student research day - Case Western Reserve University School of ...

Kelsey Rohlck
Left Upper Quadrant Laparoscopic Instrument Insertion Angle: Abdominal Anatomy Characterization By Magnetic
Resonance Imaging.
Kelsey Rohlck, V. Gulani. N. Giannios, R. Flyckt and Dr. William W. Hurd
Ob/Gyn and Radiology
University Hospitals Case Medical Center
Objective The left upper quadrant (LUQ) is an alternative site for Veress needle and primary trocar
placement for patients at increased risk for intra-abdominal adhesions. Instruments are place into
the abdomen at Palmer’s Point, 3 cm below the left subcostal margin in the midclavicular line. In
the axial plan, it is recommended that the instruments be inserted perpendicular to the surface of
the abdomen. In the sagittal plane, various angles of insertion from vertical to 45º toward the
lower abdomen have been recommended. However, little is know about the dimensions of the
abdominal cavity beneath Palmer’s point and thus the safest angle for instrument insertion is
uncertain. This study was designed to determine the angle of insertion of laparoscopic instruments
at Palmer’s point that is least likely to injure retroperitoneal structures and to determine if this
angle should be varied according to the patient’s body mass index (BMI).
Methods Abdominal magnetic resonance images were reviewed for 78 women between 18 and 50
years of age. Abdominal wall thickness at Palmer’s point and the distance from the skin at this
point to the retroperitoneal structures were measured vertically (0º), at 30º and at 45º from
vertical toward the lower abdomen. The results were correlated with body mass index (BMI). The
location of the aortic in relation to the line of insertion was also determined.
Results The abdominal wall thickness ranged from 1.1 to 5.1 cm and correlated positively with BMI. The distance from the
skin to the retroperitoneal structures ranged from 7.1 to 23.6 cm and correlated positively with BMI and angle of insertion. A
Veress needle or trocar inserted to its complete 11 mm length would contact retroperitoneal structures in 35% of patients if
inserted vertically (0º), 23% at 30º, and 1% at 45º. In the axial plane, the insertion line perpendicular to the abdominal wall
was always lateral to the aorta.
BMI
(kg/m2)
30
(N=15)
Abdominal wall
Thickness
(cm)
2.19
(range 1.1-3.8)
2.9
(range 1.5-4.2)
3.87
(range 2.0-5.1)
Distance from skin to retroperitoneal structures (cm)
Vertical (0º) 30º from vertical 45º from vertical
10.5
(range 7.1-14.0)
11.8
(range 8.6-15.9)
13.2
(range 9.5-16.7)
73
12.1
(range 8.2-16.2)
13.6
(range 9.9-18.4)
15.2
(range 11.0 -19.3)
14.8
(range 10.0-19.8)
16.6
(range 12.2-22.5)
18.6
(range 13.4-23.6)
Conclusions Veress needles and laparoscopic trocars placed through Palmer’s point should be inserted at an
angle of at least 30º from vertical toward the lower abdomen to minimize the risk of injuring retroperitoneal
structures. In women with a BMI