Many physicians involved in the treatment of cancer patients, including surgeons,
interventional radiologists, and other specialists, routinely use central venous access
devices,[1 ] and they are used to treat a wide range of medical conditions. The administration
of drug as chemotherapy, total parenteral nutrition, and poor peripheral venous access
are just a few examples.[2 ]
The central venous catheter should be placed over the right ventricle in the superior
vena cava (SVC). Due to the rapid flow at this level, thrombogenicity is minimized.[3 ] When encountering an abnormal guidewire path after a venipuncture, all physicians
should be aware of the likely anatomical variations,[4 ] thus a complete knowledge of the venous anatomy, including the identification of
congenital venous abnormalities and treatment- or disease-induced changes in thoracic
central venous anatomy, is crucial.[1 ]
[4 ] More than 7% of surgeries result in catheter misplacement, which can lead to life-threatening
complications.[3 ]
Persistent left SVC (PLSVC) is a rare vascular variation that is identified by chance
during central venous access procedures when the left internal jugular vein (IJV)
is used,[5 ] and it may be associated with other congenital anomalies.[2 ]
Here, we present a case of 40-year-old man, who was diagnosed with PLSVC and right
aberrant subclavian artery diagnosed during portacath placement.
Case Description
A 40-year-old man presented 2 months ago for a lump on the right cervical level, whose
ultrasound showed the presence of a right jugulocarotid lymphadenopathy. A biopsy
was performed which revealed the presence of a mixed lymphocyte population and the
presence of Reed–Sternberg cells, confirming the diagnosis of mixed Hodgkin's lymphoma.
Computed tomography and positron emission tomography scan showed disease localized
in his right cervical lymph nodes.
Therefore, the patient was scheduled for a totally implantable vascular access device
(TIVAD) placement. The patient's preoperative work-up was normal, and he was admitted
to the operating room on the same day of his first cycle chemotherapy administration.
Intraoperative ultrasound of the neck confirmed the presence of an enlarged right
cervical lymph node of 5 cm, with compression of the IJV and consequently inability
to puncture the vein. The decision was therefore made for a left catheterization.
Local anesthesia is administered, followed by ultrasound-guided puncture of the left
IJV, insertion of the guidewire, and control of its position in the SVC by fluoroscopy,
according to our own institutional technique.[6 ] Intraoperative fluoroscopy showed that the catheter tracks the left mediastinal
border. Several attempts to alter the path of the guidewire toward the normal right
mediastinal boundary but without success. Considering that the left IJV puncture procedure
went smoothly, we concluded that our guidewire follows the path of a PLSVC, and we
decided to continue the procedure as usual. After preparation of the subcutaneous
area, the dilator was positioned over the guidewire; the catheter and the port were
inserted in place, under fluoroscopy control. Rinsing of the port with normal saline,
good blood reflux and no flow resistance were noted. Connection of infusion. The procedure
went smoothly without difficulty or blood loss, and the patient was transferred to
recovery room for further observation and investigations.
The postoperative frontal chest X-ray preformed, demonstrating the unusual path of
the catheter in the left hemithorax rather than the normal anatomical right side of
the SVC, confirmed the presence of the left SVC ([Fig. 1 ]).
Fig. 1 Frontal chest X-ray showing a portacath with left jugular vein approach and demonstrating
the unusual course of the catheter in the left hemithorax (arrow), rather than in
the right normal anatomical side of the superior vena cava.
A computed tomography of the chest was performed to confirm the diagnosis and look
for any other associated abnormalities. The following images confirm the presence
of the catheter in the PLSVC in addition to the right vena cava in place ([Fig. 2A–C ]).
Fig. 2 Computed tomography scan. (A, B) Axial view demonstrating the catheter in the persistent
left superior vena cava and the right vena cava (curved arrow). (C) Coronal view demonstrating
the catheter in the persistent left superior vena cava (arrow) and the right vena
cava (curved arrow). (D) Axial view showing the left brachiocephalic vein that communicates
the persistent left superior vena cava and the right superior vena cava. (E) Axial
view demonstrating the left superior vena cava draining into the coronary sinus.
It also highlights the communication between the PLSVC and the right one through the
left brachiocephalic vein ([Fig. 2D ]), and confirms the drainage of the former into the coronary sinus. Unfortunately,
it was difficult to present a clear photo because there is not a large amount of contrast
delivered during this chest scan; moreover, the course of the vessel was oblique ([Fig. 2E ]).
Interestingly, another anatomical variant was discovered in this patient; it was an
aberrant right subclavian artery that arises directly from the aortic arch, passing
posteriorly to the esophagus, compressing it slightly anteriorly and having no correlation
with the trachea ([Fig. 3A, B ]).
Fig. 3 Computed tomography scan: axial oblique views demonstrating the origin of the right
aberrant subclavian artery directly from the aortic arch (A) and its relation to the
esophagus (B).
Since the drainage of the PLSVC is confirmed in the coronary sinus and no dysrhythmia
developed, the decision was made to start his first dose of chemotherapy, without
the necessity of further investigations.
The entire chemotherapy protocol was administered through the portacath without any
problem. It was removed 9 months after its insertion.
Discussion
PLSVC is the most common thoracic venous anomaly, despite its rarity among all vascular
malformations. In the general population, the prevalence varies from 0.2 to 3%. In
people with congenital heart disease, the prevalence ranges from 1.3 to 11%.[7 ] Its prevalence does not differ significantly between males and females.[7 ] The prevalence may be higher if PLSVC was not associated with abnormalities such
as hypoplastic thymus and esophageal atresia,[8 ] which can lead to spontaneous abortions and premature births.[7 ] There is an increase in associated chromosomal anomalies, the most common association
being trisomy 18.[8 ]
John Marshall first reported PLSVC in 1850,[1 ] and since then, various hypotheses about its development have been suggested.[7 ] Normally, during the eighth week of embryologic development, a substantial venous
anastomosis forms between the left and right precardinal veins,[5 ] then increased blood flow to the right precardinal vein occurs, allowing it to enlarge.[3 ] The precardinal veins become the IJVs above this anastomosis. The right precardinal
and right common cardinal veins become the SVC below this anastomosis. The left precardinal
vein usually regresses, leaving only a small segment as the left superior intercostal
vein, while the left common cardinal vein becomes the coronary sinus venous system.[5 ] The “low left atrial pressure theory” is one of the theories. The left atrium may
be smaller than expected in the presence of atrial development anomalies, and it will
be unable to fully compress the coronary sinus and left precardinal veins. As a result,
the caudal part of the left superior precardinal vein and the left common cardinal
vein will not regress, and PLSVC will develop.[7 ]
About 20% of the total return of venous blood from the left arm, left side of the
head and neck is handled by PLSVC, and in 80 to 90% of cases, right atrial drainage
is found,[7 ] without associated pathological hemodynamic alterations or clinical symptoms through
a dilated coronary sinus.[9 ] It is symptomatic only if it drains into the left atrium because it bypasses the
lungs; it can predispose to systemic dispersion of emboli (right–left shunting), or
if conduction problems are caused by an expanded coronary sinus[5 ] because its expansion may cause compression of the His bundle and atrioventricular
node, and in addition, it can cause compression of the left atrium and decreased cardiac
output.[7 ]
It is difficult to diagnose on the basis of medical history alone,[3 ] and physical examination may show distension of the left external jugular vein and/or
a heart murmur.[5 ] A range of cardiac abnormalities affect nearly 40% of people with PLSVC,[10 ] including associated atrial septal defect, ventricular septal defect, transposition
of great vessels, aortic coarctation, and tetralogy of Fallot.[1 ]
The presence and thickness of the two SVCs, the presence of both azygos veins, and
the anastomotic ramus were used to classify PLSVC.[11 ] Evers et al used in simplified classification as follow: type I being the normal
anatomy, type II with only a PLSVC and an absent right SVC, type III with the coexistence
of the right and left SVCs, which is further subdivided into IIIa where we can find
a connection between the two SVCs through the left brachiocephalic vein, while IIIb
where the connection between them is absent.[3 ] The presence of both SVCs, a small anastomotic ramus, and paired azygos veins is
the most commonly reported type (20.8%).[11 ]
PLSVC is found incidentally in 75% of cases.[3 ] It can be identified on chest radiography by local enlargement of the mediastinum
superior to the left side of the aortic knob,[12 ] or during cardiovascular imaging or when a central venous catheter is inserted into
the left jugular or subclavian vein.[10 ] Due to local factors that prevented catheterization or port placement in the right
chest, such as breast surgery, radiation therapy, and large metastatic lymph nodes
at the root of the right neck, the left side will be chosen.[13 ]
A chest X-ray reveals an atypical catheter path in the left hemithorax.[2 ] To confirm the diagnosis, computed tomography scan, magnetic resonance imaging,
or invasive angiography can be used.[7 ] Echocardiography is useful to confirm the presence of a dilated coronary sinus and
to rule out variations in the typical aberrant venous route.[10 ] The electrocardiogram can be used to check for cardiac dysrhythmia,[5 ] manifested by both bradycardia and tachycardia.[4 ] In about half of patients, PLSVC plays a significant role in the onset and maintenance
of atrial fibrillation.[7 ] Jheengut and Fan used an intracavitary electrocardiogram to identify the PLSVC.
A negative P-wave was first observed (in lead II), while a biphasic P-wave pattern
appears during catheter insertion.[13 ] PLSVC draining into the left atrium can be identified by injecting agitated saline
into the patient's left arm and observing the timing of left atrial bubbles.[12 ] Venography is essential to confirm PLSVC drainage into right atrium prior to catheterization
when vascular variant anatomy is detected during the procedure.[5 ]
Thermodilution,[3 ] paradoxical arterial embolism (by air embolus or thromboembolus),[13 ] coronary sinus thrombosis, venous stenosis, cardiac arrhythmias, cardiac tamponade,
and cardiac arrest have all been reported following PLSVC catheterization.[5 ] Luckily, they are uncommon.[10 ]
Aside from misplacement in a PLSVC, improper placement in minor veins might create
an anomalous position of the catheter tip near the left edge of the mediastinum. The
left internal thoracic vein, the left superior intercostal vein, the left pericardiacophrenic,[3 ] the levoatriocardinal vein, and the aberrant left brachiocephalic vein are among
them, and they should be considered as differential diagnosis.[7 ] Misinterpretation can lead to an inaccurate diagnosis of catheter malposition, resulting
in unnecessary additional intervention and radiation exposure, as well as delaying
the start of essential treatment.[5 ]
Simple ligation, provided that the right SVC is well-developed intracardiac conduit
and anastomosis of the PLSVC to the right atrium or the pulmonary artery, can all
be used to repair a PLSVC draining into the left atrium. Polytetrafluoroethylene grafts
are also used as a venous replacement.[9 ]
When traditional SVC catheterization is not possible, long-term PSLVC catheterization
is effective, especially after determining the drainage pattern,[5 ] and chemotherapy can be administered safely[13 ]; ensure that the tip of the catheter does not enter or pierce the coronary sinus,[4 ] as the presence of the guidewire, dilator, or catheter nearby can cause arrhythmias.[2 ]
After reviewing the English literature, only 17 cases of PLSVC, diagnosed after insertion
of a portacath, were reported between 2003 and 2021 ([Table 1 ]). The majorities were inserted for chemotherapy administration, and only one was
for parenteral nutrition.[10 ] One of the reported cases had a left atrial drainage and developed a complication
post its first usage.[15 ] None of the reported cases described any associated vascular anomaly.
Table 1
Reported cases of PLSVC diagnosed post portacath insertion
Year
Authors
Age
Sex
Comorbidities
Usage
Diagnostic modality
Drain into
Associated vascular anomalies
Used without complications
2003
Laurenzi et al [14 ]
59
M
Lung Ca
Chemo
Chest X-ray
CS
N/A
4 cycles
8 mo
2010
Dinasarapu et al[15 ]
52
F
Breast Ca
Chemo
CT angiogram
LA
N/A
1 cycle (complication post first usage)
2011
Povoski and Khabiri[1 ]
53
F
Breast Ca
Chemo
IO venography
N/A
N/A
7 mo
2012
Iovino et al[10 ]
66
M
Lung Ca
Chemo
Chest X-ray
N/A
N/A
6 cycles
74
F
Breast Ca
Chemo
Chest X-ray
N/A
N/A
4 cycles
52
F
Pancreatic Ca
TPN
Chest X-ray
N/A
N/A
2 mo[a ]
54
F
Ovarian Ca
Chemo
Chest X-ray
N/A
N/A
6 cycles
2016
Zhou et al[5 ]
37
F
NHL
Chemo
IO venography
RA
N/A
8 mo
2017
Evers et al[3 ]
50
–
Esophagus Ca
Chemo
Chest X-ray
CS
N/A
4 cycles NA
4 cycles postop
2018
Van walleghem et al[4 ]
74
M
Lung Ca
Chemo
IO venography
CS
N/A
N/A
2021
Jheengut and Fan[13 ]
46
F
Breast Ca
Chemo
ECG
N/A
N/A
6 cycles
4 mo
41
F
Breast Ca
Chemo
ECG
N/A
N/A
4 cycles
3 mo
33
F
Breast Ca
Chemo
ECG
N/A
N/A
20 cycles
25 mo[a ]
59
M
Lung Ca
Chemo
ECG
N/A
N/A
20 cycles
7 mo[a ]
57
F
Breast Ca
Chemo
ECG
N/A
N/A
6 cycles
6 mo
41
M
Lung Ca
Chemo
ECG
N/A
N/A
6 cycles
16 mo[b ]
51
M
Lung Ca
Chemo
ECG
N/A
N/A
6 cycles
13 mo[b ]
Abbreviations: Ca, cancer; Chemo, chemotherapy; CS, coronary sinus; CT, computed tomography;
ECG, electrocardiographic; F, female; IO, intraoperative; LA, left atrium; M, male;
N/A, not available; NA, neoadjuvant; NHL, non-Hodgkin's lymphoma; Postop, postoperation;
RA, right atrium; TPN, total parenteral nutrition.
a Patient died before stop usage.
b Patient is still using his port at the time of publication.
Conclusion
PLSVC is a rare congenital vascular malformation, detected incidentally in the majority
of cases and can lead to morbidity and mortality during its puncture and use. We urge
all physicians to keep this differential diagnosis in mind and carefully revise any
available preoperative imaging that may help detecting any vascular anomalies such
as PLSVC.
We reported here the first case of association of vascular anomalies in patient where
we discovered a PLSVC during the placement of TIVAD.
