TriVascular (TRIV) SC 13G TriVascular Technologies, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13G

UNDERTHE SECURITIES EXCHANGE ACTOF 1934

(Amendment No.     )*

Trivascular Technologies, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

89685A102

(CUSIP Number)

December 31, 2014

(Date of Event Which Requires Filing of This Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨  Rule 13d-1(b)

¨  Rule 13d-1(c)

x Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 89685A102

1.	Name of Reporting Persons MPM BioVentures IV-QP, L.P.
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 1,700,218*
		6.	Shared Voting Power 0
		7.	Sole Dispositive Power 1,700,218*
		8.	Shared Dispositive Power 0
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,700,218*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.3%
12.	Type of Reporting Person (See Instructions) PN

* Includes 35,025 shares of Common Stock issuable pursuant to warrants, which are exercisable within 60 days of the date of this filing.

Page 2 of 16

CUSIP No. 89685A102

1.	Name of Reporting Persons MPM BioVentures IV GmbH & Co. Beteiligungs KG
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization Germany
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 65,500*
		6.	Shared Voting Power 0
		7.	Sole Dispositive Power 65,500*
		8.	Shared Dispositive Power 0
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 65,500*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 0.3%
12.	Type of Reporting Person (See Instructions) PN

* Includes 1,349 shares of Common Stock issuable pursuant to warrants, which are exercisable within 60 days of the date of this filing.

Page 3 of 16

CUSIP No. 89685A102

1.	Name of Reporting Persons MPM Asset Management Investors BV4 LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 48,343*
		6.	Shared Voting Power 0
		7.	Sole Dispositive Power 48,343*
		8.	Shared Dispositive Power 0
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 48,343*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 0.2%
12.	Type of Reporting Person (See Instructions) OO

* Includes 995 shares of Common Stock issuable pursuant to warrants, which are exercisable within 60 days of the date of this filing.

Page 4 of 16

CUSIP No. 89685A102

1.	Name of Reporting Persons MPM BioVentures IV GP LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,765,718*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,765,718*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,765,718*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.6%
12.	Type of Reporting Person (See Instructions) PN

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by MPM BioVentures IV-QP, L.P. (“BV IV QP”) and 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held MPM BioVentures IV GmbH & Co. Beteiligungs KG (“BV KG”). The warrants listed above are exercisable within 60 days of the date of this filing. The Reporting Person is the direct general partner of BV IV QP and BV KG.

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CUSIP No. 89685A102

1.	Name of Reporting Persons MPM BioVentures IV LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,814,061*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,814,061*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,814,061*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.9%
12.	Type of Reporting Person (See Instructions) OO

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by MPM Asset Management Investors BV4 LLC (“AM BV4”). The warrants listed above are exercisable within 60 days of the date of this filing. The Reporting Person is the indirect general partner of BV IV QP and BV KG and the manager of AM BV4.

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CUSIP No. 89685A102

1.	Name of Reporting Persons Luke Evnin
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,814,061*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,814,061*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,814,061*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.9%
12.	Type of Reporting Person (See Instructions) IN

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and, 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. MPM BioVentures IV GP LLC (“MPM IV GP”) and MPM BioVentures IV LLC (“MPM IV LLC”) are the direct and indirect general partners of BV IV QP and BV KG and MPM IV LLC is the manager of AM BV4. The Reporting Person is a member of MPM IV LLC.

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CUSIP No. 89685A102

1.	Name of Reporting Persons Ansbert Gadicke
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,814,061*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,814,061*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,814,061*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.9%
12.	Type of Reporting Person (See Instructions) IN

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and, 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. MPM IV GP and MPM IV LLC are the direct and indirect general partners of BV IV QP and BV KG and MPM IV LLC is the manager of AM BV4. The Reporting Person is a member of MPM IV LLC.

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CUSIP No. 89685A102

1.	Name of Reporting Persons Vaughn M. Kailian
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,814,061*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,814,061*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,814,061*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.9%
12.	Type of Reporting Person (See Instructions) IN

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and, 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. MPM IV GP and MPM IV LLC are the direct and indirect general partners of BV IV QP and BV KG and MPM IV LLC is the manager of AM BV4. The Reporting Person is a member of MPM IV LLC.

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CUSIP No. 89685A102

1.	Name of Reporting Persons James Paul Scopa
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,814,061*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,814,061*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,814,061*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.9%
12.	Type of Reporting Person (See Instructions) IN

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and, 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. MPM IV GP and MPM IV LLC are the direct and indirect general partners of BV IV QP and BV KG and MPM IV LLC is the manager of AM BV4. The Reporting Person is a member of MPM IV LLC.

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CUSIP No. 89685A102

1.	Name of Reporting Persons Todd Foley
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  ¨        (b)  x
3.	SEC USE ONLY
4.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		5.	Sole Voting Power 0
		6.	Shared Voting Power 1,814,061*
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 1,814,061*
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,814,061*
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)   ¨
11.	Percent of Class Represented by Amount in Row (9) 8.9%
12.	Type of Reporting Person (See Instructions) IN

* Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and, 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. MPM IV GP and MPM IV LLC are the direct and indirect general partners of BV IV QP and BV KG and MPM IV LLC is the manager of AM BV4. The Reporting Person is a member of MPM IV LLC.

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Item 1.

(a) Name of Issuer

Trivascular Technologies, Inc.

(b) Address of Issuer’s Principal Executive Offices

3910 Brickway Boulevard

Santa Rosa, CA 95403

(c) Name of Person Filing

MPM BioVentures IV-QP, L.P.

MPM BioVentures IV GmbH & Co. Beteiligungs KG

MPM Asset Management Investors BV4 LLC

MPM BioVentures IV GP LLC

MPM BioVentures IV LLC

Luke Evnin

Ansbert Gadicke

Vaughn M. Kailian

James Paul Scopa

Todd Foley

(d) Address of Principal Business Office or, if none, Residence

c/o MPM Capital LLC

The John Hancock Tower

200 Clarendon Street, 54^th Floor

Boston, MA 02116

(e) Citizenship

All entities were organized in Delaware except MPM BioVentures IV GmbH & Co. Beteiligungs KG, which was organized in Germany. The individuals are all United States citizens.

(f) Title of Class of Securities

Common Stock

(g) CUSIP Number

89685A102

Item 2. If this statement is filed pursuant to §§240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:

Not applicable

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Item 3. Ownership

MPM Entity	Shares Held Directly		Shares Issuable Upon Exercise of Warrants Held Directly		Sole Voting Power		Shared Voting Power		Sole Dispositive Power		Shared Dispositive Power		Beneficial Ownership		Percentage of Class
BV IV QP		1,665,193		35,025		1,700,218		0		1,700,218		0		1,700,218		8.3	%
BV KG		64,151		1,349		65,500		0		65,500		0		65,500		0.3	%
AM BV4		47,348		995		48,343		0		48,343		0		48,343		0.2	%
BV IV GP(1)		0		0		0		1,765,718		0		1,765,718		1,765,718		8.6	%
BV IV LLC(2)		0		0		0		1,814,061		0		1,814,061		1,814,061		8.9	%
Luke Evnin(3)		0		0		0		1,814,061		0		1,814,061		1,814,061		8.9	%
Ansbert Gadicke(3)		0		0		0		1,814,061		0		1,814,061		1,814,061		8.9	%
Vaughn M. Kailian (3)		0		0		0		1,814,061		0		1,814,061		1,814,061		8.9	%
James Paul Scopa(3)		0		0		0		1,814,061		0		1,814,061		1,814,061		8.9	%
Todd Foley(3)		0		0		0		1,814,061		0		1,814,061		1,814,061		8.9	%

(1) Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP and 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG. The warrants listed above are exercisable within 60 days of the date of this filing. The Reporting Person is the direct general partner of BV IV QP and BV KG.

(2) Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. The warrants listed above are exercisable within 60 days of the date of this filing. The Reporting Person is the indirect general partner of BV IV QP and BV KG and the manager of AM BV4.

(3) Consists of 1,665,193 shares of Common Stock and 35,025 shares of Common Stock issuable upon exercise of warrants held by BV IV QP, 64,151 shares of Common Stock and 1,349 shares of Common Stock issuable upon exercise of warrants held BV KG and, 47,348 shares of Common Stock and 995 shares of Common Stock issuable upon exercise of warrants held by AM BV4. MPM IV GP and MPM IV LLC are the direct and indirect general partners of BV IV QP and BV KG and MPM IV LLC is the manager of AM BV4. The Reporting Person is a member of MPM IV LLC.

Item 4. Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following  ¨.

Item 5. Ownership of More than Five Percent on Behalf of Another Person

Not Applicable

Item 6. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person.

Not Applicable

Item 7. Identification and Classification of Members of the Group

Not Applicable

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Item 8. Notice of Dissolution of a Group

Not Applicable

Item 9. Certification

Not Applicable

Page 14 of 16

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: February 4, 2015

MPM BIOVENTURES IV-QP, L.P.		MPM BIOVENTURES IV GMBH & CO. BETEILIGUNGS KG
By:	MPM BioVentures IV GP LLC,	By:	MPM BioVentures IV GP LLC,
	its General Partner		in its capacity as the Managing Limited Partner
By:	MPM BioVentures IV LLC,	By:	MPM BioVentures IV LLC,
	its Managing Member		its Managing Member
By:	/s/ Luke Evnin	By:	/s/ Luke Evnin
	Name: Luke Evnin		Name: Luke Evnin
	Title: Member		Title: Member
MPM ASSET MANAGEMENT INVESTORS BV4 LLC
By:	MPM BioVentures IV LLC
	its Manager
By:	/s/ Luke Evnin
	Name: Luke Evnin
	Title: Member
MPM BIOVENTURES IV GP LLC		MPM BIOVENTURES IV LLC
By:	MPM BioVentures IV LLC,	By:	/s/ Luke Evnin
	its Managing Member	Name:	Luke Evnin
		Title:	Member
By:	/s/ Luke Evnin
Name:	Luke Evnin
Title:	Member
By:	/s/ Luke Evnin	By:	/s/ Ansbert Gadicke
	Name: Luke Evnin		Name: Ansbert Gadicke
By:	/s/ Vaughn M. Kailian	By:	/s/ James Paul Scopa
	Name: Vaughn M. Kailian		Name: James Paul Scopa
By:	/s/ Todd Foley
	Name: Todd Foley

EXHIBITS

A: Joint Filing Agreement

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