Clinical
Studies
Results
The results of clinical studies carried out at Leeds
General Infirmary, Yorkshire and Derriford Hospital, Plymouth
have been published in 2005.
Both studies have compared the
efficacy of Lotus™ with “conventional” haemostatic
surgical instruments, namely bipolar diathermy and the
leading conventional ultrasonic scalpel.
Randomised Clinical
Trial of Longitudinal versus Torsional Mode Ultrasound
in Laparoscopic Cholecystectomy
Ching SS,
McMahon M.J, LIMIT, Yorkshire.
In
Leeds, Professor McMahon’s
team has compared a number of aspects of laparoscopic
cholecystectomy performed using Lotus™ or the Harmonic
Scalpel supplied by Ethicon EndoSurgery.
A twenty patient randomized study compared the following
aspects of surgery when performed using the two devices:
It was found that using Lotus™ resulted
in a range of blood loss from 0 to 178ml with a median
value of 7.1ml. This is to be compared with a range of
blood loss of 0 to 925ml when the Harmonic Scalpel is used
(with a median of 21.5ml).
In addition, Lotus™ appeared
to reduce the excision time from between 7 and 43 minutes
(median 19.5 minutes) with the Harmonic Scalpel, to between
5 and 41 minutes (median 11 minutes) with Lotus.
Due largely to the small sample
size p>0.05 for the
two sets of data respectively. To reduce the p value to
the order of 0.05 a larger follow up study has been proposed,
approved by ethics and research committees and is already
underway.
The results were presented as a poster at the EAES in
Venice 2005.
A Clinical Evaluation of the Lotus™ Ultrasonic Shears in Gynaecological Surgery
Awadzi G, Frappell
J, Oriolowo A, Sibanda T, Derriford, Plymouth
In Plymouth, Mr. Frappell’s
team has compared the division time and degree of thermal
damage caused in the immediate vicinity of dissections
of large ligaments during abdominal hysterectomy and
bilateral salpingo-oophorectomy.
In a ten patient study the round and
infundibulopelvic ligaments on one side were divided using
Lotus™ and those on the other side were divided using
Power Blade™ cutting bipolar forceps. Two hundred histological
samples were prepared from the excised samples by the blinded
histopathologist and, using a protocol devized by the team,
severity of cell damage and spatial extent from the point
of energy application were quantified.
It was found that Lotus™ was as
fast at cutting the Round Ligament as the Power Blade™ (mean
time c.9s.) and faster at cutting the Infundibulopelvic
Ligament (20s. versus 27.5s.). (p=0.1688)
The degree of thermal damage caused by Lotus™ was less
than that caused by Power Blade™ at 2mm and 6mm from
the application site. No thermal damage was seen 10mm from
the application site for both devices.
Both instruments were equally effective in securing haemostasis
in all the pedicles.
Again, due to the small sample size the results were
not statistically significant.
The results were presented in a talk by G.Awadzi at the
BSGE in London in 2005.
Further Studies
Both institutions are already following
up with new clinical studies about to get underway:
Study Comparing the Burst strengths of Blood Vessels
Sealed with Longitudinal and Torsional Ultrasonic Devices
Ching SS, McMahon MJ, LIMIT, Yorkshire.
Comparison of vessel seal burst pressures
achieved using Lotus™ and Harmonic ACE
Whitehead E, Hosie K, Derriford,
Plymouth
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