Thoraflex™ Hybrid IDE Study

Vascutek Ltd has developed the Thoraflex™ Hybrid Device (Plexus™ 4 and Ante-Flo™) for the
open surgical repair or replacement of damaged or diseased vessels of the aortic arch and
descending aorta, with or without involvement of the ascending aorta, in cases of aneurysm
and/or dissection. The Thoraflex™ Hybrid Device may be considered a development of the
Elephant Trunk (ET) grafts with the addition of a stented distal section. In some cases this
will allow for a single stage procedure to be carried out, dependent on the length of
affected vessel. As the device is fully sealed and has a collar to aid anastomosis, it
removes the requirement for in situ sealing and the suturing together of two devices, thereby
reducing cardiopulmonary bypass (CPB) time and overall procedure time.

By reducing the procedure time and negating the need for as many subsequent procedures, this
method could greatly improve the success of this procedure and may improve patient outcomes.

The ability to treat complex anatomies in addition to reducing procedure and CPB time,
justify the investigation of the Thoraflex™ Hybrid Device. Safety and effectiveness data for
subjects treated with the Thoraflex™ Hybrid Device will be compared to historical data from
subjects treated using standard ET surgical repair.

It is anticipated that up to 83 patients will be recruited over a 14 month period
(approximately). Patients will be evaluated at the following time points: Pre-procedure,
Implant, Discharge/30 days, 3 months, 12 months, 24 months and 36 months. An additional visit
may be performed for patients who undergo an extension procedure within 1 year of Thoraflex™
Hybrid Device implantation.

65 patients will be recruited to the primary study group (maximum 19 per site). An additional
group of patients with a ruptured aorta may also be recruited (up to approximately 18
patients across all sites).

A historical control population has been derived from a comparable patient population who
received treatment for thoracic aortic disease using the current standard of care, which is
the conventional (2-stage) elephant trunk technique. Using data from the comparator
population a Performance Goal Target has been set at 57.4%.

The study will be deemed a success if the lower limit of the 95% confidence interval,
associated with the proportion of study patients who are free from the defined composite
Major Adverse Events (permanent stroke, permanent paraplegia/paraparesis, unanticipated
aortic related re-operation and all-cause mortality) at 1 year post procedure, is greater
than 57.4%. Only patients included in the main study group will be included in the
Performance Goal Analysis; patients recruited into the additional Aortic Rupture group will
not be included in the primary endpoint analysis. All patients in the main study group will
be included in the analysis regardless of whether or not an extension procedure has been
performed.

Inclusion Criteria:

Main Study Group (All patients except Aortic Rupture Patients)

- Patient is aged 18 years or over on date of consent

- Patient is willing and able to comply with all study procedures and study visits

- Patient or their legally authorized representative has given written informed consent
to participate in study

- Patient satisfies the inclusion criteria for one of the following categories:

A - Patient has acute dissection of the aorta or B - Patient has chronic dissection of the
aorta or C - Patient has an aortic aneurysm (including connective tissue disorders)

A. - Patients with acute dissection of the aorta:

•Patient has acute aortic dissection and requires repair or replacement of damaged or
diseased vessels of the aortic arch (with or without involvement of the ascending aorta),
and the descending aorta requires replacement, or, in the opinion of the investigator, the
patient would derive clinical benefit from prophylactic treatment of the descending aorta.

B. - Patients with chronic dissection of the aorta:

•Patient requires repair or replacement of damaged or diseased vessels of the aortic arch
and descending aorta with or without involvement of the ascending aorta due to chronic
dissection.

And patient satisfies one or more of the following criteria:

- Patient has aortic sinus, or ascending aorta, or aortic arch, or descending aorta
diameter ≥5.5cm (including if asymptomatic) or

- Patient has aorta diameter <5.5cm and growth rate ≥0.5cm/year (including if
asymptomatic) or

- Patient has ascending aorta diameter ≥4.5cm and requires valve repair or replacement

C. - Patients with an aortic aneurysm (including connective tissue disorders):

•Patient requires repair or replacement of damaged or diseased vessels of the aortic arch
and descending aorta with or without involvement of the ascending aorta

And patient satisfies one or more of the following criteria:

- Patient has aortic sinus, or ascending aorta, or aortic arch, or descending aorta
diameter ≥5.5cm (including if asymptomatic) or

- Patient has aorta diameter <5.5cm and growth rate ≥0.5cm/year(including if
asymptomatic) or

- Patient has ascending aorta diameter ≥4.5cm and requires valve repair or replacement
or

- Patient has Marfan syndrome or other genetically mediated disorders with aortic sinus,
or ascending aorta, or arch diameter ≥4.5cm, or, the ratio of the maximal ascending or
aortic root area (Π r2) in cm2 divided by the patient's height in meters exceeds 10

Inclusion criteria for Patients with Ruptured Aorta only:

- Patient is aged 18 years or over, on date of consent

- Patient or their legally authorized representative is able and willing to give consent
to the patient's enrolment in the study

- Patient has either a ruptured thoracic aorta, or, in the experience of the treating
surgeon, is at high risk of imminent rupture of the thoracic aorta

Exclusion Criteria:

Main Study Group (All Patients Except Patients with Ruptured Aorta)

- Patient is unfit for open surgical repair involving circulatory arrest

- Patient has known sensitivity to polyester, nitinol or materials of bovine origin

- Patient has a ruptured aorta

- Patient has active endocarditis or an active infective disorder of the aorta

- Patient has an active systemic infection that, in the opinion of the investigator,
would compromise the outcome of the surgical procedure

- Patient is enrolled in another active study and has received an investigational
product (device, pharmaceutical or biologic) within 6 months prior to the date of the
implant or has not reached the primary endpoint of the study

- Patient is female and is pregnant, or planning to become pregnant during the course of
the study. Females of childbearing potential must use acceptable methods of
contraception.

- Patient has an uncorrectable bleeding anomaly

- Patient has renal failure (defined as dialysis dependent or serum creatinine
≥2.5mg/dL)

- Patient has known sensitivity to radiopaque contrast agents that cannot be adequately
pre-treated

- Patient has a co-morbidity causing expected survival to be less than 1 year

- Patient has any other medical, social or psychological problems that in the opinion of
the investigator preclude them from receiving this treatment and the procedures and
evaluations pre and post procedure

Exclusion criteria for Patients with Ruptured Aorta only:

- Patient has chronic dissection which, in the opinion of the investigator, can be
treated electively

- Patient has aneurysmal disease which, in the opinion of the investigator, can be
treated electively