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Home > CA Providers > Bariatric Surgeons

Dr. Thomas Jun Hirai, MD

Accepting New Patients

(9 Ratings)

Specializes in: Bariatric Surgery and General Surgery

University of São Paulo Faculty of Medicine

Professional interests include: minimally invasive surgery, robotic surgery, obesity, and more.

200 Jose Figueres Avenue Suite 450
San Jose, CA 95116

(408) 929-5610

Dr. Thomas Jun Hirai, MD is a bariatric surgeon in San Jose, CA specializing in bariatric surgery and general surgery. He graduated from University of São Paulo Faculty of Medicine. Dr. Thomas Jun Hirai, MD is affiliated with Good Samaritan Hospital, El Camino Health and Washington Hospital Healthcare System.

Office Locations

Good Samaritan Hospital

200 Jose Figueres Avenue Suite 450
San Jose, CA 95116

(669) 284-8181

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Some issues Dr. Thomas Jun Hirai, MD can help you with:

Gastric Bypass Surgery

Gastric bypass surgery is a procedure that promotes weight loss by reducing the stomach and altering how the digestive system absorbs and processes food. The procedure treats morbid obesity, where one's weight impairs day-to-day function or poses serious health risks. Gastric bypass surgery is used only after other weight loss treatments are unsuccessful.

Generally, gastric bypass surgery is performed on patients who have a BMI of 40 or greater, or a BMI of 35 or greater with a weight-related health condition such as type 2 diabetes. Bariatric surgeons frequently expect patients to first attempt natural weight loss for about six months to prove to the surgeon that the patient is capable of maintaining a post-surgery diet and exercise regimen.

For obese patients, gastric bypass surgery has many potential health and weight benefits. Gastric bypass surgery restricts the amount of food the stomach contains, as well as:

Reduces the calories the stomach absorbs
Alters gastrointestinal hormones, which help to heal obesity-induced metabolic syndrome
Suppresses appetite
Alleviates conditions caused or exacerbated by obesity, such as obstructive sleep apnea, heart disease, and type 2 diabetes
Contributes to mental health by improving self-esteem

During gastric bypass surgery, the stomach is stapled to reduce its size, and a small hole is created in the stomach and attached to the middle section of the small intestine. This direct connection between the stomach and the middle of the small intestine creates a channel for some food to bypass the normal route. By bypassing the upper small intestine and larger region of the stomach, food is not fully absorbed and patients do not retain the same amount of calories as before. This procedure is also sometimes referred to as "Roux-en-Y" gastric bypass surgery. Some bariatric surgeons may perform a "laparoscopic bypass" which uses a tiny camera (laparoscope) to guide the procedure.

Gastric bypass surgery is performed with general anesthesia and as preparation, a liquid diet is required for two weeks prior to undergoing the surgery. After the surgery, patients will spend about two days in the hospital and may miss work for two to three weeks. In the first month after the surgery, patients are only able to consume small portions of liquid or soft food. Even after reintroducing solid food, patients feel full quickly, sometimes after eating just two or three tablespoons. Some patients experience "dumping syndrome" (rapid processing of food into the small intestine), which is common during the recovery process. Gastric bypass surgery patients must also make permanent lifestyle changes. For example, gastric bypass patients are required to take vitamins for life after surgery and required to forever avoid certain foods, such as alcohol, sugar, and high fat food.

While the gastric bypass recovery process can be challenging, surgery results are usually swift: most gastric bypass surgery patients lose nearly half to two thirds of their starting weight within two years of surgery.

Robotic Surgery

Robotic surgery is a type of minimally invasive surgery, using a tiny opening to get inside the body instead of making a large cut. It uses small tools attached to a thin robotic arm, which is controlled by the surgeon. Robotic surgery may be referred to by the specific kind of robot that is used. The most advanced robot currently in use is called the da Vinci, and surgery using it is sometimes called da Vinci surgery.

There are many benefits to robotic surgery, both for the patient and the surgeon. Robotic surgery allows for more precise movements and increased control during very delicate surgical procedures. This makes performing surgery accurately much easier for surgeons and reduces fatigue. The smaller 'hand' of the robot can enter the body via a much smaller opening, which reduces the risk of infection and scarring and leads to a faster recovery. The robotic hands also contain tiny moveable cameras among their tools, giving surgeons a much closer view of the procedure than would be possible with traditional surgery.

Weight Loss Surgery (Bariatric Surgery)

Bariatric or weight-loss surgery is a surgical procedure performed to help significantly obese patients lose weight when more traditional methods, such as dieting and exercise, have not helped. Depending on the type, these surgeries change the gastrointestinal tract to limit how much food can be eaten and also change how food is absorbed by the body. Of the various bariatric surgeries available, the most common is gastric bypass.

By far the most common of the gastric bypass surgeries is called Roux-en-Y. During this surgery, part of the stomach and small intestine are detached from the gastrointestinal tract, in order to make the tract smaller. The surgeon divides the stomach into two parts. The working stomach, at the end of the esophagus, is now tiny - only the size of a walnut. This makes patients feel full after eating a small amount of food. Then the small intestine is also divided, and after bypassing a section of the small intestine to reduce food absorption, the intestine is attached to the small stomach pouch. The patient now has a working stomach and intestine like before, only much smaller.

Because gastric bypass is used to treat extreme obesity, it can reduce the risk of some of the problems associated with obesity. Gastric bypass can help treat or reduce the risk for such conditions as heart disease, high blood pressure, sleep apnea, and type 2 diabetes. However, it is a major surgery and also carries risks itself. Any surgery can lead to infection, bleeding, or blood clots, and weight loss surgery in particular carries risks of leaks in the gastrointestinal system, malnutrition, bowel obstructions, and vomiting.

Typically patients are considered candidates for gastric bypass surgery if they have a BMI greater than 40, or sometimes if they have a BMI between 35 and 40 but are suffering from obesity-related illnesses such as diabetes. The outlook is generally good, with most patients losing between 50-75% of their excess weight in 1-2 years. However, patients must follow strict diet guidelines so that the stomach can heal, starting with no food at all, then followed by a liquid diet for some time. For many severely obese patients who have tried strict diets before without success, gastric bypass surgery is the tool that allows them to finally achieve their weight loss and health goals.

Medicare Procedure and Patient Information

2012 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2012 were hospital care and inpatient care.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

hospital care	171
inpatient care	171

Medicare Procedure and Patient Information

2013 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2013 were hospital care, inpatient care, anastomosis and minimally invasive procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

anastomosis	27
catheterization	27
doctor visit	76
gastrointestinal procedures	27
hospital care	214
inpatient care	214
minimally invasive procedures	27
tracheal (windpipe) procedures	14

2013 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	117
Female	138

**Ethnicity**
Non-Hispanic White	70
Black	0
Hispanic	84
Asian	89
Other	0
Native American	0

**Age**
From 65 to 74	74
From 75 to 84	69
85 and over	37
Less than 65	75

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2013

Hypertension	75
High Cholesterol	68
Stroke	11
Ischemic Heart Disease	47
Depression	27
Chronic Kidney Disease	43
Asthma	19
Osteoperosis	11
Atrial Fibrilation	15
Heart Failure	35
Chronic Obstructive Pulmonary Disease	25
Diabetes	62
Dementia	22
Cancer	14

Medicare Procedure and Patient Information

2014 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2014 were hospital care, inpatient care, anastomosis and minimally invasive procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

anastomosis	52
catheterization	52
doctor visit	106
gastrointestinal procedures	52
hospital care	229
inpatient care	229
minimally invasive procedures	52
tracheal (windpipe) procedures	17

2014 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	142
Female	150

**Ethnicity**
Non-Hispanic White	73
Black	0
Hispanic	104
Asian	101
Other	0
Native American	0

**Age**
From 65 to 74	86
From 75 to 84	86
85 and over	56
Less than 65	64

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2014

Hypertension	75
High Cholesterol	73
Stroke	16
Ischemic Heart Disease	46
Depression	19
Chronic Kidney Disease	43
Asthma	14
Osteoperosis	11
Atrial Fibrilation	15
Heart Failure	32
Chronic Obstructive Pulmonary Disease	19
Diabetes	63
Dementia	29
Cancer	12

Medicare Procedure and Patient Information

2015 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2015 were hospital care, inpatient care, anastomosis and minimally invasive procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

anastomosis	24
catheterization	24
doctor visit	55
gastrointestinal procedures	24
hospital care	227
inpatient care	227
minimally invasive procedures	24

2015 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	184
Female	184

**Ethnicity**
Non-Hispanic White	0
Black	0
Hispanic	126
Asian	132
Other	0
Native American	0

**Age**
From 65 to 74	116
From 75 to 84	96
85 and over	64
Less than 65	92

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2015

Hypertension	75
High Cholesterol	69
Stroke	17
Ischemic Heart Disease	47
Depression	26
Chronic Kidney Disease	52
Asthma	19
Osteoperosis	11
Atrial Fibrilation	19
Heart Failure	33
Chronic Obstructive Pulmonary Disease	20
Diabetes	55
Dementia	24
Cancer	9

Medicare Procedure and Patient Information

2016 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2016 were hospital care, inpatient care, anastomosis and minimally invasive procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

anastomosis	27
catheterization	27
doctor visit	75
gastrointestinal procedures	27
hospital care	108
inpatient care	108
minimally invasive procedures	27
tracheal (windpipe) procedures	15

2016 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	64
Female	79

**Ethnicity**
Non-Hispanic White	0
Black	0
Hispanic	49
Asian	54
Other	0
Native American	0

**Age**
From 65 to 74	44
From 75 to 84	47
85 and over	24
Less than 65	28

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2016

Hypertension	75
High Cholesterol	72
Stroke	15
Ischemic Heart Disease	46
Depression	20
Chronic Kidney Disease	58
Asthma	22
Osteoperosis	10
Atrial Fibrilation	19
Heart Failure	34
Chronic Obstructive Pulmonary Disease	20
Diabetes	56
Dementia	23
Cancer	17

Medicare Procedure and Patient Information

2017 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2017 were hospital care, inpatient care, anastomosis and minimally invasive procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

anastomosis	11
catheterization	11
doctor visit	67
gastrointestinal procedures	11
hospital care	138
inpatient care	138
minimally invasive procedures	11

2017 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	56
Female	84

**Ethnicity**
Non-Hispanic White	0
Black	0
Hispanic	45
Asian	54
Other	0
Native American	0

**Age**
From 65 to 74	50
From 75 to 84	40
85 and over	29
Less than 65	21

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2017

Hypertension	75
High Cholesterol	69
Stroke	12
Ischemic Heart Disease	49
Depression	19
Chronic Kidney Disease	54
Asthma	12
Osteoperosis	10
Atrial Fibrilation	18
Heart Failure	31
Chronic Obstructive Pulmonary Disease	17
Diabetes	53
Dementia	26
Cancer	14

Medicare Procedure and Patient Information

2018 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2018 were hospital care, inpatient care, anastomosis and minimally invasive procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

anastomosis	13
catheterization	13
doctor visit	135
gastrointestinal procedures	13
hospital care	104
inpatient care	104
minimally invasive procedures	13

2018 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	81
Female	93

**Ethnicity**
Non-Hispanic White	34
Black	0
Hispanic	59
Asian	56
Other	0
Native American	0

**Age**
From 65 to 74	66
From 75 to 84	51
85 and over	25
Less than 65	32

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2018

Hypertension	75
High Cholesterol	75
Stroke	7
Ischemic Heart Disease	48
Depression	23
Chronic Kidney Disease	50
Asthma	13
Osteoperosis	13
Atrial Fibrilation	15
Heart Failure	30
Chronic Obstructive Pulmonary Disease	14
Diabetes	56
Dementia	21
Cancer	20

Medicare Procedure and Patient Information

2019 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2019 were hospital care and inpatient care.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

doctor visit	142
hospital care	17
inpatient care	17

2019 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	57
Female	71

**Ethnicity**
Non-Hispanic White	24
Black	0
Hispanic	42
Asian	50
Other	0
Native American	0

**Age**
From 65 to 74	47
From 75 to 84	55
85 and over	0
Less than 65	0

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2019

Hypertension	75
High Cholesterol	75
Stroke	9
Ischemic Heart Disease	52
Depression	19
Chronic Kidney Disease	52
Asthma	14
Osteoperosis	11
Atrial Fibrilation	12
Heart Failure	29
Chronic Obstructive Pulmonary Disease	16
Diabetes	55
Dementia	14
Cancer	21

Medicare Procedure and Patient Information

2020 Medicare Procedure Volume

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

doctor visit	175

2020 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	56
Female	72

**Ethnicity**
Non-Hispanic White	27
Black	0
Hispanic	40
Asian	49
Other	0
Native American	0

**Age**
From 65 to 74	59
From 75 to 84	40
85 and over	14
Less than 65	15

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2020

Hypertension	75
High Cholesterol	71
Stroke	0
Ischemic Heart Disease	42
Depression	20
Chronic Kidney Disease	47
Asthma	0
Osteoperosis	9
Atrial Fibrilation	13
Heart Failure	28
Chronic Obstructive Pulmonary Disease	9
Diabetes	52
Dementia	11
Cancer	20

Medicare Procedure and Patient Information

2021 Medicare Procedure Volume

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

doctor visit	181

2021 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	64
Female	72

**Ethnicity**
Non-Hispanic White	0
Black	0
Hispanic	43
Asian	53
Other	0
Native American	0

**Age**
From 65 to 74	48
From 75 to 84	50
85 and over	20
Less than 65	18

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2021

Hypertension	75
High Cholesterol	75
Stroke	10
Ischemic Heart Disease	47
Depression	21
Chronic Kidney Disease	59
Asthma	0
Osteoperosis	11
Atrial Fibrilation	10
Heart Failure	26
Chronic Obstructive Pulmonary Disease	9
Diabetes	55
Dementia	21
Cancer	18

Medicare Procedure and Patient Information

2022 Medicare Procedure Volume

The top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA during 2022 were minimally invasive procedures, abdominal surgery and gastrointestinal procedures.

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

abdominal surgery	12
doctor visit	132
gastrointestinal procedures	12
minimally invasive procedures	12

2022 Medicare Patient Data

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Male	53
Female	56

**Ethnicity**
Non-Hispanic White	40
Black	0
Hispanic	0
Asian	35
Other	0
Native American	0

**Age**
From 65 to 74	47
From 75 to 84	28
85 and over	17
Less than 65	17

Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD in 2022

Hypertension	75
High Cholesterol	75
Stroke	0
Ischemic Heart Disease	32
Depression	14
Chronic Kidney Disease	36
Asthma	10
Osteoperosis	16
Atrial Fibrilation	0
Heart Failure	22
Chronic Obstructive Pulmonary Disease	0
Diabetes	48
Dementia	15
Cancer	20

Medicare Procedure and Patient Information

Average Medicare Procedure Volume From 2012 - 2022

Volume of procedures performed by Dr. Thomas Jun Hirai, MD for Medicare patients.

The highest averages for the top procedures that Dr. Thomas Jun Hirai, MD treated as a bariatric surgeon in San Jose, CA were hospital care, inpatient care, anastomosis and catheterization.

abdominal surgery	12
anastomosis	25
catheterization	25
doctor visit	114
gastrointestinal procedures	23
hospital care	151
inpatient care	151
minimally invasive procedures	23
tracheal (windpipe) procedures	15

Average Medicare Patient Data From 2012 - 2022

Information about Medicare patients treated by Dr. Thomas Jun Hirai, MD.

**Gender**
Female	90
Male	79

**Ethnicity**
Black / African American	0
Asian / Pacific Islander	61
Non-Hispanic White	24
Native American / Alaskan Native	0
Hispanic	53
Other	0

**Age**
85 and over	26
75 to 84	51
Less than 65	32
65 to 74	57

Average of Total of Conditions of Medicare patients treated by Dr. Thomas Jun Hirai, MD From 2012 - 2022

The highest averages of the most common conditions of Medicare patients that Dr. Thomas Jun Hirai, MD treated were hypertension, high cholesterol, diabetes and chronic kidney disease.

Hypertension	68
High Cholesterol	65
Stroke	8
Ischemic Heart Disease	41
Depression	18
Chronic Kidney Disease	44
Asthma	11
Osteoporosis	10
Heart Failure	27
Chronic Obstructive Pulmonary Disease	13
Diabetes	50
Atrial Fibrillation	12
Dementia	18
Cancer	15

Education & Training

Dr. Thomas Jun Hirai, MD graduated from University of São Paulo Faculty of Medicine. He completed residency at New York Medical College Affiliated Hospitals. He is certified by the American Board of Surgery, Surgery (General Surgery) and has a state license in California.

Medical School: University of São Paulo Faculty of Medicine

Residency: New York Medical College Affiliated Hospitals (2005)

Board Certification: American Board of Surgery, Surgery (General Surgery)

Licensed In: California

Affiliations & Hospitals

Dr. Thomas Jun Hirai, MD is associated with these hospitals and organizations:

Good Samaritan Hospital

El Camino Health

Washington Hospital Healthcare System

Insurance Information

Please note: Insurance information may change at any time, and the provider may accept your insurance plan even if it is not listed below. Please contact the provider's office to confirm that your insurance is accepted.

Dr. Thomas Jun Hirai, MD appears to accept the following insurance providers: United Healthcare PPO.

Insurance Accepted by Provider includes:

According to our sources, Dr. Thomas Jun Hirai, MD accepts the following insurance providers:

United Healthcare PPO

Ratings & Reviews

Dr. Thomas Jun Hirai, MD has an exceptional overall rating with an average of 4.56 out of 5 stars based on 9 ratings. We collect ratings and reviews of Dr. Thomas Jun Hirai, MD from all over the web to help you find the right in San Jose, CA.

4.56

Overall Rating

(9 Ratings)

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General Payments

These charts describe general payments received by Dr. Thomas Jun Hirai, MD. Doctors may receive payments for a number of reasons, including meal compensation, travel compensation, and consulting.

**Payments by Company**
Intuitive Surgical, Inc.	$25,760 Da Vinci Surgical System $21,760	DAVINCI XI $4,000
Ethicon Inc.	$17,538 Monarch Platform $12,492	Monarch $4,986	DERMABOND PRINEO $37	$24
Auris Health, Inc.	$5,568 Monarch $5,550	$18
Davol Inc.	$4,585 PHASIX $2,019	DAV-Phasix $1,392	SURGICAL $802	DAV-XenMatrix AB $349	DAV-VENTRALIGHT $24
W. L. Gore & Associates, Inc.	$2,103 BIO-A Tissue Reinforcement $992	GORE SEAMGUARD Bioabsorbable Staple Line Reinforce $817	BIO A Tissue Reinforcement $188	SEAMGUARD Staple Line Reinforce $72	SEAMGUARD Staple Line Reinforcement $34
Other	$8,111 DERMACELL $2,036	Pacemakers $1,695	AirSeal $482	ECHELON ENDOPATH Stapler $425	EVEREST $316	Other $3,157

**Types of Payments**
Consulting Fee	$21,934
Education	$15,571
Travel and Lodging	$14,359
Food and Beverage	$11,177
Compensation for services other than consulting, including serving as faculty or as a speaker at a venue other than a continuing education program	$300
Other	$324

Biography

Dr. Thomas Hirai specializes in general surgery and bariatric surgery and practices in San Jose, CA. His areas of expertise include laparoscopic sleeve gastrectomy, duodenal switch, and roux-en-y gastric bypass. His patients gave him an average rating of 4.5 stars (out of 5). Dr. Hirai seems to honor United Healthcare PPO and United Healthcare insurance. Before performing his residency at a hospital affiliated with New York Medical College, Dr. Hirai attended the University of São Paulo Faculty of Medicine for medical school. Dr. Hirai (or staff) speaks the following foreign languages: Spanish, Japanese, and Portuguese. His hospital/clinic affiliations include Washington Hospital Healthcare System, Good Samaritan Hospital, and El Camino Health. He has an open panel in San Jose, CA according to El Camino Health.