 18 (43%) with malaise, and 18 (43%) with technical complications. The patients admitted with wound infections were similar to their controls, except that they were more likely to have publicly funded insurance (Medicare or Medicaid) and more likely to present for medical attention to the emergency department after clinic hours. The patients admitted with malaise reported a greater pain score at discharge and were also more likely to have public health insurance than controls. The patients with technical complications did not differ from the control patients in any examined variable. CONCLUSIONS Patients with publicly funded insurance are at increased risk of readmission after RYGB. Outpatient mechanisms for managing wound infections and malaise might result in decreased readmissions.


Journal of Gastrointestinal Surgery | 2004

Laparoscopic gastric bypass results in decreased prescription medication costs within 6 months.

Jon C. Gould; Michael J. Garren; James R. Starling

The prevalence of obesity has reached epidemic proportions. The treatment of obesity-related health conditions is costly. Although laparoscopic gastric bypass is expensive, health care costs in obese patients should decrease with subsequent weight loss and overall improved health. Specifically, monthly prescription medication costs should decrease quickly after surgery. Fifty consecutive laparoscopic gastric bypass patients at a university-based bariatric surgery program were enrolled in the study. Medication consumption was prospectively recorded in a database. Patients’ monthly prescription (not over-the-counter) medication costs before surgery and 6 months postoperatively were calculated. Retail costs were determined by a query to drugstore.com, an online pharmacy. Generic drugs were selected when appropriate. Costs for diabetic supplies and monitoring were not included in this analysis. Patients were mostly female (86%). Mean body mass index preoperatively was 51 kg/m2. Mean excess weight loss at 6 months was 52%. Patients took an average of 3.7 prescription medications before surgery compared with 1.7 after surgery (P < 0.05). All patients took nonprescription nutritional supplements, including multivitamins, oral vitamin B12, and calcium postoperatively. Laparoscopic gastric bypass resulted in a significant improvement in comorbid health conditions as early as 6 months after surgery. In an unselected group of patients, this led to a substantial overall mean monthly prescription medication cost savings, especially in those with gastroesophageal reflux disease, hypertension, diabetes, and hypercholesterolemia.


Surgery for Obesity and Related Diseases | 2010

Effect of circular staple line buttressing material on gastrojejunostomy failure in laparoscopic Roux-en-Y gastric bypass.

Anna Ibele; Michael J. Garren; Jon C. Gould

BACKGROUND To determine the effect of bovine pericardium strip (BPS) reinforcement of the circular stapler on the gastrojejunostomy leak rates and staple line failure after laparoscopic Roux-en-Y gastric bypass (LRYGB) at a university hospital in the United States. Gastrojejunostomy leak after LRYGB is a devastating complication. Various techniques, including buttressing the gastrojejunostomy staple line with biomaterial, have been used in an effort to minimize leaks. METHODS A total of 350 consecutive patients underwent LRYGB without staple line buttressing. After this initial experience, BPS reinforcement of the gastrojejunostomy was conducted in 81 consecutive patients. BPS reinforcement was not used for the final 69 consecutive patients in this 500 patient series. Circular staple line failures (intraoperative immediate and complete failure of the anastomosis) and leaks were evaluated retrospectively. RESULTS Three leaks (and no intraoperative staple line failures) occurred in 419 patients without BPS buttressing, all in the first 100 cases of our experience, and 3 leaks and an anastomotic staple line failure occurred in the 81 patients with BPS buttressing (.7% versus 4.9%, P = .02). The body mass index and other potential leak risk factors did not differ between the 2 groups. CONCLUSION In our experience, buttressing of the circular staple line with BPS during LRYGB was associated with an increased staple line adverse event rate. BPS buttressing of the gastrointestinal circular staple lines should be used with caution.


Journal of Surgical Research | 2013

Diabetes remission and glycemic response to pre-bariatric surgery diet.

Steven M. Biro; Diane Olson; Michael J. Garren; Jon C. Gould

BACKGROUND Before bariatric surgery, some patients with type 2 diabetes mellitus (T2DM) experience improvement in blood glucose control and reduced insulin requirements while on a preoperative low-calorie diet (LCD). We hypothesized that patients who exhibit a significant glycemic response to this diet are more likely to experience remission of their diabetes in the postoperative period. MATERIALS AND METHODS Insulin-dependent T2DM patients undergoing bariatric surgery between August 2006 and February 2011 were eligible for inclusion. Insulin requirements at day 0 and 10 of the LCD were compared. Patients with a ≥ 50% reduction in total insulin dosage to maintain appropriate blood glucose control were considered rapid responders to the preoperative LCD. All others were non-rapid responders. We analyzed T2DM remission rates up to 1 y postoperatively. RESULTS A total of 51 patients met inclusion criteria and 29 were categorized as rapid responders (57%). The remaining 22 were considered non-rapid responders (43%). The two groups did not differ demographically. Rapid responders had greater T2DM remission rates at 6 (44% versus 13.6%; P = 0.02) and 12 mo (72.7% versus 5.9%; P < 0.01). In patients undergoing laparoscopic gastric bypass, rapid responders showed greater excess weight loss at 3 mo (40.1% versus 28.2%; P < 0.01), 6 mo (55.2% versus 40.2%; P < 0.01), and 12 mo (67.7% versus 47.3%; P < 0.01). CONCLUSIONS Insulin-dependent T2DM bariatric surgery patients who display a rapid glycemic response to the preoperative LCD are more likely to experience early remission of T2DM postoperatively and greater weight loss.


Archive | 2016

Laparoscopic Inguinal Hernia Repair Total Extraperitoneal (TEP) Approach

Michael J. Garren

Inguinal hernias are extremely common and can be repaired through a variety of open and laparoscopic techniques. The following chapter reviews our approach to the laparoscopic Totally Extraperitoneal Inguinal Hernia Repair.


Surgery | 2006

Laparoscopic gastric bypass: risks vs. benefits up to two years following surgery in super-super obese patients.

Jon C. Gould; Michael J. Garren; Valerie Boll; James R. Starling


Surgery for Obesity and Related Diseases | 2007

Impact of routine and long-term follow-up on weight loss after laparoscopic gastric bypass

Jon C. Gould; Gretchen Beverstein; Susan Reinhardt; Michael J. Garren

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Jon C. Gould

Medical College of Wisconsin

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James R. Starling

University of Wisconsin-Madison

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Gretchen Beverstein

University of Wisconsin-Madison

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Susan Reinhardt

University of Wisconsin-Madison

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Anna Ibele

University of Wisconsin-Madison

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Diane Olson

University of Wisconsin-Madison

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Edwin Stanley

University of Wisconsin-Madison

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Sarah E. Tevis

University of Wisconsin-Madison

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Steven M. Biro

University of Wisconsin-Madison

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Valerie Boll

University of Wisconsin-Madison

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