Dr. Mark Brennan, DO


General Surgery | Male

United Health Services 30 Harrison St Ste 455 Johnson City, NY 13790 Get Directions
Dr. Mark Brennan, DO
Dr. Mark Brennan, DO is a general surgery doctor who practices in Johnson City, NY. He is 51 years old and has been practicing for 23 years. Dr. Brennan is affiliated with UHS - Binghamton General Hospital.

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Dr. Brennan's Experience

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Conditions Treated

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Procedures Performed

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Background Check

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Languages Spoken

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Memberships & Professional Affiliations

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Visiting Dr. Brennan

Dr. Brennan accepts 9 insurance carriers

Dr. Brennan is now accepting new patients

Affiliated Hospitals

Hospital Quality
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Dr. Brennan's Reviews

Likelihood of recommending Dr. Brennan to family and friends
based on 18 total reviews (6 with comments)
Dr. Brennan's Performance
  • Trustworthiness
  • Explains condition(s) well
  • Answers Questions
  • Time well spent
Office & Staff Performance
  • Scheduling
  • Office environment
  • Staff friendliness
  • Average wait time
    10 to 15 minutes
Patient Comments (6)
in Binghamton, NY |
I, myself, looked through Dr. Brennan's reviews to see if others recommended him as well before my surgery so I decided to write my own review. Dr. Brennan performed a scheduled cholecystectomy (gall bladder removal) for me and it could not have gone any better! I was so nervous/scared/anxious as this was my first surgery ever and I am only 19.. but he reassured me he would do his absolute best and I was in safe hands. He did an amazing job with a very quick recovery! He did not let me down!
Binghamton, NY |
Horrible. Don't go to him!! Did a junk by-pass with artificial vein which caused massive infection. Then gave up on the leg. Didn't care. Leg saved by another surgeon, not UHS based!
in Whitney Point, NY |
Over the Christmas holidays my husband became ill with what we thought were heart issues.Fortunetly this wasn't the case. It was gallbladder problems. Dr. Brennan didn't hesitate and insisted the surgery be done on Christmas Day. His bedside manner was personable and his surgical skill enabled my husband to be back home in a matter of two days. I would highly recommend this fine man and I sincerely thank him for his care of my husband.
in Newark Valley, NY |
Dr. Brennan is compassionate, courteous and able to answer all my questions and concerns. I am glad he was the surgeon chosen by my team of doctors. Thank you, Dr. Brennan and The Lord Bless you. I am unable to answer three of four questions in the first part below as I was treated by Dr. Brennan while in hospital. I dealt with his staff on the phone after my chemo treatments were done.
in Endicott, NY |
Doctor Brennan is a wonderful and caring doctor. He saved my dad's life on October 10, 2015. My dad was rushed to surgery for an emergency abdominal aortic aneurysm. His aneurysm was beyond the point of a minor repair and we were told the risk of him NOT surviving was great. While in surgery the aneurysm ruptured but Dr. Brennan was able to save his life. I cannot praise Dr. Brennan enough for all he did for us, his knowledge, wonderful bedside manner and overall treatment he gave to my dad. He
in Johnson city,ny |
He acted like I wasn't really in pain.treated me as if i didndidn't know what I was talking about.after surgery he was an ass.yeah he gave me something for pain.but a few days later when he said i could double up on what he gave me for pain..then two days or so after surgery I was on my own.he doesnt want to help.so I'm left having to get out of pain on my own.so thanks a lot Dr Brennan hope you enjoy getting drunk in your off time.I'll be waiting to call the cops and happily be sure u get a dwi
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Dr. Brennan's experience matches your search based on the following criteria:

  •  Based on total number of patients treated over the last 12 months
  •  Specializes in General Surgery
  •  Board certified in General Surgery and General Vascular Surgery
  •  No malpractice claims found
  •  Sanctions found
  •  Board actions found

Background Check

  • 0
    Malpractice Claims

    No malpractice history found for New York.

    What is medical malpractice
  • 1

    Dr. Brennan has received 1 sanction

    What is a sanction or disciplinary action
    • Substandard Care, Incompetence or Negligence (12/11/2013)
    • Action Taken: Probation
    • Summary: Please reference the following Document
    • Documentation: Download here (PDF)
    • State: New York
  • 1
    Board Action

    Dr. Brennan has 1 board action

    What are board actions
    • Modification Order (10/1/2015)
    • Action Taken: Probation Terminated (Ended)
    • Summary: Please reference the following Document
    • Documentation: Download here (PDF)
    • State: New York

Board Certifications

Why It Matters: Dr. Brennan's Board Certifications

Board certification should be one of your top considerations when choosing a doctor. Board certification is an official recognition given to doctors who have met specific requirements set by national medical specialty boards in the... More

  • General Surgery
  • General Vascular Surgery

Conditions Treated

  • Abdominal Aortic Aneurysm (AAA)
  • Acute Deep Vein Thrombosis (DVT)
  • Acute Venous Embolism Thrombosis
  • Aneurysm
  • Aortic Aneurysm
  • Aortic Dissection
  • Aortic Ectasia
  • Aortic Embolism and Thrombosis
  • Atherosclerosis
  • Atherosclerosis of Aorta
  • Brachial Plexus Palsy
  • Carotid Artery Disease
  • Chronic Deep Vein Thrombosis (DVT)
  • Chronic Venous Embolism Thrombosis
  • Congenital Heart Defects
  • Deep Vein Thrombosis (DVT)
  • Heart Disease
  • Hypertensive Encephalopathy
  • Median Arcuate Ligament Syndrome (MALS)
  • Peripheral Arterial Aneurysm
  • Peripheral Arterial Aneurysm and Dissection
  • Peripheral Arterial Disease of Extremities
  • Peripheral Arterial Dissection
  • Peripheral Arterial Embolism and Thrombosis
  • Peripheral Autonomic Neuropathy
  • Peripheral Nerve Disorders
  • Peripheral Vascular Disease (PAD, PVD)
  • Phlebitis and Thrombophlebitis
  • Renal Artery Arteriosclerotic Disease
  • Ruptured Aortic Aneurysm
  • Secondary Hypertension
  • Thoracoabdominal Aortic Aneurysm
  • Thrombosis
  • Transient Ischemic Attack (TIA)
  • Varicose Veins
  • Vascular Disease
  • Venous Compression
  • Venous Embolism and Thrombosis
  • Venous Insufficiency


  • Medical School
    Philadelphia Coll Of Osteo Med

    Graduated in 1994

Languages Spoken

  • English

Memberships &
Professional Affiliations

Dr. Brennan does not have any memberships or affiliations listed. If you are Dr. Brennan and would like to add memberships or affiliations, please update your free profile.


  • General Surgery
  • Vascular Surgery

Procedures Performed

  • Aortic Repair, Open or Repair of Arterial Aneurysm, Open
  • Arteriovenous Fistula Repair
  • Arteriovenous Shunt Creation
  • Carotid Artery Stent Placement
  • Carotid Endarterectomy (CEA) or Excision of Infected Graft
  • Carotid Ultrasound
  • Dialysis Access Procedures
  • Dressing and-or Debridement of Wound, Infection, or Burn (incl. Negative Pressure Wound Therapy)
  • Embolectomy, Thrombectomy, or Vessel Exploration
  • Endovascular Repair of Abdominal Aortic Aneurysm
  • Endovascular Repair of Aorta
  • Heart Surgery
  • Laparotomy
  • Lung Surgery
  • Non-Coronary Angioplasty, Atherectomy, and Stenting
  • Peripheral Artery Bypass
  • Peripheral Artery Catheterization
  • Port Placements or Replacements
  • Removal of Arteriovenous Shunt for Renal Dialysis
  • Revision of Arteriovenous Shunt for Renal Dialysis
  • Thromboendarterectomy or Excision of Infected Graft
  • Varicose Vein Procedure
  • Vascular Duplex Ultrasonography and Plethysmography
  • Vascular Surgical Procedure