The gastric sleeve operation is the most popular operation for weight loss, but outcomes (weight loss results, complications) vary between different surgeons and programs. We offer a premier Orange County gastric sleeve program with an established record of excellent patient outcomes.*

Why Dr. Oliak?

What sets Dr. Oliak apart from others is his long record of excellent patient outcomes – outcomes after weight loss surgery vary, and Dr. Oliak’s rank among the best.*
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The Next Step

The next step to learn more about gastric sleeve surgery and our program is to attend a free, no obligation educational consultation with Dr. Oliak in Brea or Irvine.*
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Gastric Sleeve Outcomes – Weight Loss

Published Studies

There have been 100s of studies published on gastric sleeve weight loss, by 100s of surgeons, and the results are surprisingly variable. Some surgeons report average gastric sleeve weight loss to be as low as 40-50% EWL (EWL – excess weight loss, definition below), and some report average weight loss to be as high as 70-80% EWL.*
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This is a very large range – the difference between 40-50% EWL and 70-80% EWL is about 30 pounds for the typical patient with a starting BMI around 40, and more for higher BMI patients. There are several reasons for this variability, but the bottom line is that some surgeons achieve better weight loss results than other surgeons.*
Outcomes vary between surgeons
Why surgeon outcomes vary

Industry Average Weight Loss

Different surgeons report widely variable weight loss results, but what is the overall industry average weight loss for all surgeons? Gagner et al compiled weight loss data from 130 surgeons and 46,133 gastric sleeve operations and found overall average (industry average) gastric sleeve weight loss to be 55-59% EWL at 1-3 years after surgery (59.3% EWL at 1 year, 59.0% EWL at 2 years, 54.7% EWL at 3 years).*
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Dr. Oliak’s Weight Loss Statistics

Orange County gastric sleeve surgeon Dr. Oliak’s weight loss statistics are better than the industry averages. Dr. Oliak’s patients average 75-80% EWL at 1-3 years after surgery (76% EWL at 1 year, 80% EWL at 2 years, and 75% EWL at 3 years).*
About Dr. Oliak
Our gastric sleeve program

Gastric Sleeve Surgeon Dr. Oliak’s Weight Loss Statistics*

61% EWL after 6 months

76% EWL after 1 year

80% EWL after 2 years

75% EWL after 3 years

Gastric Sleeve Surgeon Dr. Oliak’s Weight Loss Statistics Compared to Industry Averages

Time after surgery

Dr. Oliak’s %EWL*

Industry average %EWL*

1 year



2 years



3 years



* The weight loss results above are averages. Individual patients can lose more or less weight than the average.
Gastric sleeve surgeon Dr. Oliak’s %EWL (excess weight loss) statistics are for all gastric sleeve operations completed 2008-2017 (n=375). Industry average %EWL statistics are from a study by Gagner et al of 130 surgeons and 46,133 gastric sleeve operations.

What is excess weight?

Excess weight is the amount of weight over ideal weight. Ideal weight can be found in Metropolitan Life Insurance height-weight tables. Ideal weight is considered to be the middle weight in the medium frame size range. For example, ideal weight (not goal weight) for a 5’4″ woman is considered to be 134 pounds, and ideal weight (not goal weight) for a 5’11” man is considered to be 164 pounds.

Gastric Sleeve Outcomes – Complications

Sleeve gastrectomy has been proven to be a safe operation. As with all operations, however, complications can occur. The most important early complication is generally considered to be leak (discussed below), and the most important late complication is generally considered to be acid reflux (discussed below).

Gastric Sleeve Leak

A gastric sleeve leak is a hole in the stomach along the line of division that occurs early after surgery before complete healing has occurred. A gastric sleeve leak is a serious, potentially life-threatening complication that all sleeve gastrectomy surgeons try hard to prevent.

Published Studies

Published gastric sleeve outcomes studies show that gastric sleeve leak rates vary widely between surgeons, from 0-9%.** The best study reports 0 leaks in 529 patients, and the worst study reports 4 leaks in 45 patients. Clearly some surgeons are able to achieve much lower gastric sleeve leak rates than other surgeons.**
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Industry Average Leak Rate

Leak rates vary by surgeon from a low of 0% to a high of 9%, but what is the overall industry average for all sleeve gastrectomy surgeons? Aurora et al compiled leak data from 29 different studies with a total of 4,888 gastric sleeve operations, and found the overall gastric sleeve leak rate (industry average) to be 2.4% (1 in 40 operations).**

Dr. Oliak’s Gastric Sleeve Leak Statistics

Orange County sleeve gastrectomy surgeon Dr. Oliak’s leak rate is 0% (0 in 375 operations).** This ranks among the best reported leak statistics in the field, and is significantly lower than the industry average gastric sleeve leak rate of 2.4%.*
About Dr. Oliak
Our gastric sleeve program

Sleeve Gastrectomy Surgeon Dr. Oliak’s Leak Rate Compared to Industry Average

Outcome parameter

Dr. Oliak’s leak rate**

Industry average leak rate**

Leak rate

0% (0 in 375 operations)

2.4% (1 in 40 operations)

** Leaks can occur after gastric sleeve surgery. Past performance is not necessary indicative of future results. Orange County sleeve gastrectomy surgeon Dr. Oliak’s 0% leak rate statistic applies to all gastric sleeve operations (primary and revision) completed 2008-2017 (n=375). Industry average leak rate statistic from Aurora et al study which compiled leak data from 29 studies with a total of 4,888 gastric sleeve operations.

Acid Reflux after Gastric Sleeve

Acid reflux (gerd) is the main potential long-term complication after sleeve gastrectomy surgery. Minor or moderate acid reflux after gastric sleeve surgery can generally be successfully treated with antacid medications. More severe acid reflux may require an operation to address the cause (hiatal hernia, dilated upper sleeve), or to convert to a different operation, typically gastric bypass.

Published Studies

The published studies on acid reflux after gastric sleeve surgery report widely variable results. In general, studies show that there is a percentage of patients who develop new or worsened gerd symptoms after surgery. The percentage varies depending on the study from low to high.

Industry Average Acid Reflux Rates

What is the industry average percentage of patients who have new or worsened acid reflux after gastric sleeve surgery? Oor et al reviewed 33 studies on acid reflux after gastric sleeve, and concluded that it was not possible to determine the industry average acid reflux rate. Surgeon heterogeneity (differences in outcomes between surgeons) between the studies was so large that estimations of industry averages could not be made.

This finding of extreme surgeon heterogeneity reflects the lack of agreement on what specific surgical techniques are required to prevent acid reflux. Different surgeons have widely variable techniques, and these different techniques translate into widely variable long-term acid reflux rates.
Outcomes vary between surgeons

Dr. Oliak’s Acid Reflux Statistics

Of Dr. Oliak’s gastric sleeve patients over the last 3 years with at least 6 months of follow-up after surgery, new or worsened acid reflux occurred in 16% of patients.

The lowest rate of postoperative gerd (10%) occurred in patients with no preoperative gerd, and no hiatal hernia at the time of surgery. Patients with preoperative gerd and hiatal hernia had a 16% incidence of worsened postoperative gerd.

The highest rate of severe gerd (20%) occurred in patients with preoperative gerd and a large hiatal hernia. Based on these data and other published data, patients with chronic gerd and large hiatal hernias are probably better treated with gastric bypass rather than sleeve gastrectomy.*

Gastric Sleeve Improves Medical Conditions

Medical problems associated with weight, including diabetes, high blood pressure, hyperlipidemia, sleep apnea, joint pain, asthma, depression, infertility, urinary stress incontinence, lower extremity swelling, and headaches all tend to resolve or improve with weight loss after sleeve gastrectomy surgery.*

Weight Loss Surgery Patients Live Longer

Numerous published studies have shown that weight loss surgery patients live longer than similarly obese patients who don’t have surgery. This is because the surgery patients lose weight, become healthier, and suffer fewer heart attacks, fewer strokes, and less cancer (reference).*

  • 0%leak rate**
  • 76% excess weight loss 1 year*
  • 80% excess weight loss 3 years*

Gastric Sleeve before & after

See more
  • Alan
  • Procedure: Gastric Sleeve
  • Weight Lost: 115 lbs
  • Excess Weight Lost: 91%
  • Disclaimer: Individual results vary
My weight loss journey has completely changed my life. I feel so much better going out and spending time with…
Read More

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Learn more about sleeve gastrectomy and our program

Schedule a free, no-obligation consultation with Dr. Oliak in Orange County – Brea or Irvine – today!

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Call 714-582-2530 or submit the following information to request a free consult. If you have insurance coverage for weight loss surgery (or are self-pay), and you meet the BMI criteria for surgery, we will schedule you for a 30-40 minute educational consultation with Dr. Oliak.

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