Cardiopulmonary bypass technologies - Biomaterials and Devices for the Circulatory System - page 162

that morbidity compared with CPB would be dramatically lower. That this
has not been apparent from several randomized trials has surprised many,
but may refl ect all the small, subtle improvements in anesthetic and surgi-
cal techniques and equipment (e.g. design of pumps, oxygenators, and
cannulae) that have taken place over the last ten years. In high risk
groups, particularly those with renal impairment, off-pump surgery makes
the need for post-operative renal support less likely. In groups over 70
years of age, there is a reduction in the incidence of cerebral injury when
an off-pump technique is employed. 44 It is also apparent that off-pump
surgery is an exacting technique that takes time to perfect, but can
produce a graft quality equivalent to that obtained on-pump. Off-pump
coronary surgery is as safe as on-pump surgery, and in experienced hands
offers fewer early complications, particularly in those patients with signifi -
cant comorbidity.

6.7.3 Minimally invasive surgery and robotics

Minimally invasive techniques for coronary artery bypass surgery are of
intense clinical interest today. These techniques are primarily aimed at
reducing the morbidity related to the sternotomy incision. Early efforts of
minimally invasive procedures were conducted with CPB; however, today
most of these procedures are done in an 'off-pump' setting. 45
Since 1997, endoscopic open heart surgery: video-assisted controlled by
a voice-activated camera arm and by robotic telemanipulation and three-
dimensional endoscopy has started. For these operations peripheral arterial
and venous cannulation, kinetic venous drainage, thin-walled high-fl ow can-
nulas, a 5 cm right minithoracotomy, and a newly developed transthoracic
aortic clamp are used.
In these operations, the entire surgery is done endoscopically with the
surgeon operating from a console placed 3 m from both the patient and
assistant surgeon. 46 Now the trajectory is unknown; however, part of these
minimally invasive techniques, telemanipulation methods and robotic
devices will be a part of the armamentarium for future surgeons.

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6.7.4 Novel indications of cardiopulmonary bypass

Despite early enthusiasm for use of CPB as an adjunct in a variety of surgi-
cal cases, the primary use currently is to facilitate the surgical correction of
cardiac and aortic lesions. Certain neurosurgical, urologic, and thoracic
procedures are feasible only when systemic oxygenation is supplied through
CPB. Rewarming following an accidental hypothermia, support of interven-
tional procedures in cathlab and the use of CPB for resuscitation in emer-
gency room are life-saving.