You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


Introduction
============

Different surgical techniques for hybrid procedure for hypoplastic left heart syndrome (HLHS) have being described \[[@B1]\]. Taking into account local fibrosis or tissue friability during second stage operation, the possibility of aortic arch obstruction related to stent deployment and surgical difficulty in management of distal ductal stented area must be considered \[[@B2]-[@B5]\].

Caldarone \[[@B6]\] reported an alternative solution to palliate HLHS, with pulmonary artery (PA) to innominate artery shunt, associated to bilateral pulmonary artery banding (PAB), patent ductus arteriosus stenting and atrioseptostomy, not avoiding future events related to the stent.

The purpose of this case report is to describe a new technique to palliate HLHS with banding PA branches, without patent ductus arteriosus stent, but with a double shunt from PA to ascending and descending aorta by combined thoracotomies. This new technique provides adequate flow to aortic arch and descending aorta, avoiding patent ductus arteriosus stenting, and, eventually, future problems with patent ductus arteriosus stent removing.

Case report
===========

The operation is performed by 2 combined approaches: 1. median sternotomy and 2. left thoracotomy. Cardiopulmonary Bypass is not used. By median sternotomy, right and left PAB with 3.0 mm Polytetrafluoroethylene bands are performed.

After heparin infusion (2 mg/kg), a reverse Blalock-Taussig shunt with 4 mm Polytetrafluoroethylene graft is performed from proximal PA to inomminate artery. After that, a 7 mm Polytetrafluoroethylene graft is anastomosed in the left side of proximal PA, directed towards left pleura (Figure [1](#F1){ref-type="fig"}).

![**Double shunts from pulmonary trunk**.](1749-8090-6-146-1){#F1}

Distal edge of the graft is closed and placed inside left pleura. Chest is drained and closed. The child is then repositioned and left 4^th^intercostal space is opened; the Polytetrafluoroethylene graft is identified and anastomosed with descending aorta (Figure [2](#F2){ref-type="fig"}).

![**By left thoracotomy, graft is anastomosed to descending aorta**.](1749-8090-6-146-2){#F2}

A 3.5 kg white female, 30 days old, was admitted; prostaglandin E-1 was initiated, after diagnosis, with 22 days of life. The echocardiogram showed 1.4 mm ascending aorta, small Atrial Septal Defect (3.0 mm), mild tricuspid regurgitation and RV systolic dysfunction.

Bilateral PAB and double shunting procedure with 4.0 and 7.0 mm Polytetrafluoroethylene graft were performed, as described before (Figure [3A](#F3){ref-type="fig"} and [3B](#F3){ref-type="fig"}). Oxygen saturation after PAB rised from 82% to 89%. Atrial Septal Defect stenting was required in 1^st^PO day, due to restrictive Atrial Septal Defect. Warfarin anticoagulation was initiated.

![**Illustrations of shunts**. A - Double shunts from pulmonary trunk to innominate artery and towards left pleural space. B - Shunt anastomosed to descending aorta by left thoracotomy.](1749-8090-6-146-3){#F3}

The child experimented a sudden cardiac arrest in 75^th^PO day. The echo after recover showed important right ventricular dysfunction and 4.0 mm shunt occluded. Retrograde flow to aortic arch from 7.0 mm shunt was demonstrated.

Five months after first operation, a Norwood/Glenn operation was performed; pre-operative mild/moderate right ventricular dysfunction was demonstrated. Cardiopulmonary Bypass was installed, using 2 arterial lines: one with the shunt from PA to descending aorta and the second by a new shunt to innominate artery. Flow was maintained all time during Cardiopulmonary Bypass. Pulmonary artery bands were removed, with no residual stenosis; patent ductus arteriosus was disconnected and reconstruction of aortic arch was performed using a left pulmonary artery homograft, with no ascending aorta reimplantation. Atrial Septal Defect stent was removed and Glenn anastomosis was permormed.

Good hemodynamic recovery was observed (SO~2~88%), and SVC/PA pressure ranged from 16 to 18 mmHg. Initial evolution was good, with tracheal extubation in 8^th^post operatory day, being reentubated in the next day. Pulmonary infection was detected and, despite antibiotic treatment, the child died in 12^th^post operatory day, after systemic infectious complications.

Comment
=======

Unsuccessful series of hybrid procedures in HLHS previously performed in our institution stimulated us to find a different solution for a surgical proposition that we considered very attractive. We had problems in stent deployment in 1 case, and, in another one, technical problems and tissue tearing with bleeding during patent ductus arteriosus dissection.

Considering the need of ascending and descending aorta flow, we developed the idea to create another shunt from main PA to descending aorta, added to a reverse shunt, as described by Caldarone \[[@B6]\].

We considered the use of two thoracotomies an additional risk of morbidity. In this case, no problems associated with the two approaches were observed, encouraging us to move forward with this idea.

The 4 mm shunt occlusion was really a problem; it\'s difficult to assume, but the cardiac arrest probably had a relation with the event, causing right ventricular dysfunction and change of directions and timing in the second stage of the treatment. We considered that some competition between the two shunts could be a cause of flow reduction and shunt occlusion. We suggest that the double shunting technique could be more indicated in cases of associated aortic coarctation or severe aortic arch hypoplasia.

Second stage operation was performed, not in the best right ventricular function, but the operation was considered successful. Our initial idea that absence of patent ductus arteriosus stent should facilitate the surgical procedure was confirmed. No problems during patent ductus arteriosus dissection were observed. Cannulation of both shunts as arterial lines, despite the possible presence of debris inside the shunts, must be considered an attractive option.

Unfavorable evolution of the patient was observed, but we consider that infection, and not the technique, was the most responsible for the outcome.

Consent
=======

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests
===================

The authors declare that they have no competing interests.

Authors\' contributions
=======================

MBJ wrote the draft of the manuscript and obtained the written consent. All authors performed the literature review. MBJ and VOC participated in the manuscript writing. MBJ was the chief surgeon and responsible for finalization of the manuscript. All authors have read and approved the final manuscript.

Acknowledgements
================

This report was supported by the Brazilian Ministry of Health (Ministério da Saúde do Brasil).