The authors discuss a case of a rare complications of vascular access creation in a hemodialysis patient “ischemic monomelic
neuropathy”. This is an ischemic axonal injury to the nerves supplying the left hand after arterio-venous graft placement for
hemodialysis. The authors also discuss the diagnosis, pathophysiology and treatment of this rare vascular access complications that
sometimes occurs in hemodialysis patients immediately following arterio-venous fistula or graft (AVF or AVG) placement.
The patient is 73-year Hispanic male with past medical
history of hypothyroidism, type-2 diabetes mellitus, hypertension,
hyperlipidemia, and uremic encephalopathy diagnosed recently for
which he was started on hemodialysis on May 2019. He had a left
upper arm loop graft placed on June,13 2019, immediately after the
surgery the patient complained of pain, numbness and tingling of
the fingers and swelling of the of the left hand. He failed to followup
with his surgeon. In the meantime, his symptoms got worse with
increasing pain and swelling followed by loss of function of the left
hand to the point that he could not grip objects with his hand.
He was referred to the Surgery and Vascular Center at Regency
Park, Toledo, Ohio on the 8/28/2019 for fistulogram with a
diagnosis of vascular steal syndrome. Clinical examination showed
a thin elderly man in no acute distress. His vital signs were within
normal limits. Examination of the cardio-vascular and respiratory
systems were normal. He has a loop graft in the left upper arm with
good thrill and bruits. His radial and ulnar pulses were palpable and
within normal limits. The patient was not able to use the hand and
fingers to grip objects or squeeze the examiner’s hand. He has loss
of sensation over the distributions of the medial and ulnar nerves
with swelling of the left hand (Figures 1-5). The angiogram of the
graft was normal (Figure 6). A preliminary diagnosis of ischemic
monomelic neuropathy was entertained based on the clinical
picture and the normal angiogram of the access. He was referred
for nerve conduction studies and surgical consultation for possible
ligature of the graft.
Ischemic monomelic neuropathy (IMN) is a combined sensory
and motor impairment without major vascular or tissue necrosis.
It is a form of ischemia of the nerves that supply the upper limbs
especially the hand. It occurs immediately after vascular access
creation for hemodialysis patients. It is a rare complication and
caused by ischemic axonal loss of the nerves that supply the distal
arms [1-3]. IMN is first reported by Wilbourn et al in the year 1983
[1]. IMN is under-recognized and mis-diagnosed, but its known
incidence is 0.5 to 3% after vascular creations according to recent
reports [3]. “What the mind cannot conceive the eyes cannot see”.
If a hemodialysis patient complains of hand pain after placement
of arterio-venous fistula or graft, the physician needs to consider
many diseases, including soft tissue swelling, wound hematoma,
carpal tunnel syndrome, vascular steal syndrome, and IMN [4-6].
The most important factor in the diagnosis of IMN is to think of
it and correlate and interpret the symptoms, signs of the clinical
examination of the access and rule out vascular steal syndrome.
Acute pain, weakness, and muscle paralysis immediately after
AVF/AVG placement are common warning signs and symptoms for
the presence of IMN. Since these symptoms are non-specific, after
vascular access creation, the motor and sensory function of the
operated hand should be examined carefully, and nerve conduction
studies should be carried out urgently. Low amplitudes and reduced
or even undetectable motor or sensory nerve conduction velocities
in the presence of preservation of the vascular integrities of the
hand are compatible with IMN. Axonal degeneration of the median,
radial, and ulnar nerves can be observed [3].
Electromyogram (EMG) often show degeneration, including
fibrillation potentials and motor unit loss. Past neuropathy,
diabetes mellitus, atherosclerosis, upper arm vascular access, and
female gender have increased risk for IMN [4,7-9]. These factors
compromise the brachial artery which is the only blood supply
to the distal arm. The most effective treatment of IMN is early
recognition of the condition and immediate closure of the access;
this increase the probability of recovery [1,4]. Early closure of the
vascular access leads to partial or full recovery of the sensory and
motor function of the hand [8]. The easiest way is to tie up the fistula
or graft as soon as possible [5]. Better awareness and education of the surgeons and nephrologists should lead to early diagnosis and
proper management of this dreadful complication (IMN) [4]. So,
educating our minds to conceive the rare complications of vascular
access surgeries are the best way to train the eyes to easily identify
the complications before it is too late to help our patients.