Combined Pre- and Postnatal Minimally InvasiveApproach to Complicated Pulmonary SequestrationsMartina Ichino1 Francesco Macchini1 Anna Morandi1 Nicola Persico2,3 Isabella Fabietti2

Andrea Zanini1 Ernesto Leva1

1Department of Pediatric Surgery, Fondazione IRCCS Ca' GrandaOspedale Maggiore Policlinico di Milano, Milano, Lombardia, Italy

2Department of Obstetrics and Gynecology “L. Mangiagalli”, FetalMedicine and Surgery Service, Fondazione IRCCS Ca’ GrandaOspedale Maggiore Policlinico di Milano, Milano, Lombardia, Italy

3Department of Clinical Science and Community Health, Universitàdegli Studi di Milano, Milano, Lombardia, Italy

Eur J Pediatr Surg Rep 2020;8:e62–e67.

Address for correspondence Martina Ichino, MD, Department ofPediatric Surgery, La Fondazione IRCCS Ca’ Granda OspedaleMaggiore di Milano Policlinico, Milano 20122, Lombardia, Italy(e-mail: martina.ichino@outlook.it).

Keywords

► pulmonarysequestration

► fetal therapy► thoracoscopy► laser coagulation► congenital lung

malformation

Abstract Pulmonary sequestration (PS) is mostly asymptomatic but there is a proportion offetuses that develop hydrops, leading to fetal or neonatal death. Fetal treatments areavailable, but postnatal management of the residual lesions is not uniformly defined.We present two cases of combined pre- and postnatal minimally invasive approach tocomplicated extra-lobar PS.Patient 1 presented with complicated PS at 31 weeks of gestation. Ultrasound-guidedlaser coagulation of the anomalous artery was successful. The patient was bornasymptomatic at 38 weeks. Neonatal magnetic resonance imaging (MRI) showed aresidual mass, confirmed by computed tomography (CT) at 6 months. No systemicartery was described, but perfusion was present. We decided for thoracoscopicresection. A residual artery was identified and sealed. Patient 2 presented withcomplicated PS at 25 weeks of gestation, underwent laser coagulation of theanomalous artery and was born asymptomatic at 38 weeks. Neonatal MRI showedpersistence of the lesion, confirmed by CT scan at 4 months. We proceeded withthoracoscopic resection. A residual vessel was ligated. The patients 1 and 2 are now 24and 21 months old, respectively, and healthy.Prenatal treatment of complicated PS is a life-saving procedure.Postnatal thoracoscopic resection of the residual lesion is feasible and safe; we believeit is the best course of treatment to grant the complete excision of the malformation.

Importance for a Pediatric Surgeon

Pulmonarysequestrations canoccasionallypresentwithprenatal complication, correlated tohigh incidenceof fetal orneonataldeath. The availability of fetal therapies is changing the outcome of these complicated lesions, but post-natal treatment of theresidualmalformation remains debated.Wepresentour experience of a combinedpre- andpostnatal approach to complicatedpulmonary sequestration.

receivedNovember 22, 2019acceptedMay 16, 2020

DOI https://doi.org/10.1055/s-0040-1713901.ISSN 2194-7619.

© 2020 Georg Thieme Verlag KGStuttgart · New York

Case ReportTHIEME

e62

Published online: 2020-09-18

Introduction

Pulmonary sequestration (PS) is the second most commonprenatally diagnosed congenital pulmonary airway malforma-tion.1–3 It consists of a mass of nonfunctioning pulmonaryparenchyma, disconnected from the bronchial tree, and receiv-ing an anomalous systemic arterial blood supply. PS can beclassified as intralobar PS (IPS), when it is included in the lobarpleura andusually drains in the pulmonary venous system, andas extralobar PS (EPS), when the mass has its own pleura andsystemic venous drainage.2 Most of the PSs are asymptomaticduring pregnancy but, in a minority of cases, PS can becomplicated by pleural effusion, mediastinal shift, and eventu-ally hydrops fetalis which is reported in 6.8 to 20%1,4 ofprenatally diagnosed PS cases. Hydrops is a harbinger of fetaldemiseorneonatal death if left untreated1,5–7; overallmortalityfor nonimmune hydrops fetalis is reported between 76 and78%.8,9 Given the poor prognosis of PS complicated by hydrops,prenatal treatmentwith open fetal surgeryhas beenattempted,but it results in high incidence of maternal complications andelevated risk of preterm labor.10 With the progression of mini-mally invasivefetal surgical techniques, various treatmentshavebeen developed to increase the chance of survival of thesefetuses and reduce impact on the mother. As with everytechnical progress, new questions come into light, thenew approaches need verification and patients care must beadjusted accordingly. Data concerning the outcomes of prenataltreatment of PS aremostly representedbycase reports and caseseries,1,11–18 all reporting a very high rate of survival of prena-tally treated fetuses compared with the poor prognosis of thefetuses affected by complicated PS that are left untreated. Themost popular techniques are fetal thoracentesis, thoracoamni-otic shunts, and ultrasound-guided laser ablation or sclerother-apy of the anomalous feeding vessel.1,11 Standardizedindications for fetal intervention inprenatally diagnosed PS stillneed tobedefined,hydrops fetalis seemsuniversallyconsideredas an indication for fetal intervention, but case series also reportintervention in case of severe pleural effusion.1,5,14 Thoracent-esis and thoracoamniotic shunts are symptomatic treatmentsthat reduce the hydrothorax and consequently the mediastinalshift, reducing the compression on the mediastinal vessels andtherefore the risk of fetal hydrops. Thoracentesis is, however, atemporary solution. Fluid often reaccumulates in the pleuralspace with possible need of multiple procedures. Cavorettoet al11 report reaccumulation of the fluid in six out of sixreviewed cases. Survival rate for patients with PS that weretreatedwith thoracentesis is reported as83%.5Thoracoamnioticshunt positioning could theoretically avoid the need for multi-ple thoracentesis; however, reaccumulation of fluid wasreported by Cavoretto et al in 2 out of 17 reviewed cases,11

and thoracoamniotic shunts may dislocate with possibleincreased morbidity.19 A survival rate of 92% is reported byWitlox et al5 after thoracoamniotic shunting for PS. The laserablationand thesclerotherapyof thefeeding vesselhavetheaimof reducing the blood sequestration from fetal circulation andthe PS mass itself, thus treating the disease and reversing itscomplications.12 Sclerotherapyhas been reported as effective infouroutof four reviewedcases11witha survival rateof75%5and

laserablationwaseffective in10outof10reviewedcases11witha survival rate of 100%.5 To the best of our knowledge, only onedeath after laser treatment for PS has been reported later on.15

Moreover,Witlox et al5 report a lower rate of respiratory failureatbirth incases treatedwithvascular laserablationascomparedwith cases that underwent palliative treatments. Althoughcomplications, such as damage to adjacent organs, uterine orfetal bleeding, and placental abruption14 must be expected, tothe best of our knowledge, they have not been reported.

Given the rarity of prenatally complicated PS, these are stillpreliminary data and thebest pre- andpostnatalmanagementof this malformation remains to be confirmed. The ablation ofthe anomalous vessel seems a safe and effective approach andis the technique adopted at our center. It is considered in thepresence of a considerable risk of intrauterine demise orpreterm delivery, such as in case of hydrops, tense polyhy-dramnios and significant Doppler abnormalities.

The management of the residual masses after birth is notuniformly defined at present: some surgeons remove theeventual remnant after birth,11 others don’t.14 We presenttwo cases of EPS that were treated with fetal laser coagula-tion of the anomalous vessel and were subsequently thor-acoscopically removed with elective surgery after birth.

Case Report

Case 1Case 1 is amale fetus that presentedwith left inferior pulmonarymalformation consistent with EPS at 31 weeks of gestation.Obstetric ultrasound showed severe unilateral hydrothorax oc-cupying>50% of the thoracic cavity, with right mediastinal shiftand subcutaneous edema. An echogenic mass in the inferiorportion of the left fetal lung, measuring 45 mm� 37mm� 38mm, was observed (►Fig. 1) and Power Dopplerdemonstrated blood supply through amain feeding vessel. Basedon thesefindings, the option of fetal intervention by ultrasound-guided laser coagulation of the anomalous vessel was discussedwith the parents and, after informed consent, the procedurewasperformed at 31 3/7 weeks of gestation. Briefly, after administra-tion of fetal intramuscular anesthesia andmaternal local analge-sia, a 17-G needle (Cook Medical, Bloomington, Indianapolis,IndianaUnitedStates)was introducedunderultrasoundguidancethrough the fetal thorax to reach a distance of few millimetersfrom the feeding vessel. Subsequently, a 400-µm diameter diodelaser fiber (Dornier MedTech GmbH, Wessling, Germany) wasadvanced through the sheath of the needle. Laser energy with apower of 15 to 20 Watts was applied for few seconds twice tothrice to ensure complete cessation of blood flow. Aspiration of50mL of thoracic fluid was performed. The complete procedurelasted 30minutes, and there were no intraoperative complica-tions.Serial follow-upultrasoundexaminationsshowedanormalfetal growth and the Doppler and a progressive improvement ofthe pleural effusion until complete resolution by 34 weeks ofgestation. The size of the EPS was significantly reduced to 21mm� 19 mm� 18mm at 38 weeks.

The newborn was delivered vaginally at 38 5/7 weeks ofgestation with a birth weight of 3,295 g and he was asymp-tomatic throughout the postnatal period. Given the prenatal

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diagnosis of PS, despite prenatal treatment, the patient wasmanaged according to our internal protocol for pulmonaryairways malformations. The protocol foresees chest X-ray atbirth to exclude possible acute complications (pneumothoraxand massive mediastinal shift), chest magnetic resonanceimaging (MRI) in spontaneous sleep in the first month of lifeto confirmdiagnosiswithoutadditional radiation, andwithoutneed for sedation, and preoperative chest computed tomogra-phy (CT) scan with contrast. The chest X-ray showed normalradiological findings and a neonatalMRI in spontaneous sleepwas performed and showed persistence of a solid mass in theleft costofrenic angle with diameters of 17 mm� 11mm� 20mm, with a suspicion of a cystic component. Noanomalous vessel was visualized by MRI. Due to the persis-tence of the malformation, a clinical follow-up was started.Echocardiography ruled-out anatomical or functional heartdisease. A preoperative chest CT scan with contrast wasplanned and performed at 6 months of age. It showed themass with 12 mm� 9mm dimension and no visible afferentvessel, butperfusion inside themasswaspresent.Decisionwasmade to proceed with surgery. At 7 months of age the patientunderwent thoracoscopy, he was positioned in right lateraldecubitus and a 3-mm trocar was inserted under the tip of thescapula. Capnothorax was created at 5mmHg at 1L/min. Twoadditional trocarswere inserted on the anterior axillary line: a3-mm one in the third to fourth intercostal space and a 5-mmone in thefifth to sixth. At the inspection of the thoracic cavity,numerous adhesions were evident between the visceral andthe parietal pleura (►Fig. 2). After lysis of the adhesions withJust-Right Sealing System (3mm), the PS was identified andconfirmed as extralobar. It presented strong adhesions to theleft inferior lobe. An apparently patent feeding vessel comingfrom the thoracic aorta was identified as well. The vessel wasclosed proximally with a Hem-o-lock clip and sealed distallywith Just-Right Sealing System and divided. Histology con-firmed the PS.

The postoperative coursewas uneventful with no need formechanical ventilation. Chest drain was removed on post-

operative day 2 and the patient was discharged on thepostoperative day 3. The patient is now 24-month old, hepresents a regular growth and is in good health with norespiratory symptoms.

Case 2The second case is amale fetuswithdiagnosis of left inferior PSat 25 weeks of gestation. Ultrasonographic follow-up evi-denced progressive worsening of mediastinal shift and unilat-eral hydrothorax (►Fig. 3), developmentofascites, andcardiacfailure. The fetal MRI confirmed a 30 mm� 37 mm� 44mmmass with an anomalous systemic vessel of 2.6mm of diame-ter originating from the aorta at the thoracoabdominal pas-sage, consistent with an EPS. Concomitant hydrothorax withmaximum width of 16mm was described, as well as rightmediastinal shift and mild ascites. Given the presence ofhydrops, a fetal treatment with ultrasound-guided laser coag-ulationof the anomalous vesselwas offered, and after parentalconsent the procedure was performed at 26 1/7 weeks ofgestation. The procedure was performed using the sametechnique as described for case 1 with a total duration of24minutes. No intraoperative or postoperative complicationswere observed, and there was progressive resolution of fetalhydrops by 30 weeks of gestation. A repeat fetal MRI per-formed at 30 4/7 weeks of GA showed a reduction in size of themalformation (22 mm� 24 mm� 19mm), no visible vesselsand only minimal residual hydrothorax. No further complica-tions presented during pregnancy.

The newborn was delivered vaginally, asymptomatic, at 385/7 weeks of gestation with a birth weight of 4,070 g. Chest X-ray at birth was normal. Neonatal chest MRI showed persis-tence of a 19 mm� 19 mm� 21mm mass in the left supra-diaphragmatic paravertebral region. An echocardiographyruled-out anatomical or functional heart disease so a clinicalfollow-up was started. A chest CT scan was performed at4 months of age. The malformation was described of 16mm� 12mm, adherent to the costovertebral pleura andwith adhesions to the diaphragmatic pleura. No systemic

Fig. 1 Prenatal images of patient described as case 1. Sagittal view of the echogenic mass in the inferior portion of the left fetal lung (A) andtransverse view showing severe unilateral hydrothorax (B).

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vessel was visualized. Decision was made to proceed withsurgery. At 5 months of age the patient underwent thoraco-scopic resectionof themasswith thesame techniqueas for theprevious case. Again, at the inspection of the pleural cavitysevere adhesions were evident. The sequestration was con-firmed as extralobar and was strongly attached to the leftinferior lobe. A residual systemic vessel was identified, closedwith a Hem-o-lock clip and divided with Just-Right 5-mmstapler, given the vessel dimension (►Fig. 4). Histology con-firmed a PS with necrotic-calcified areas of neoangiogenesis.No mechanical ventilation was required postoperatively. The

postoperative coursewas characterized bymild bleeding fromthe chest drain treated conservatively. The chest drain wasremoved on the postoperative day 3 and the patient wasdischarged on the postoperative day 4.

The patient is now 21-month oldwith regular growth andno respiratory symptoms.

Discussion

The high mortality of prenatally complicated PS is wellknown.1,5–9,20 Nowadays, the availability of fetal surgery

Fig. 3 Prenatal images of patient described as case 2. Transverse view of the fetal thorax illustrating a giant solid lung mass with massivemediastinal shift (A) and sagittal view of the thorax showing a systemic feeding artery arising from the aorta (B).

Fig. 2 Presence of numerous adhesions between the visceral and the parietal pleura in the patient described as case 1.

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has opened a variety of treatment opportunities that haschanged the outcome of these severe forms. Ultrasound-guided laser ablation of the anomalous vessel seems to grantthemost effective and lasting results,5 and it can be saidwithenough confidence that it is safe and effective in the shortterm, and that the benefits of this procedure outweigh itspossible complications such as damage to adjacent organs,uterine or fetal bleeding, placental abruption, and prematurebirth.14However, the postnatal management of these lesionsremains to be debated. While it is evident that prenatallytreated PS that show symptoms at birth need to be removed,the optimal treatment course of the asymptomatic residuallesions is not clear.

Oepkeset al12 in2007reportedacaseof lasercoagulationoftheanomalousarteryofaPS. Theprocedurewassuccessfulandlead to an asymptomatic newborn. Nonetheless, a CT scan at1.5 years of age showed persistence of the sequestration withsystemic blood supply. The parents declined surgery becauseof the absence of symptoms. A second report of this procedurewas made by Ruano et al,13 the procedurewas uncomplicatedand reversed the fetal hydrops, but 7 weeks after the proce-dure, blood flow reappeared in the anomalous vessel. Thepatientunderwent lobectomyonthe15thdayof lifebecauseofonset of respiratory distress. Cavoretto et al11 presented aseries ofeight patientswith complete resolution in threewhilefive patients required postnatal sequestrectomy for persis-tence of the lesion at imaging. Cruz-Martinez et al14 reportedanother series of eight cases describing a complete interrup-tion of vascular flow with one procedure in five cases, whilethree cases required a second laser treatment. Postnatal CT

scan showed a small residual non perfused mass in all cases.Given the absence of vascular flow, sequestrectomy was notperformed. Mallmann et al18 reported five cases of laserablation for EPS. Three cases required one intervention, andin two cases, the procedure was repeated to obtain completeflow interruption. In four cases complete regression wasobserved and one case required sequestrectomy after birth.

In bothour cases, the fetal procedurewassuccessful, leadingto regressionof fetal symptomsand to a subsequently unevent-ful pregnancy. Both patientswere asymptomatic at birth, but aresidual mass was present. In one case, the mass presentedsigns of revascularization at CTscan. In the other case, themasspersisted without signs of reperfusion, but presenting fibrousconnection to the pleura and the diaphragm. In both cases, webelieved the indication for sequestrectomy was appropriategiven the persistence of the lesion and their characteristics.Moreover, given the experience of our center with thoraco-scopic surgery, the possibility to offer the sequestrectomywitha minimally invasive approach granted a reduced surgicalimpact.Thepresenceofpleural adhesionsasa resultofprenataltreatment, did not impede theminimally invasive approach.Aswe evidenced intraoperatively, even if the postnatal CT didn’tshow the anomalous systemic vessel, the vascular structurewas still present. As we previously discussed, the revasculari-zation of the anomalous vessel after laser coagulation has beendescribed.12–14 At present, it is not possible to predict theincidence of revascularization of the sequestration for the lackof long-term data. Given the absence of follow-up studies,especially regarding the cases treated conservatively afterbirth, it is not possible to strongly support one choice over

Fig. 4 Residual systemic vessel in the patient described as case 2, closed with Hem-o-Lock clip before division with Just-Right 5-mm stapler.

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the other. Nonetheless, we believe that if the PS persists afterbirth, it should be treated as a PSwithout prenatal treatment,and therefore should undergo elective thoracoscopic resectionto avoid the development of symptoms. Especially if it showssigns of perfusion, if it seems intralobar, and therefore with apossibility of hybrid lesion, or if it causes compression on thehealthy lung. Thoracoscopic sequestrectomy for PS, whenperformed by experienced surgeons, is a safe minimally inva-siveprocedureeven in thepresenceofadhesions following fetaltreatment. The discussed elements lead us to favor, at present,postnatal surgery after prenatal laser coagulation. Moreover,we think that, in case of conservative approach, an adequateclinical and radiological follow-up has to be warranted toevidence a possible recurrence. In such cases, thoracic MRIcan be considered as a primary imaging technique for thefollow-up to reduce the radiation impact.21

Conclusion

Prenatal treatment of complicated PS is a life-saving proce-dure. It results in regression of symptoms, but not alwaysdisappearance, of the lesion. Postnatal thoracoscopic resec-tion of the residual lesion is feasible and safe in trainedhands; we believe that it is the best course of treatment togrant the complete excision of themalformation, thus avoid-ing the risk of future complications.

Conflict of InterestAll authors have no financial disclosures.

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