Diaphragmatic Hernia after Pediatric Living Donor Liver Transplantation: An Indian Experience with Review of Literature.

AIM: Although intestinal obstruction following living donor liver transplantation (LDLT) is relatively common, diaphragmatic hernia (DH) as the attributing cause is rarely reported. The study aimed to find out the incidence, clinical presentation, and management of DH after liver transplant in pediatric patients.
MATERIALS AND METHODS: A retrospective review of all cases of pediatric liver transplants was performed. Case sheets, operation records, and investigations including radiology were studied.
RESULTS: Out of 79 cases of pediatric liver transplants, two cases of posttransplant DH were identified. The first case is a 2-year-old male child who was transplanted for progressive familial intrahepatic cholestasis, and the second one is a 4-year-old boy who underwent LDLT for hepatitis A-induced acute liver failure. The first child presented abdominal symptoms and the second one with pulmonary symptoms. The DHs were diagnosed at 132 and 70 days, respectively, posttransplant by chest radiographs and computed tomography scan. The defects were located at the posteromedial aspect of the diaphragm in both the cases and were closed by primary closure with mesh reinforcement. Both the children are doing well with no recurrence.
CONCLUSION: High index of clinical suspicion is mandated in pediatric patients after liver transplant and once the diagnosis is confirmed, urgent surgical exploration is mandatory. Copyright:

INTRODUCTION

Living donor liver transplantation (LDLT) is increasingly being performed in the pediatric population. Diaphragmatic hernia (DH) is one of the rare yet significant complications described in the literature. A high index of suspicion is of utmost importance, which can further guide early diagnosis and urgent surgical intervention before it progresses to fatal incarceration and gangrene. Although the pathophysiology is not fully established, many predisposing factors have been described such as large size grafts, ascites, pleural effusion, prolonged mechanical ventilation, previous surgery, portal hypertension, malnutrition, and diaphragmatic weakness due to thermal or mechanical injury.[1] The only treatment is the surgical reduction of the herniated bowel and repair of the defect.[2] Herein, we present our experience of two pediatric patients who developed DH after LDLT and have reviewed the literature available to date.

MATERIALS AND METHODS

Two cases of DH occurred in 79 pediatric patients transplanted. Their pretransplant records, transplant surgery records, case sheet for clinical presentation, and radiology and postsurgery records were studied. Existing literature was reviewed.

RESULTS

Case 1

A 2.5-year-old male child was diagnosed as a case of progressive familial intrahepatic cholestasis type II.[3] He underwent LDLT using left lateral segment (LLS) graft. His postoperative recovery was complicated with sepsis, upper gastrointestinal bleed, and symptomatic right pleural effusion and prolonged positive pressure ventilation for 16 days. Eventually, he recovered well and was discharged on postoperative day (POD) 51 in a satisfactory condition.

Three months later, he presented to the emergency department with complaints of increasing cough for 3 days with increased work of breathing. On evaluation, the mother informed about the low oral intake for the past 2 days though he had no frank vomiting. On Chest X-ray [Figure 1a], the right hemidiaphragm was found elevated with right-sided DH, which was confirmed on computed tomography (CT) scan [Figure 1b]. After the diagnosis of right DH was made, he underwent urgent exploration. Intraoperatively, a defect of size 4 cm × 5 cm was noted in the posteromedial aspect of the right dome of the diaphragm, just to the right of the inferior vena cava [Figure 1c and d]. Small bowel loops (distal jejunum and ileum up to ileocecal junction) were noted in the right thoracic cavity. After gentle reduction, the bowel loops were found to be healthy, with no signs of ischemia. The hernial defect was closed primarily with Prolene 3-0 sutures in a continuous fashion and was reinforced with a polytetrafluoroethylene (PTFE) mesh, and a right intercoastal drain was inserted. He made an uneventful recovery and was discharged on day 15 after surgery. He is doing well at the last follow-up (42-month post-LDLT).

Figure 1

(a) Chest X-ray showing bowel and gas bubbles in the right chest. (b) Noncontrast computed tomography showing herniated bowel loops with air–fluid levels in the right hemithorax. (c) Intraoperative picture showing small bowel loops herniating through the diaphragmatic defect (arrow). (d) Right diaphragmatic posteromedial defect

Case 2

A 4-year-old boy presented to the emergency department with jaundice for 2 months and altered sensorium for 2 days. On evaluation, a diagnosis of acute liver failure due to hepatitis A with suspected drug-induced (had consumed some ayurvedic medication) liver injury was made. He underwent emergency LDLT as he was fulfilling in King's College criteria. LDLT was done using LLS graft (graft recipient weight ratio – 1.68). He was extubated on POD 7; his postoperative course was uneventful and was discharged on day 29.

He presented to the emergency department on day 70 with pain abdomen (periumbilical and right lumbar region) for 1 day with vomiting. The initial chest radiograph showed right-sided DH which was further delineated in the CT scan and was taken up for urgent exploration [Figure 2a-c]. Intraoperatively, an 8 cm × 5 cm defect was found on the posteromedial aspect of the right hemidiaphragm. After gentle adhesiolysis, most of the small bowel, part of the ascending colon, and proximal transverse colon were reduced from the thoracic cavity. The bowel was found to be slightly edematous, but no frank signs of ischemia were noticed. The defect was primarily repaired with Prolene 1-0 suture and reinforced with PTFE mesh [Figure 2d]. His symptoms resolved and was discharged on day 10. He was doing well at the last follow-up (30-month post-LDLT). The peritransplantation clinical profile of both the patients is compared in Table 1.

Figure 2

(a) X-ray revealing bowel loops with air–fluid levels and gas bubbles in the right hemithorax. (b) Noncontrast computed tomography showing herniated bowel loops with air–fluid levels in the right hemithorax. (c) Noncontrast computed tomography showing herniated bowel loops and hypertrophied left lateral graft. (d) Intraoperative picture after reinforcement of the hernial defect with prosthetic mesh (arrow)

Table 1

Peritransplant clinical characteristics

	Patient 1	Patient 2
Preoperative
Sex	Male	Male
Age (years)	2.5	4.3
Body weight (kg)	14	21
Primary disease	PFIC-II	ALF (HAV)
Previous operation	No	No
PELD score	19	-
PHTN	Yes	No
Intraoperative
Graft type	LLS	LLS
Graft weight (g)	140	266
GRWR (%)	1.2	1.6
Total operation time (min)	520	480
Primary closure	No	No
Postoperative
Time for extubation	On table	POD 7
Use of sirolimus	No	No
Ascites	Yes	Yes
Pleural effusion	Yes	Yes
Interval between
Transplantation and DH (days)	132	70
Hernia location	Right posteromedial	Right posteromedial
Follow-up (months)	42	36

*PFIC -II: Progressive familial intrahepatic cholestasis Type II,[3] ALF: Acute liver failure, HAV: Hepatitis A virus, LLS: Left Lateral segment, POD: Postoperative day, PELD: Pediatric end-stage liver disease, PHTN: Portal hypertension, GRWR: Graft recipient weight ratio, DH: Diaphragmatic hernia

DISCUSSION

Diaphragmatic complications such as dysfunction or paralysis after LDLT in children are common, with the incidence ranging from 8% to 15%,[456] but DH is rare, with an incidence of 0.6%–3%.[127] Most are case reports, and the largest series had ten patients from King's College Hospital.[2] In our institute, we have so far encountered two DH out of the 79 pediatric transplants (2.53%). Both the cases were right sided and required immediate surgical attention.

The most common presentation is breathing difficulty, followed by features of bowel obstruction. Chest and abdominal X-ray is diagnostic, but contrast-enhanced CT is always done to delineate the defect, the contents, and the relation to any major vascular structures. Once the diagnosis is made, the management is an urgent surgical reduction and primary repair of the defect.[8] Lee et al. have described thoracoscopic repair in a case after LDLT, but laparotomy is presently the most common approach.[9] The repair can be reinforced with mesh as the diaphragm is weak and unprotected.

To form a hernia, there are three basic requirements: first is the presence of a cavity; second, increased intracavitary pressure; and third, weakened wall of the cavity. After the recipient hepatectomy and implantation of left or left lateral graft, the right upper quadrant becomes a cavity which is filled by right and transverse colons along with the small bowel.[10] Various factors that can lead to increased intra-abdominal pressure include the use of large for size grafts, paralytic ileus, and formation of large-volume ascites and prolonged mechanical ventilation.[2] The most important factor is the presence of a weak wall, which is the diaphragm in this case. Chronic liver disease in children is associated with failure to thrive, malnutrition, and sarcopenia, leading to a thinned-out diaphragm with the decreased density of muscle fibers.[11] Factors during surgery such as traumatic dissection and excessive use of energy devices can add to weakness.[12] Recipient hepatectomy in children, particularly after Kasai portoenterostomy, is a difficult undertaking. There are extensive adhesions with collaterals due to portal hypertension in between the liver and the diaphragm, which makes the use of energy devices such as diathermy and argon plasma coagulation inevitable. These all can lead to iatrogenic vascular impairment to the diaphragm.[1314] Moreover, right phrenic nerve courses along with the right hemidiaphragm and can get injured during surgery.[15] Due to the constant motion of the diaphragm, injuries take longer to heal. These all lead to herniation of abdominal contents into the thorax assisted by the negative intrathoracic pressure.

Use of immunosuppression, especially steroids and mammalian target of rapamycin (mTOR) inhibitors, has been implicated in pathogenesis. Steroids are known to cause protein depletion and delayed wound healing.[1617] mTOR inhibitors which have increased popularity in recent times have been implicated in delayed wound healing, and there are reports of spontaneous rupture of the diaphragm in patients on sirolimus.[1819] Both the patients received steroids for 3 months, but none were on mTOR inhibitors.

The prognosis has been good in literature but is a potentially life-threatening complication. Immediate intervention is warranted to prevent massive bowel loss.[2] There are no reports of recurrence in literature, but owing to the inherent weakness of the diaphragm, the patient should be followed at a timely interval.

CONCLUSION

DH should be kept in mind while dealing with intestinal obstruction or breathing difficulty in a child after LDLT using LLS grafts. We believe a foresightedness of the potential hernia occurrence, careful dissection, and proper hemostasis should be the way forward in reducing this complication.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.