Keywords
partial splenectomy - laparoscopy - fluorescence - indocyanine green - pediatric
New Insights and the Importance for the Pediatric Surgeon
Laparoscopic partial splenectomy is a technically challenging procedure for the pediatric
surgeon. The use of indocyanine green-mediated fluorescence facilitates dissection
and allows the vascularization of the splenic remnant to be checked, which increases
the safety of the procedure.
Introduction
Splenic cysts are a rare entity in children, and splenectomy is the first choice.
Loss of spleen's immune function is associated with potentially serious complications
such as postsplenectomy sepsis.[1] Partial splenectomy allows the removal of the lesion while preserving splenic function.
However, it is a difficult technique, especially in large and centrally located cysts.[2] The use of minimally invasive techniques reduces the aggressiveness of the procedure,
but there are few cases published of partial splenectomy in children. This is because
it is a technically demanding procedure, especially during vascular dissection. Fluorescence
facilitates a clearer definition of the anatomy and surgical dissection in technically
complicated cases, allowing complex laparoscopic procedures to be addressed with greater
safety for the patient.
We present an unusual case of a child with a hilar splenic cyst in which a laparoscopic
partial splenectomy guided by indocyanine green (ICG) fluorescence was performed.
Case Report
A 13-year-old patient was admitted to our center reporting a 1-year history of diffuse
abdominal discomfort and asthenia. She visited the emergency department due to worsening
pain and vomiting during the last 24 hours. Abdominal examination and blood tests
were normal. An ultrasound scan was performed revealing a 5 × 5.3-cm smooth-edged
oval lesion with hypoechoic content, echoes, and thin septa. Magnetic resonance imaging
(MRI) and computed tomography (CT) ([Fig. 1]) revealed a 5.5-cm lesion located in the anterior pole and diaphragmatic face of
the spleen, in close relationship to the main superior branches of the splenic artery
and vein consistent with an epidermoid cyst. Due to the size of the lesion and the
associated symptoms, a surgical approach was favored. The patient received preoperative
immunization for meningococcus, haemophilus, and pneumococcus.
Fig. 1 Computed tomography with intravenous contrast. Axial (A) and coronal (B) sections in venous phase. A hypodense 48.8 × 55.2-mm lesion with a rounded morphology
was observed in the anterior, cranial, and lateral region of the spleen, intimately
related to the hilum.
The surgical procedure was performed with the patient in supine position with the
left side elevated 45 degrees. A 10-mm umbilical Hasson trocar was inserted by open
technique and three 5-mm accessory trocars were later placed subxiphoid, epigastric,
and on the left flank. Laparoscopic equipment from Stryker Corporation (Michigan,
United States) with a led and near-infrared light source (L10 Led Light Source with
AIM) and 5 mm 30 degrees optics (1588 AIM) was used. Laparoscopy was performed with
a 12 mm Hg CO2 pneumoperitoneum with a 4 L/minute flow rate. The surgeon, assistant, and scrub nurse
were on the right side of the patient.
An orthotope spleen with a large peripheral cyst on its lateral side was found. The
spleen had some adhesions to the diaphragm and abdominal wall. Small accessory spleens
were found on the medial aspect ([Fig. 2]).
Fig. 2 Intraoperative image before beginning dissection. To the left of the image, the left
hepatic lobe is seen covering the upper pole of the spleen. The spleen presents a
large cyst on the superolateral aspect with diaphragmatic adhesions.
The procedure started with bipolar cauterization and section of the short gastric
vessels. Then, dissection of the splenic hilum identifying the splenic artery and
vein was performed. After ligature of the superior branch of the splenic artery, the
fluorescent dye was administered intravenously. ICG-PULSION 25 mg powder for solution
(PULSION Medical Systems, Feldkirchen, Germany) was diluted in 5 mL of bidistilled
water to a concentration of 5 mg/mL. From this dilution, a bolus of 0.2 mg/kg was
administered. Seventy-two seconds after administration, the contrast was observed
in the splenic artery and subsequently fluorescence in the lower-lateral end of the
spleen, while the region corresponding to the cyst remained without uptake ([Fig. 3]).
Fig. 3 Intraoperative image after arterial clamping. Image under near infrared light. To
the right of the dotted line, inferolateral pole of the spleen. It shows fluorescence
since arterial vascularization in this portion is preserved. To the left of the dotted
line, supero-medial pole. It does not show fluorescence as the superior splenic artery,
which supplies arterial irrigation to this portion, has been clamped.
After verifying ICG wash-out through the inferior peripheral polar vessels ([Fig. 4]), the superior branch of the splenic vein was ligated with Hem-o-lock clip (Auto
Endo5, Teleflex, Pennsylvania, United States), ensuring arterial perfusion and venous
return of the splenic segment to be preserved. The spleen was divided above the ischemia
line using Caiman forceps (B. Braun, Melsungen, Germany) until both territories were
separated ([Fig. 5]). Subsequently, the piece was removed with a laparoscopic bag ([Fig. 6]).
Fig. 4 Intraoperative image after venous clamping. (A) Image under LED light. (B) Image under near infrared light. No fluorescence is observed in the inferolateral
pole of the spleen, reflecting adequate ICG wash-out through a permeable venous system.
Some ICG rests can be seen in the omentum (lower part of the image) and stomach (left
edge). ICG, Indocyanine green.
Fig. 5 Intraoperative image. Division of the lateral pole from the medial pole using Caiman
forceps.
Fig. 6 Intraoperative image. Postoperative aspect.
Pathological anatomy reported a 96 g specimen. Macroscopically, normal splenic parenchyma
surrounded a smooth and thin-walled cyst. Microscopic study showed a cyst covered
by a nonkeratinized epithelial lining with an immunohistochemical profile corresponding
to an epithelial cyst.
The postoperative course was uneventful. The patient did not require blood transfusion
and was discharged after 48 hours. Follow-up ultrasound 1 month after surgery revealed
a well-perfused small splenic remnant with no signs of recurrence.
Discussion
Splenic cysts are rare entities. In our setting, up to 90% of primary splenic cysts
are epidermoid (nonparasitic), excluding neoplastic cysts. Most primary splenic cysts
are diagnosed in children or young adults. Symptoms can range from an incidental finding
to life-threatening complications such as rupture, bleeding, or infection. Up to 70%
of cysts are symptomatic,[2] with epigastric pain or pain in the left hypochondrium as well as early satiety
being the most common complaints. Symptoms are generally correlated with size,[3] with the smallest generally being asymptomatic.[1]
[2]
[3]
[4]
[5]
[6]
The confirmatory diagnosis is radiological. The initial imaging test is an ultrasound
scan with pulse Doppler. CT or MRI allow better anatomical definition and surgical
preparation. It is important to carefully delineate the splenic vascularization, both
arterial and venous branches.[1]
[2]
[3]
[4]
[5]
[6]
[7]
Less aggressive therapeutic alternatives have been described for splenic cysts. Ultrasound
monitoring may be useful in simple cysts under 5 cm. Percutaneous aspiration alone
or combined with the injection of sclerosing agents, and other surgical procedures
such as marsupialization or unroofing have shown a very high recurrence rate, and
are also associated with the creation of adhesions that hinder subsequent surgery.
Therefore, their use is nowadays discouraged.[1]
[2]
[3]
[4]
[5]
[6]
[7]
Splenectomy as treatment of choice is being replaced by partial resection procedures
that preserve part of the splenic parenchyma, thus avoiding infectious complications
related to the loss of spleen's immune function. Postsplenectomy sepsis is the most
serious complication, having a prevalence of 4% of the cases with a mortality of 1.5%.[1] Hence, the preservation of splenic parenchyma is of vital importance, especially
in children. Immune function has been shown to be maintained if at least 25% of spleen's
parenchyma is preserved.[2]
[5] However, meningococcus, haemophilus, and pneumococcus vaccination is advised prior
to surgery in case total splenectomy is finally performed due to surgical complications.[8]
Partial splenectomy is currently considered to be the ideal procedure. Like the vast
majority of splenic surgical procedures, the ideal approach is minimally invasive.
The dissection of the splenic vessels and their branches continues to be the critical
step in this surgery, specially hindered by the broad anatomical variability. For
this reason, preoperative angiography is recommended to define the vascular anatomy.[2] In our patient, we performed preoperative angio-CT and used ICG fluorescence to
delineate the vascular anatomy in detail during the surgical procedure.
ICG[9] is a dye that, injected intravenously, is distributed through the bloodstream and
has complete biliary excretion without recirculation. It is an excellent vascular
marker as it quickly reaches well-vascularized tissues and washes out just as quickly
if venous return is adequate. It is harmless, cheap, and easy to use. The initial
recommended dose is 0.2 mg/kg with the possibility of a second bolus at the same dose.
ICG molecules are excited with wavelengths between 750 and 800 nm, emitting fluorescence
at 832 nm (near-infrared range) that can be detected by using special cameras built
into the laparoscopy system. The use of gray-scale cameras versus others in black
and white is recommended, since although both capture ICG fluorescence, the firsts
improve the visualization of the surgical field during the procedure and facilitate
vascular dissection.[10]
Limitations to the use of ICG are scarce. In patients with abnormal liver function
the uptake and especially, the elimination may be altered. It is contraindicated in
those allergic to iodinated contrasts or with thyroid disorders.[9]
[11]
[12]
[13]
[14]
The use of fluorescence in surgery is emerging, but experience in splenic pathology
is very limited. Kawasaki et al [15] used ICG during distal pancreatectomies with splenic preservation. Aggarwal et al[16] described a cystectomy using ICG to contrast the splenic parenchyma against the
cyst, which being avascular did not uptake contrast. Only Mizuno et al[17] present a case of partial splenectomy following a procedure similar to ours in a
50-year-old man. To this date, we have not found any published articles on the use
of ICG in procedures on splenic parenchyma in children.
We consider that the use of fluorescence provides advantages over conventional laparoscopic
partial splenectomy. It facilitates vascular dissection by defining the anatomy in
real time, it demonstrates adequate arterial perfusion of the remaining tissue, and
it increases the safety of a technically complicated procedure, without increasing
the surgical time and without notable drawbacks.
Conclusion
When surgical resection of epidermoid cysts is indicated, we believe that the ideal
technique is laparoscopic partial splenectomy, allowing the removal of the lesion
while preserving the splenic parenchyma. Dissection of the splenic hilum is the key
step during the procedure. The use of ICG-mediated fluorescence facilitates dissection
and allows the vascularization of the splenic remnant to be checked, which increases
the safety of the procedure.
To the best of our knowledge and by going through the previous publications in PubMed,
this is the first article regarding the use of fluorescence during a laparoscopic
partial splenectomy in a pediatric patient.
