This is a prospective, non-randomized, single arm, multicenter, observational study to assess the initial clinical experience with the Harmonic ACE®+7 Shears by evaluating vessel sealing during laparoscopic colectomy. The study will not modify or influence current surgeon technique. Investigators will perform each procedure using the device in compliance with their standard surgical approach and product labeling.

The Harmonic ACE®+7 Shears is cleared for commercial distribution and will be used in accordance with approved product labeling. The Harmonic ACE®+7 Shears will be assembled, calibrated, and/or used in accordance with manufacturer design specifications, product instructions and guidelines.

Study Population: Subjects enrolled into this study will undergo elective laparoscopic colectomy wherein dissection and transection of the (inferior mesenteric artery) IMA is indicated.

Primary Variable: Incidence of hemostasis at the IMA Secondary Endpoint: Incidence of hemostasis at the inferior mesenteric vain (IMV).

Definition: Hemostasis of the IMA and IMV is a dichotomous variable (i.e. yes or no). "Yes" is defined as a single activation of the Advanced Hemostasis Mode to transect and seal the IMA and IMV.

Additional exploratory endpoints include:

The percentage of subjects requiring additional measures to obtain hemostasis on the IMA and/or IMV, if identified:

• Number of Harmonic touch ups - frequency of Harmonic reapplications required due to oozing or bleeding at initial transection of named vessels
• Use of other energy devices (tissue sealers, cautery devices) - Graded as yes or no; if "yes", the type, transection time (using stopwatch), time of application (24 hour clock)
• Use of hemostatic products (e.g. hemoclips, staples, sutures, fibrin sealants) - Graded as yes or no; if "yes", the type and name of product, number/volume, and time of application (24 hour clock)

Summary of the use of additional treatment after first pass hemostasis has already been achieved at the IMA and IMV. Graded as yes or no; if "yes", the type, number/volume, time of application (24 hour clock) and rationale for use.

Adverse events attributed to the study device or procedure will be collected from time of surgery to Visit 4 (Approximately 4 weeks after study surgery or as per standard of care (SOC)).

Sample size: No formal sample size determination is required for this study. Approximately 40 subjects from the United States and the European Union are planned to be enrolled into this study.

Global indication for use of the The Harmonic ACE®+7, 5mm Diameter Shears with Advanced Hemostasis:

Indicated for soft tissue incisions when bleeding control and minimal thermal injury are desired. The instruments can be used as an adjunct to or substitute for electrosurgery, lasers and steel scalpels in general, plastic, pediatric, gynecologic, urologic, thoracic, exposure to orthopedic structures (such as spine and joint space), sealing and transection of lymphatic vessels, and other open and endoscopic procedures. The instruments allow for the coagulation of vessels up to and including 7mm in diameter, using the Advanced Hemostasis function.

Inclusion Criteria:

1. Indicated for elective laparoscopic colectomy
2. Planned dissection and transection of the IMA
3. Age: equal to or more than18 years

Exclusion Criteria:

Preoperative exclusion criteria:

1. Known or suspected uncontrolled bleeding disorders

2. Subjects unlikely to comply with protocol procedures or adhere to the study visit schedule

3. Any condition rendering a subject unable to understand the nature, scope, and possible consequences of the study or study procedures, or

4. Any Subject unwilling to sign the study informed consent document

   Intra-operative exclusion criteria:

5. Prior to transection of the IMA, the investigator prospectively concludes the inability to safely isolate and transect the IMA with exclusive use of study device while adhering to the instructions for use, or

6. Any intra-operative findings identified by the surgeon that may preclude conduct of the study procedure

Safety Set - all subjects in whom the procedure was started.