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\begin{document}

\title{Prospective randomized trial of endoscopic vs open radial artery harvest
for CABG: clinical outcome, patient satisfaction and mid-term RA graft
patency.}



\author[1]{Muhammed  Tamim}%
\author[1]{CHRISTOS ALEXIOU}%
\author[1]{Donya Al-Hassan}%
\author[1]{Khaled Al-Faraidy}%
\affil[1]{King Fahd Military Medical Complex}%


\vspace{-1em}



  
  \date{May 23, 2024}


\begingroup
\let\center\flushleft
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\selectlanguage{english}
\begin{abstract}
Background and Aim Endoscopic radial artery (RA) harvest (ERAH) is an
alternative to open RA harvest (ORAH) technique. Our aim was to compare
clinical outcome, patent satisfaction and 1-year angiographic patency
rates after ERAH and ORAH. Patients and methods 50 patients undergoing
multivessel CABG were prospectively randomized to two groups. In the
ERAH group (25 patients) the RA was harvested endoscopically and in the
ORAH group (25 patients) openly. Results There were not differences
between the groups in preoperative characteristics. Length of skin
incision was shorter in ERAH (p\textless{}0.001) but there were not
differences in the length of RA, harvest time, blood flow and
pulsatility index after ERAH and ORAH. Wound healing was uniformly
smooth in ERAH and there were 2 haematomas and 1 infection in ORAH.
Postoperatively, major neuralgias were present in 5 patients in ORAH and
none in ERAH (p=0.05) and minor neuralgias in 11 and 3 patients (p=0.02)
respectively. Twenty-four patients in ERAH and 4 in ORAH graded their
experience as excellent (p\textless{}00001). One-year angiographic RA
patency was 90\% without intergroup difference. Target vessel stenosis
\textless{} 90\% adversely affected RA patency (p\textless{}0.0001).
Conclusions In expert center, ERAH has no negative impact on time
harvest, length and quality of RA conduit. Moreover, ERAH may provide
better wound healing, and is associated with less neuralgias, excellent
cosmetic result and better patient satisfaction. RA graft patency is
unaffected by the harvesting technique and is excellent when placed to a
target coronary artery vessel with stenosis \textgreater{} 90\%.%
\end{abstract}%



\sloppy


\textbf{INTRODUCTION}

Radial artery (RA) has been initially used in the early 1970s (1) but
was abandoned because of high incidence of early graft failure and
suboptimal clinical outcomes (2). Following better understanding of the
anatomy and physiology of the RA, namely the thickness and the
reactivity of its muscular wall rendering it prone to spasm and the
beneficial effects of vasodilating agents and calcium channel blockers
in preventing vasospasm (3-5) RA has since 1990s been established as a
reliable arterial graft superior to saphenous vein and in some reports
even comparable to internal mammary artery for CABG (6-11).

Initially RA has been harvested with an open technique (12), however
encouraged by the good outcomes observed with endoscopic harvest of the
long saphenous vein (SVG) (13), surgeons have also applied endoscopic
techniques to harvest the RA (13,14,15,16).

The aim of our study was to compare the clinical outcome, the degree of
patient satisfaction and one-year angiographic RA patency rates in two
cohorts of patients that were prospectively randomized to undergo
multivessel, first time, elective CABG using (amongst other conduits) RA
that was harvested using endoscopic or open techniques.

\textbf{PATIENTS and METHODS}

The study was approved by the Ethics and Research Board Committee of our
hospital (King Fahd Military Medical Complex, Dhahran, KSA) and informed
consent was obtained by all patients involved.

Between 2016 and 2018, 50 patients undergoing isolated, first time,
elective multivessel CABG with the use of one pedicled RA taken from the
non-dominant hand were prospectively randomized, using the envelope
randomization method, to two groups. In the first group (n=25 patients)
the RA was harvested endoscopically. In the second group (n=25 patients)
an open harvest technique was employed. Other types of conduits, such as
LIMA, right internal mammary artery and SVG (harvested also
endoscopically in all patients) were used as required.

These two groups were compared with regard to the following parameters:

\emph{Preoperative} : demographics, comorbid conditions, cardiac
function.

\emph{Intraoperative} : length of skin incision, length of harvested RA,
time harvest of RA, aortic clamping time, cardiopulmonary bypass time,
RA graft flow and pulsatility index.

\emph{Postoperative} : clinical outcome, wound healing (haematomas,
wound discharge, infection), neuralgias (major or minor), vascular
complications, limitation of hand activity (hand function), patient
satisfaction, LV function (transthoracic ECHO) and 1-year RA patency by
means of 64 slice CT angiography.

To assess patient satisfaction a brief questionnaire was filled in by
the patients 12 months after their operation asking them to classify
their overall feeling from the RA harvest procedure in their arm (taking
into account symptoms of pain, neuralgias, numbness, tingling, or any
other symptom, hand function, cosmetic result) into one of the five
categories: poor, average, good, very good and excellent.

\textbf{Assessment of collateral blood flow and exclusion criteria}

Adequacy of collateral ulnar circulation in the non-dominant hand was
preoperatively assessed with a modified Allen's test and a Doppler study
(17-19). Those found to have incomplete palmar arch or inadequate
collateral blood flow were not enrolled. Additional assessment of
collateral flow was also done intraoperatively using a digital oxygen
saturation probe. Excluded were from the study patients with chronic
renal failure already on dialysis or likely to require dialysis in the
future. Patients in whom the RA of the non-dominant has been used for
coronary angiography or other transradial catheterization procedure were
not included in order to avoid the risk of endothelial damage and RA
occlusion (20-21).

\textbf{Endoscopic RA harvest technique}

The RA in all patients of ERAH group was harvested by an expert surgical
assistant who has since 2012 performed a total of 462 cases before
participating in this trial. The same operator has initiated the program
of endoscopic SVG harvesting in our institution in 2010. Currently all
SVG and RA conduits are harvested endoscopically.

\emph{Arm preparation} . The donor arm was shaved and prepared from the
shoulder to the fingers. A Stockinet was placed over the humerus of the
donor arm and a tourniquet applied over the Stockinet and connected to
the insufflation device. Endoscopic harvesting was performed using the
VASO-VIEW\selectlanguage{ngerman}® HemoPro Endoscopic Vessel Harvesting System (Getinge AB,
Maquet Cardiovascular, Santa Clara, CA.).

A longitudinal 2-3cm incision was made in proximity to the wrist crease
over the radial artery. A pressure cuff was applied above the hand and
inflated to 150-200mmHg and both time of inflation and pressure were
monitored and documented. The RA with the venae comitantes were
dissected as one pedicle directly through the lateral fascia. Then, the
endoscope with its conical tip was advanced over the radial artery to
allow for the insertion of the port. The port was inflated with air to
create a seal and carbon dioxide insufflated at a flow rate of 3L/min
and pressure 10-12mmHg to create a tunnel. The anterior aspect of the RA
was dissected first with the aid of the conical tip followed by the
lateral and posterior aspects. The conical tip was then removed, and the
endoscope positioned into the Endoscopic Vessel Harvesting System.
Fasciotomy was done using direct low intensity energy force. Dissection
of the tissues was performed by grasping them between the jaws of the
cannula and gentle traction and rotation of the tool so as to apply
controlled tension. The branches of the RA were caught between the Jaws
by pulling the Toggle into the middle position, all branches were
divided, and the radial artery pedicle was freed from the surrounding
tissues. The proximal part of the RA after it was brought out of the
skin through a 0.5cm long horizontal skin incision it was divided and
ligated. The radial artery was cannulated at the proximal end and 30mg
of papaverine was flushed in it. The radial artery was examined closely
for arterial spasm, bleeding and arterial hematomas. Arterial branches
were ligated before grafting with metal clips. The incision was closed
using 4-0 Vicryl/Monocryl suture.

\textbf{Open RA harvest technique}

A standard open radial artery harvesting technique was performed as
previously described (12). A skin incision was made over the course of
the RA in the forearm of the nondominant hand starting from the felt
pulsation of the artery till its origin from the brachial artery. The RA
was harvested as a pedicle with the venae comitantes using low intensity
monopolar electrocautery. No-touch technique was used, and care was
taken to avoid vessel trauma during surgical manipulation. The side
branches were secured with vascular clips and after haemostasis the
wound was closed using 3/0 and 4/0 Vicryl and monofilament sutures.
Fascia was not closed in order to prevent the occurrence of compartment
syndrome.

\emph{In both techniques} , the dissection was done before
heparinization and RA divided after heparin was given. A soft drain was
inserted in the wound and after skin closure the hand and arm were
wrapped tightly with a bandage. An abdominal pad was placed under the
wrap and the tourniquet deflated and removed. After completion of CABG
and heparin reversal, the tight wrap was taken down and rewrapped
loosely over the entire arm. The proximal anastomosis of RA was
constructed in an end-to-side fashion to the aorta using 7/0 Prolene.
Graft flow and pulsatility index were measured and recorded in all
patients using transit time doppler flowmeter (Medistim, Medtronic,
USA). Calcium channel blockers and oral nitrates were administered
immediately postoperatively and continued for at least 6 months after
surgery.

\textbf{Follow-up}

In addition to routine monthly follow-up, the study patients were seen 1
year after their discharge from the hospital. Apart from history taking
and clinical examination, they had 12 lead ECG, transthoracic ECHO and
64 slice CT coronary angiography.

\textbf{RESULTS}

S\textbf{tatistical Analysis}

Continuous variables are expressed as means values with standard
deviation and the proportions as percentages. The differences between
the groups for the categorical variables were compared with chi square
or Fisher's exact test and continuous variables with unpaired Student's
t test or nonparametric test (Kruskal Wallis). A p value of less than or
equal to 0.05 was considered statistically significant. Statistical
analysis was performed using SPSS, version 11, Chicago, IL.

\textbf{Preoperative data}

The two groups had similar demographics, left ventricular function and
prevalence of comorbid conditions such as hypertension, diabetes
mellitus, chronic obstructive airways disease, hyperlipidaemia and
peripheral vascular disease (\textbf{Table 1} ).

\textbf{Intraoperative data}

Harvesting of RA was uneventful in all cases in both groups and no
conversion was necessary from the ERAH to ORAH. There was a
statistically significant difference in the length of incision for RA
harvest (2.4±0.4cm in ERAH vs 24.8±4.4cm in ORAH groups,
p\textless{}0.001), as expected by the design of the study. However, the
length of RA grafts (16.8±3.2cm vs 17.2±2.9cm, p=0.23) and RA harvest
time (31±11min vs 28±12min, p=0.32) were similar in the ERAH and ORAH
groups respectively, as were the duration of cardiopulmonary bypass
(108±32min vs 102±28min, p=0.56) and aortic clamping (63±21min vs
59±18min, p=0.43). Likewise, there were not intergroup differences in
the graft blood flow (ml/min) (51.7±24.1 vs 50.9 ±25.2, p=0.75) and PI
index (2.1±0.8 vs 1.8±0.9, p=0.28). One RA graft in ORAH group required
limited repair with 7/0 Prolene (\textbf{Table 2} ).

\textbf{Types of grafts and distribution of anastomoses to target
vessel}

There were no significant differences in the types of grafts used and
the distribution of each type of graft to coronary artery target vessel.
All 50 patients received 1 RA graft, 1 in-situ LIMA to LAD and 1 SVG. In
addition, 5 patients in ERAH and 6 in ORAH group received right internal
mammary artery (RIMA) conduit. Two patients in each group had their LIMA
also sequentially anastomosed to the diagonal branch. Saphenous vein
grafts were often used to bypass more than one target vessel in both
groups resulting in the construction of 39 and 36 distal anastomoses in
ERAH and in ORAH groups respectively (\textbf{Table 3} ).

Regarding the distribution of RA graft to target vessels, most RA grafts
in ERAH and ORAH groups were placed to obtuse marginal (OM) (n=21),
followed by right coronary artery (RCA) (n=12), ramus intermedius (n=9),
posterior descending artery (PDA) (n=5) and the diagonal branch (n=3),
without significant intergroup differences (\textbf{Table 3} ).

\textbf{Early outcome}

There were no deaths. All patients were discharged home after a mean
hospital stay of 7±1.5 days vs 7±21 days (p=n.s.).

\textbf{Wound healing}

Wound healing was smooth in all patients after endoscopic harvest. In
ORAH group 2 patients developed hematoma and were managed conservatively
and one had infectious persistent discharge (\emph{staphylococcus
epidermidis} ) and was treated with wound dressing and antibiotics.

\textbf{Neurovascular complications, hand function and patient
satisfaction}

Acute ischaemic injury or vascular compromise of the hand were not seen.

At the time of discharge from the hospital, major neuralgias that
restricted hand function were present in 5 patients in ORAH and none in
ERAH group (p=0.05). At the same time point, minor neuralgias (numbness
or tingling) were recorded in 11 and 3 patients in ORAH and ERAH groups
(p=0.02). However, symptoms of neuralgia (minor or major) were no longer
present in any patient of the ORAH or ERAH groups. No patient
experienced vascular compromise, and all had normal hand function at
1-year follow-up. (\textbf{Table 4} ).

The overall patient satisfaction from the outcome of RA harvest at 12
months in ERAH and ORAH groups was graded as follows: poor in 0 vs 0,
average in 0 vs 6 (P=0.02), good in 0 vs 7 (P=0.007), very good in 4 vs
8 (P=0.3) and excellent in 21 vs 4 (P\textless{}0.00001) patients
respectively (\textbf{Table 5)} . All patients in ERAH group were very
pleased with the cosmetic result early and late after surgery.

\textbf{Survival, LV function and angiographic RA patency}

There were no deaths during the follow up period. All patients were
doing well and no major cardiovascular events were recorded. Left
ventricular ejection fraction (EF) assessed with transthoracic ECHO at
12-monthly follow-up was uniformly improved compared to preoperative
status in both groups (55.5±9.8 vs 57.3±12.4, p=0.24).

Twelve months after surgery RA grafts were patent in 45 patients (90\%)
with 2 patients in ERAH and 3 patients in ORAH groups exhibiting
significant (\textgreater{}50\%) stenosis (p=n.s. between groups). The
target coronary artery vessel in ERAH were the OM1 and the RCA and a
stent inserted in both. In ORAH group the target vessel was the OM1 in
one (managed with stent insertion in native OM) and the RCA in two
patients, who were treated with stent insertion in the RA-to-RCA graft
in one and conservatively in the other patient.

\textbf{RA graft patency in relation to preoperative target vessel
stenosis of 90\%}

The stenosis of the target coronary artery vessel to which RA was
grafted was \textless{} 90\% in all five patients that developed RA
graft stenosis at 12 months. Namely, the native vessel stenoses on
preoperative coronary angiography was 70-80\% in all 5 cases.
Conversely, no significant RA graft stenosis was seen on in the
remaining 45 patients in whom the RA was placed to a native target
vessel with \textgreater{} 90\% narrowing (p\textless{}0.0001).

\textbf{DISCUSSION}

This prospective randomized clinical trial shows that in experienced
centre endoscopically harvested RA is safe and provides excellent early
and mid-term clinical and angiographic outcomes bearing some advantages
over the open harvest technique.

The aim of less invasive techniques is to minimize the trauma inflicted
upon the patient without compromising the quality of work and the
clinical outcome. Open RA harvest is a straightforward procedure that
can be readily taught to an average surgeon (12). On the other hand,
endoscopic RAH technique requires different set of skills, time
consuming training and perseverance and is linked with a significant
learning curve (22, 23).

In our unit, the program of endoscopic vein harvest (EVH) was started
first in 2010 and after accumulation of large experience in EVH we
proceeded to ERAH. A senior surgeon and a surgical assistant were
involved in both programs from their outset acquiring in-depth knowledge
and expertise, which they now pass to younger colleagues. As already
mentioned, all ERAH procedures in the study were carried out by the same
surgical assistant.

In this study, wrist skin incision was 2.4cm in ERAH compared to 24.8 in
ORAH, yet the harvest time and the length of the RA graft were similar.
Published data on time harvest for ERAH vs ORAH differs widely. In
accordance with our findings (harvest time 31 vs 28min for ERAH and
ORAH, p=ns), Patel et al reported in their case series similar harvest
time for both groups (26 vs 22min) (15). On the other hand, Fouly in a
retrospectively analyzed cohort of consecutive patients (16) and Kiaii
et al in their prospectively randomized study (24) described
significantly shorter harvest time for ERAH (40 vs 49min,
p\textless{}0.001) and ORAH (36.5 vs 57.5min, p\textless{}0.001)
respectively. Nonetheless, it should be noted that the ORAH times
reported by Fouly (16) and Kiaii (24) (49min and 57min respectively)
were much longer than those reported for ORAH by us and by Patel et al
(15). In contrast, Rahouma et al in their meta-analysis found a longer
harvest time after ERAH with a steep learning curve in inexperienced
hands (22). Wound healing after ERAH was smooth and uncomplicated in all
patients in this study echoing previously published work, which
uniformly describes superior wound healing after ERAH, the obvious
explanation for this being the shorter skin incision and the smaller
dissection planes that are required compared to ORAH (15,16,22,24,25).

We recorded significantly less neuralgias after endoscopic harvest of RA
in the early postoperative period, which could be attributed to smaller
incision resulting in less cutaneous nerves being damaged, and the
efforts made by the experienced surgical assistant to apply a RA
``non-touch'' harvest technique. Our findings are in agreement with
those previously reported in prospectively randomized (24), propensity
score matched (25) and case series (15) studies that reported fewer
neurological complications after ERAH. On the contrary, in his
retrospective study Fouly (16) recorded more cases of superficial radial
nerve injury and hand numbness after ERAH vs ORAH (20\% vs 5.2\%,
P=0.05) and ascribed this to his limited experience in endoscopically
harvesting the RA.

Our data show that, performed in experienced center by expert operator,
ERAH leads to better patient satisfaction than ORAH, which can be
credited to smooth wound healing, lack of neurovascular complications
and the excellent cosmetic result afforded by the endoscopic harvest
technique (24).

The overall RA patency rate of 90\% at 1-year angiographic follow up
(without intergroup differences) in this study is comparable to previous
reports addressing this topic (26-28). Although we examined a possible
effect of several preoperative, intraoperative and postoperative
parameters on RA graft patency, native coronary artery stenosis of
\textless{} 90\% emerged as the only significant factor adversely
affecting RA graft patency (p\textless{}0.00001). This finding is in
line with the results of the large angiographic study by Tatoulis et al
who demonstrated that aorto-coronary RA graft patency is significantly
improved when anastomosed to a coronary artery with a luminal narrowing
of at least 80\% (28).



\textbf{CONCLUSIONS}

The results of this prospectively randomized trial strongly suggest that
in experienced hands the challenges posed by the endoscopic minimally
invasive technique can be overcome without negative impact on the time
harvest, the length and the quality of the RA conduit. Moreover,
endoscopic radial harvesting may provide better wound healing, and is
associated with less neuralgias, excellent cosmetic result and better
patient satisfaction than the open harvesting technique.

The patency of aorto-coronary radial artery graft is unaffected by the
harvesting technique used and is gratifying when placed to a target
coronary artery vessel with stenosis greater than 90\%.

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\textbf{Hosted file}

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