Multi-institutional and multi-disciplinary care: A successfully managed aortic dissection in the third trimester of pregnancy

Abstract

Multi-disciplinary collaborative care for pregnant women with complex and emergent conditions is essential. Logistical planning, clear communication and human factor awareness are all non-clinical skills which need to be utilised in order to maximise outcomes. We describe the case of a proximal aortic dissection in the late third trimester of pregnancy diagnosed in a peripheral hospital that was transferred to a cardiothoracic centre for successful operative management 160 km away. This required the time-sensitive mobilisation and liaison of a receiving cardiothoracic, anaesthesiology and perfusionist team in conjunction with obstetric and midwifery support from an affiliated maternity hospital, as well as the national neonatal transport team. We emphasise the importance of multidisciplinary team management in complex cases and how imperative good inter-disciplinary communication is to ensure safe inter-hospital transfer.

Introduction

The multi-disciplinary team (MDT) is a crucial component to minimise the risk of maternal morbidity and mortality. ¹ Urgent maternal transfers are often discussed in the fetal interest, ² yet is also important to consider transfers in the maternal interest. It is known that inter/intra/multi-disciplinary collaboration are essential to improve patient safety, which can be difficult to achieve in urgent scenarios. ³

We present the case of an aortic dissection (AD) in the third trimester resulting in maternal and neonatal survival, owing to effective collaborative care. We discuss the essential nature of human factor awareness and effective communication in healthcare delivery.

Case

A 35-year-old Caucasian non-smoking woman attended midwifery-led care in a secondary maternity unit. She had a previous uncomplicated term vaginal delivery, a normal BMI and no medical or surgical history.

At 38 weeks and 6 days of gestation, she presented acutely with acute-onset severe non-pleuritic chest pain radiating to the epigastrium, associated with vomiting and diarrhoea. There were no other cardio-respiratory symptoms, nor concerns for a venous thromboembolic event. There were no fetal concerns. Vital signs (Table 1; showing temporal sequence of events), ECG and fetal monitoring were normal. The working diagnosis was gastroenteritis with reflux and she was admitted for treatment with a proton pump inhibitor.

Table 1.

Initial timelines and vital signs.

Time	Event	Notes	Blood pressure (mmHg)	Heart rate (per minute)	Oxygen saturations (%)	Temperature (°C)	Respiratory rate (per minute)
0610	Presentation	Admission	121/62	72	100% (room air)	36.1	18
0920	Routine observations		Left arm 111/65Right arm 120/65	65	99% (room air)	36.3	18
1430	Afternoon review	Increase in pain; prior to CT	132/63	85	99% (room air)	36.0	17
1800	Prior to transfer		150/68	94	99% (room air)	36.0	16
2030	Arrival at cardiothoracic unit	Consent and confirmation of fetal viability	150/70	90
2054	Pre-anaesthetic work
2132	Caesarean section commenced	Female infant, 3120 g
2249	Cardiothoracic procedure commenced
23:52	Extracorporeal circulation on
00:07	Cross clamp time on
03:53	Cross clamp time off	3 h 45 m cross clamp time
04:43	Extracorporeal circulation off	4 h 51 m CPB time
06:10	Surgery end	8 h 48 m total surgery time	130/50

Following recurrence of the pain, non-responsive to opioids, AD and pulmonary embolus (PE) were considered and a CTPA was organised. On examination, there was evidence of radio-radial delay, but vital signs and examination remained normal. Following CTPA, a CT aorta confirmed the diagnosis of a Stanford Type A AD (Image 1/2). ⁴ The woman remained stable, while a MDT cross-site meeting with cardiothoracic surgery, maternal medicine and obstetric anaesthesiology was conducted. The decision was made to conduct an ambulance in-utero transfer to a tertiary-level cardiothoracic centre 90 min away with a nurse, house officer and paramedic staff. The maternity and cardiothoracic units are not co-located, but an emergency protocol has been developed in conjunction with the National Neonatal Transport Team.

Figure 1.

Cross-sectional CT of aortic dissection flap.

Figure 2.

Coronal Image showing Stanford Type A AD, which continued to the renal arteries and a complex flap extending to the level of the aortic root.

At a pre-procedure MDT huddle, a plan was formulated to perform a caesarean section (CS) on arrival with high-dose opioid induction of general anaesthesia, following consultation with neonatology. Sodium citrate was not administered to avoid precipitating emesis-associated aortic rupture. Strategies to aggressively avoid uterine atony were discussed and utilised, with a target systolic blood pressure of less than 120 mmHg. These measures included avoiding nitrate administration, inhalational anaesthesia and administration of a slow bolus of 5iu oxytocin followed by placement of a prophylactic Bakri balloon due to anticipated placental bed haemorrhage secondary to systemic anticoagulation (target activated clotting time four times normal) for cardiopulmonary bypass (CPB). Following obtaining patient consent and confirming fetal viability, an uncomplicated CS was performed by two consultant obstetricians, with 900 ml blood loss. The infant was transported to the maternity hospital and discharged home on day 3 formula feeding.

Following completion of the CS, the woman was positioned supine with 15 degree hip flexion and pneumatic compression stockings for the duration of the surgery to allow vaginal access and observation for postpartum haemorrhage. Following median sternotomy and pericardial opening, CPB was instigated with indirect innominate artery and right atrial cannulation. Systemic cooling was instituted to a core temperature of 26°C. An intra-operative transoesophageal echocardiogram revealed a severely incompetent aortic valve, due to annular dilatation. Using selective cerebral reperfusion, an Evita plus stent graft was implanted into the proximal descending aorta, followed by aortic arch reconstruction with a Quadra limb haemoshield graft. During systemic rewarming, an aortic root reconstruction was performed with a David-type valve-sparing aortic root using a 30 mm Valsalva graft. The woman was then de-aired, re-warmed, re-perfused and weaned off CPB with routine chest closure with a blood loss of 1300 ml.

Post-procedure, the woman was transferred to intensive care, with blood product replacement (fibrinogen, red cell concentrate, fresh frozen plasma, platelets and 600 ml cell salvage); there was no evidence of disseminated intravascular coagulation. Extubation was performed on day 2, and de-escalation occurred to cardiothoracic high dependency. Initial residual unilateral upper limb weakness was investigated with a negative CT brain and this resolved within 48 h. A line-related left brachial vein thrombus was managed with three months of warfarin treatment. A right-sided pleural effusion detected on post-operative CT on day 2 was managed with a thoracentesis. Prior to discharge on day 20 post-operatively, clear advice was given regarding medication compliance, heavy lifting, avoiding conception and “red-flag” symptoms. She remains stable on therapeutic anticoagulation at eight weeks post-operatively, with a long-acting reversible contraceptive device being placed at 12 weeks post-operatively, coinciding with a follow-up CT aorta to ensure graft stability.

Discussion

Maternal morbidity and mortality report continually identify cardiac disease as the leading cause of maternal death. ¹ AD contributes to 11% of deaths, ¹ the condition having reported mortality rates of 24%. ⁵ , ⁶ However, in cases of a proximal AD complicated by pericardial effusion, an immediate mortality rate 40% is described, with the rate of death increasing at 1 and 3% per hour, and 70% within 24 h. ⁷ The importance of prompt recognition and MDT management of AD is continually noted. The familiarity of the local obstetric team with the MBRRACE report aided a rapid diagnosis and co-ordination of care.

Effective team function in obstetrics is essential to optimise patient care. ⁸ Clear and assertive communication is essential and improves patient safety, ⁹ with human factor awareness and MDT discussions shown to improve patient outcomes. ⁸ , ⁹ Clinical dilemmas such as the optimal site of delivery, risk of maternal/fetal death, emergency assembly of MDTs and benefit of transfer were discussed with each clinicians’ expertise taken into consideration, showing situational awareness of the human and non-human resources available. A number of team members were required to work in unfamiliar environments, bringing personnel and equipment challenges to care. Structured briefings, such as the MDT ‘huddle’, as employed in this case, have been shown to improve care and reduce intraoperative errors. ¹⁰

Good teamwork is essential to deliver safe and effective care in all clinical settings, particularly in critically ill obstetric women. ⁸ This case highlights the importance of MDT management in complex cases and how imperative good inter-disciplinary communication is to ensure safe inter-hospital transfer.