Introduction
Pseudoaneurysm of the palmar arch is a rare pathology in daily clinical practice.[1]
[2]
[3]
[4] Due to the low diagnostic suspicion, it usually goes unnoticed if it does not present
any symptoms. Its pathogenesis is related to a wide variety of possible etiologies,
although within them we want to highlight the traumatic one.
After a clinical assessment of the pathology, the study must be expanded through complementary
tests. The ligation of the nutrient vessels of the aneurysm and its subsequent surgical
resection is usually the general treatment of these lesions.[3]
[5]
We herein present a clinical case in which the diagnostic and therapeutic managements
of a traumatic pseudoaneurysm of the palmar arch were developed.
Clinical case
We report the case of a 39-year-old male patient, without drug allergies, and with
a history of liver cirrhosis of alcoholic etiology and hypertension, who was admitted
due to a decompensation of his underlying pathology; he reported having a 3-month-old
wound on his left hand, caused by a sharp object during an attack.
During the physical examination, a blunt and penetrating lesion, with a granulomatous
appearance, was observed on the volar region of the left hand, measuring 2 × 2 cm.
The wound was located at the level of the thenar eminence, distal to the Kaplan line.
([Figure 1]). At the time of the examination, a pulsating mass was located in the central area
of the lesion without active bleeding, although the patient did spontaneously describe
episodes in the past, without being able to specify their number or duration.
Fig. 1 Image of the pseudoaneurysm prior to surgical treatment. Z incision design.
The patient maintained full functionality of joint balance in both flexion and extension,
which also led us to rule out tendon involvement; No distal abnormalities were detected
in the neurological and vascular examinations. The patient did not present signs or
symptoms of infection, and was in good general condition and afebrile the previous
days. Similar lesions were not evident in other locations on the body, nor did he
present constitutional syndrome, which suggested localized pathology in relation to
the traumatic history. After the anamnesis and physical examination, we decided to
complete the study using CT angiography (CTA) ([Figure 2]).
Fig. 2 Computed tomography angiography image in axial projection: thrombosed traumatic pseudoaneurysm.
A thrombosed pseudoaneurysm was reported in the superficial palmar arch region ([Figure 3]) at the level of the arch between the digital artery of the second space and the
digital artery of the first space. It was defined as a rounded lesion measuring 14 × 17 mm
(measured axially), without contrast enhancement and underlying the skin. The patency
of all interosseous branches, collateral branches, and the rest of the segments of
the superficial palmar arch was also studied, including the integrity of the deep
palmar arch. After the diagnosis of pseudoaneurysm of the superficial palmar arch,
surgical treatment of the injury was chosen.
Fig. 3 Three-dimensional (3D) computed tomography angiography image: superficial palmar
arch.
In the operating room, locoregional anesthesia was used, along with elevation ischemia.
The edges of the wound were expanded using a Z incision, and the slough of the wound
was debrided. Once the superficial palmar arch and the neurovascular bundle were located
through plane dissection, the nutritional vessels on the first/second ray and the
vessels of the ulnar collateral bundle of the second finger were ligated using hemoclips,
respecting the collateral nerves. After ligation, the pseudoaneurysm was resected.
Despite the good condition of the palmar region after surgery, and without evidence
of perilesional pathological tissues, we decided to send the sample to Pathological
Anatomy.
A 1-cm skin defect was left exposed in the suture for secondary healing. Correct distal
capillary refill was evident after removal of the ischemia, and the presence of bleeding
vessels was ruled out.
The result of the histopathological study of the sample defined a lesion of soft consistency
composed of numerous vascular structures of variable size, tortuous and with thin
walls, covered by monolayer flat endothelium, without associated atypia. It had a
leukocyte count per field lower than 5. and the bacteriological culture was negative
after 15 days of incubation in the laboratory. The patient continues with a regimen
of ongoing wound care in outpatient consultations, showing a correct evolution.
Discussion
The vascularization of the hand is a double-flow system due to the participation of
the radial artery and the ulnar artery after passing through the wrist: the radial
artery runs through the pulse channel (delimited ulnarly by the tendon of the brachioradialis
muscle and radially through the flexor carpi radialis), and the ulnar artery passes
through the Guyon canal (next to the ulnar nerve).[1]
The ulnar artery is the vessel that most frequently develops aneurysms and pseudoaneurysms.[2]
[3]
[4]
[5] Moreover, the phalanges (digital arteries) are described as the anatomical region
most prone to developing aneurysms and pseudoaneurysms.[4]
There is no “typical patient” in whom to suspect such pathology;[6] in fact, it can occur in the elderly, adults, and children, with no difference regarding
gender.[7] The great variability, combined with its low incidence, sometimes causes a delay
in diagnosis.
Aneurysms present a joint involvement of the three walls of the vessel (intima, media
and adventitia), generating, in most cases, a fusiform morphology that maintains a
continuous and turbulent arterial flow.[4] On the other hand, pseudoaneurysms are due to an incomplete lesion of the architecture,
localizing the involvement in the internal wall.[6] The vascular defect of the intimal layer generates the formation of a cavity parallel
to the arterial lumen, which increases in size until its distension causes its rupture.
Unlike true aneurysms, “false aneurysms” present a higher rate of rupture and, therefore,
spontaneous active bleeding, such as the case herein presented.[6]
The etiology of pseudoaneurysms is very broad and, in many cases, unknown. Within
the traumatic etiology, different direct and indirect mechanisms are described,[5] with direct trauma being characteristic, both single and external.[3]
Cases secondary to surgery have been described. Gull et al.[4] reported a case in which, in the immediate postoperative period of carpal tunnel
decompression, a tension pseudoaneurysm developed, which was ultimately treated endovascularly.
On the other hand, González Martínez et al.[7] presented a pseudoaneurysm of the ulnar artery after the same intervention, although
in this case, with a surgical resolution.
The performance of a differential diagnosis, with tumor, dermatological and infectious
pathology due to the characteristics of the lesion, is recommended. In the case herein
described, the patient had analytical controls and constants in range, which is why
no systemic infectious pathology was suspected. Despite this, samples of superficial
exudate from the wound were analyzed, which ruled out infection and/or superinfection
of the lesion. Dermatology professionals performed a detailed physical examination
and a study of the lesion, ruling out dermatological tumor pathology. However, they
recommended histopathological and bacteriological studies of the lesion after its
definitive treatment.
After the suspected diagnosis of pseudoaneurysm, a series of complementary tests are
performed. Bouvet et al.[8] presented a diagnostic algorithm in 2018. The authors defend that the first diagnostic
step is ultrasounds, and the rest of the complementary tests depend on the symptoms
and/or signs of acute ischemia that the patient presents. If they are present, they
decide on arteriography. On the other hand, if there are no symptoms, the most commonly
used techniques, due to their great sensitivity, discrimination and fewer complications,
are nuclear magnetic resonance and CTA.[8]
Within the range of options, arteriography is the most sensitive technique, since
it describes the anatomy in greater detail than the rest.[3] However, it tends to be used as a second-line imaging test due to the thrombotic
complications described in the literature, which could jeopardize the viability of
digital circulation.[3]
[5] There are published cases in which arteriography has greater importance, being an
urgent treatment option. It consists of embolization of the pseudoaneurysm using coils.[4] In the clinical case herein reported, the option of arteriography as a therapeutic
method was ruled out by the Vascular Surgery professionals.
The proposed treatment for the present pathology is the surgical option ([Figure 4]). The ligation of the nutrient vessels of the aneurysm, together with its resection,
would be the main treatment. In selected cases, excision can be complemented with
an end-to-end suture of the resected ends, with the aim of maintaining acceptable
flow of the digital arteries.[9] The decision to perform this surgical act depends on the collateral vascularization
that the patient presents, as well as the time of evolution of the injury and its
characteristics.[3]
[5]
[8] Due to the permeability of the collateral vascularization and the 3-month evolution
of the injury, ligation was chosen without any additional steps regarding suture of
the ends.
Fig. 4 Intraoperative image of the ligation of the nutrient vessels. The pseudoaneurysm
is exposed using the dissecting forceps.
Bypass via vascular graft is also an alternative.[8] The option of reconstructing the vascular defect using a venous graft presents a
high risk of long-term reocclusion,[10] which is why an arterial graft is preferred, and, in studies such as the one by
Smith et al., the authors opted for an autologous fragment of the inferior epigastric
artery.[11] In relation to the clinical case herein reported, in the absence of involvement
of the deep arch (studied by CTA) and due to the time of evolution, reconstruction
of the palmar arch was not performed.
On the other hand, the ultrasound-guided percutaneous treatment is proposed by injecting
thrombin derivatives into the pseudoaneurysmal sac,[6] presenting considerable effectiveness and safety results, although in a very small
population.[4]
[6]
The evolution of the patients after resection and ligation of the pseudoaneurysm is
acceptable.[2] In the case herein described, the patient retained sensation and motor function
in all digits, without presenting symptoms at rest or related to regular hand mobility.
During follow-up, the cutaneous defect closed by second intention after surgery, following
proper wound care in outpatient consultations.
Regarding anticoagulation, there is controversy regarding the decision to administer
anticoagulation and antiplatelet therapy after pseudoaneurysm ligation. Pilar Aparicio
et al.[3] mentioned that the decision usually relies on the experience of each hospital center.
In the case herein presented, considering the high risk of bleeding due to the patient's
history of liver cirrhosis and thrombocytopenia, we decided not to administer antiplatelet
or anticoagulant therapy postoperatively.
Conclusion
Palmar arch pseudoaneurysm is a clinical and surgical challenge. The great variety
of diagnostic and therapeutic options without unified criteria explains the need for
further study of the pathology.
This fact is compromised due to its low incidence and, therefore, the limited literature.
Hence, differential diagnosis and high diagnostic suspicion are essential for its
correct treatment.
At present, ligation of the nutrient vessels and subsequent resection of the aneurysm
are the most used treatment and the one that presents the best functional results.
