surgical outcomes of ruptured middle cerebral artery bifurcation aneurysms and factors influencing

92 Pages·2017·1.9 MB·English

SURGICAL OUTCOMES OF RUPTURED MIDDLE CEREBRAL
ARTERY BIFURCATION ANEURYSMS AND FACTORS
INFLUENCING THEM-AN INSTITUTIONAL EXPERIENCE OF
100 CONSECUTIVE CASES

Submitted for M.Ch Neurosurgery
By
Dr. R.GOPIKRISHNAN
October 2017
Department of Neurosurgery
Sree ChitraTirunal Institute for Medical Sciences & Technology
Thiruvananthapuram – 695011
SURGICAL OUTCOMES OF RUPTURED MIDDLE CEREBRAL
ARTERY BIFURCATION ANEURYSMS AND FACTORS
INFLUENCING THEM-AN INSTITUTIONAL EXPERIENCE OF
100 CONSECUTIVE CASES

Submitted by : Dr. R.GOPIKRISHNAN
Programme : MCh Neurosurgery
Month & year of submission : October 2017
CERTIFICATE

This is to certify that the thesis entitled “Surgical outcomes of
ruptured Middle Cerebral Artery bifurcation aneurysms and factors
influencing them-An institutional experience of 100 consecutive cases”
is a bonafide work of Dr.R.Gopikrishnan , conducted in the Department of
Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences &
Technology, Thiruvananthapuram (SCTIMST), under my guidance and
supervision.

Prof. Mathew Abraham
Professor and Head of the Department
Department of Neurosurgery
SCTIMST, Thiruvananthapuram
DECLARATION
This thesis titled “Surgical outcomes of ruptured Middle Cerebral
Artery bifurcation aneurysms and factors influencing them-An
institutional experience of 100 consecutive cases”, is a consolidated report
based on a bonafide study of the period from September 2016 to September
2017, done by me under the Department of Neurosurgery, Sree Chitra
Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram.
This thesis is submitted to SCTIMST in partial fulfillment of rules and
regulations of MCh Neurosurgery examination.

Dr. R.Gopikrishnan,
Department of Neurosurgery,
SCTIMST, Thiruvananthapuram
ACKNOWLEDGEMENT
The guidance of Prof. Mathew Abraham, Professor and Head of the
Department of Neurosurgery, has been invaluable. I am extremely grateful
and indebted for his contributions and suggestions, which were of
invaluable help during the entire work.. His critical remarks, suggestions,
helped me in achieving a high standard of work.
I owe a deep sense of gratitude to Prof.Suresh Nair for his invaluable
advice, encouragement and guidance, without which this work would not
have been possible. He will always be a constant source of inspiration to
me.
I am deeply indebted to Prof. Easwer H. V., Prof. Krishnakumar K.,
Dr. George Vilanilam, DrJayanandSudhir, Dr. Prakash Nair, Dr.Tobin
George and my colleagues .I thank them for their constant encouragement
and support.
TABLE OF CONTENTS

1. Introduction ........................................................................... 1
2. Review of Literature ............................................................. 2
3. Aims and objectives ............................................................ 23
4. Materials and Methods ........................................................ 24
5. Results ................................................................................ 29
6. Discussion ........................................................................... 52
7. Limitations .......................................................................... 61
8. Conclusion .......................................................................... 62
9. References........................................................................... 63
10. Annexures ........................................................................... 71
i. Data collection sheet
ii. Originality report
iii. IEC approval letter
iv. Key to Master chart
v. Master chart
Introduction

INTRODUCTION
Middle cerebral artery aneurysms are one of the most commonly
encountered aneurysms in neurosurgical practice. The MCA bifurcation
aneurysms make up for a majority of aneurysms in the middle cerebral
artery (MCA). They are commonly complex, relatively superficial, lack
collaterals and giant sized making them a unique surgical challenge. Studies
have been published on both bled and unbled MCA aneurysms. In this study
we focussed on patients with bled MCA bifurcation aneurysms, their
clinical presentation, imaging features, modifiable and non-modifiable
factors that will possibly affect outcome.
1
Review of Literature

REVIEW OF LITERATURE
Microsurgical anatomy of MCA
Middle cerebral artery (MCA) is the largest and most direct branch of
the internal carotid artery (ICA). It courses approximately 1 cm posterior to
the sphenoid wing. Within the Sylvian fissure, it makes a sharp postero-
superior turn at the limen insula to reach the surface of the insula. At the
periphery of the insula, the branches of the MCA pass to the medial surface
of the opercula of the frontal, temporal, and parietal lobes. Finally it runs
over the brain surface as cortical branches. The MCA is classically divided
into 4 segments. These are the M1 or sphenoidal segment, the M2 or insular
segment, the M3 or opercular segment, and the M4 or cortical segment. The
M1 segment was subdivided into a pre-bifurcation and post- bifurcation
part. The pre-bifurcation segment was composed of a single main trunk that
extended from the artery's origin to its bifurcation. The bifurcation occurred
proximal to the genu in 86% of hemispheres1. In contrast to this, Ture et al2
found that the main bifurcation is located at the genu in 57.5% of the
hemispheres, distal to the genu in 27.5% and proximal to the genu in 15%.
Though classically M2 segment origin has been defined from the genu of
MCA at the limen insula, some authors consider the point of MCA
bifurcation as the origin .The MCA divides into superior and inferior trunks
2
Review of Literature

at the level of the limen insula and these trunks course over the insula as the
M2 segment. The superior and inferior trunks may be equal in diameter, or
one of them may be larger than the other. According to Umansky et al,3
there are 4 types of branching patterns
a) Cortical branches arise as collateral vessels from a single trunk that
terminates in the angular artery (6%)
b) The MCA divides into the superior and inferior trunks (64%).
c) The MCA divides into the superior, middle, and inferior trunks (29%)
d) The MCA divides into 4 trunks (1%).
In the study reported by Gibo et al1, 78% of the MCAs divided into a
bifurcation, 12% divided into a trifurcation, and 10% divided into multiple
trunks. M2 segment give rise to 8 to 12 branches, mainly arising from the
superior trunk, before becoming M3 segment. The superior (frontal) M2
branch is the origin of the prefrontal, pre-central, and central arteries. In
22.5% of 11 hemispheres dissected by Ture et al2 ,the anterior and posterior
parietal arteries have their origin in the superior M2 segment branch. The
inferior (temporal) M2 segment branch is the main origin of the posterior
and middle temporal arteries. M3 (opercular) segments start at the
peri‐insular sulci and end at the lateral surface of the brain. M4 (cortical)
3
Review of Literature

segments are the distal branches over the cortical surface. The M5 segment
is the terminal segment.
A new entity called the intermediate trunk has been proposed which
can arise from the superior or inferior trunk, the branches of which supply
the motor cortex4
Approximately 80% of the Lenticulostriate branches arise from the
pre bifurcation part of the M1. Most of the remainder arise from the post
bifurcation part of the M1, but a few arise from the proximal part of the M2
near the genu. The lenticulostriate arteries are divided into medial,
intermediate, and lateral groups. The lateral lenticulostriate arteries are
present in almost all hemispheres. They originate predominantly on the
lateral part of the M1, pursue an S‐shaped course, and enter the
posterolateral part of the anterior perforated substance. They may also arise
from the early branches of the M1 or from the M2. They may be
inferomedial, in close relation to the aneurysm base in case of an inferiorly
projecting MCA bifurcation aneurysm5.

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