Current and Future Developments in Surgery

Major Upper Gastrointestinal (UGI) surgery encompasses a wide range of potential surgical procedures, many of which pose substantial challenges to the anaesthetist caring for the patient in the peri-operative period. Pre-anaesthetic assessment and optimisation of the patient are critical. The objectives of anaesthesia are to render the patient unaware of the surgical stimulus, to provide favourable intraoperative conditions for surgery, and to improve patient experience and outcome, particularly in cardiorespiratory function and post-operative analgesia. The specific points to consider in oesophago-gastric surgery include the position of incisions, the duration of surgery, the multi-site nature of the operations and the premorbid condition of the patients considered for surgery. Whilst there is no substitute for experience and frequent exposure to these procedures, there are a number of specific anaesthetic issues which merit expert consideration. This chapter will explore a number of facets of patient care: from pre-operative assessment to anaesthetic technique and finally, post-operative care. Due to the high propensity of post-operative complications, particularly infections, which contribute to additional morbidity specific to oesophago-gastric surgery; a section is included on infection and antibiotic prophylaxis. In addition, multi-modal analgesia will be considered as the site of surgery for many of these patients can impact on post-operative respiration and can contribute to post-operative respiratory infections.

Adult critical care is an important, high profile and high-cost area of modern healthcare provision. Postoperative management after elective oesophago-gastric surgery for cancer has a huge bearing on mortality and morbidity. Assessment of the impact of surgery requires reliable tools that assess the morbidity and mortality risks, including the severity of the surgical insult. These tools have evolved over the last century but are not patient specific. In general, intensive care provides level 3 care to patients requiring mechanical ventilation where as a high dependency unit (level 2 care), has a vital role in patients requiring support for a single failing organ system. Post-operative monitoring, analgesia and nutrition are the main tenets of critical care. Tissue injury secondary to surgical trauma produces profound changes to all body systems and triggers the stress response. Although considerable effort has gone into defining the stress response over the past century, very little advance has been made to negate or modify the stress response or its effects on the surgical patient. The surgical insult also produces inherent changes to ventilatory mechanics. The combination triggers single or multi-organ failure. The main systems affected in this cascade are the respiratory, cardiovascular and renal systems. Hepatic and coagulation systems failure tend to be late and multi-factorial. Critical care units have evolved in the multifaceted management of these failing systems.

Oesophageal disorders can impact locally on food delivery to the stomach while gastric disorders can interfere with reservoir function and chemical digestion. These restrictive disorders prevent anabolism and contribute to catabolism in order to maintain function. However, many oesophago-gastric disorders can impact on the energy balance through their systemic effects such as sepsis or cancer cachexia as two notable examples. These are catabolic disorders and despite adequate intake malnutrition is the end result. Malnutrition is prevalent in most patients with oesophago-gastric disorders particularly in patients with cancers of the oesophagus or stomach. In addition, the effects of therapeutic modalities delivered to the oesophagus or stomach such as surgery, chemo and radiotherapy can also influence a catabolic state either directly or indirectly. The local, systemic and therapeutic effects on energy balance have to be addressed by a thorough screening, assessment, appropriate therapy and continuous monitoring of nutritional status. All patients with reduced oral intake and / or weight loss as a result of mechanical or functional obstruction in the oesophagus or stomach should be screened and referred for dietetic assessment and management if appropriate. The overall goal of dietetic therapy in oesophago-gastric disorders is to address the energy imbalance, restore the energy requirements and improve symptoms in order to maintain function and survival.

The oesophagus and stomach present a wide spectrum of benign and neoplastic conditions. Understanding the pathology of these conditions has always been important to the surgical management of these diseases. The advent of modern molecular pathological techniques has greatly expanded our knowledge of the underlying pathogenesis of these conditions and now directly affects practice. The integration of this new knowledge with standard histopathological techniques presents new challenges to the pathologists and surgeon alike. This chapter discusses benign and malignant pathology of the oesophagus and stomach, with repeated emphasis on new knowledge where these influence practice. By far, the commonest conditions affecting the oesophagus and stomach are benign. However, these conditions can impact heavily on affected individuals. Although relatively rare, cancers carry a huge burden on the individual and society. Specific management and prognosis for these conditions are dependent on accurate diagnosis, which is the realm of pathology. In this regard, the patient presentation, clinical and diagnostic findings together with chemical pathology (Biochemistry), where appropriate, are essential in guiding the pathologist to apply sophisticated pathological essays that clinch the diagnosis. In some circumstances, pathology is also important in identifying the aetiology, pathophysiology and malignant potential of some conditions.

The contribution of radiological investigations in oesophago-gastric disorders has traditionally been diagnostic and for staging of malignant disease. However, radiological techniques have evolved in recent years into interventional procedures in the management of gastrointestinal bleeding, porto-systemic shunt formation, biopsies, stent placement and in the management of post-surgical complications. Indeed, interventional radiology cover is one of the criteria stipulated in guidelines for a quality oesophago-gastric service. The evolution of radiological modalities of investigation and staging has brought a larger choice of techniques and more sophisticated equipment, which have impacted, on clinical practice. This has resulted in the requirement for super specialisation amongst radiologists in order to keep abreast of contemporary techniques. “G-I radiologists” have become adept with the nuances of specialist interpretation of radiographic images of the gastro-intestinal tract and have embraced advanced techniques of image acquisition and interrogation to provide maximal information. In addition, some have developed specialised interventional procedures for diagnostic and therapeutic purposes.

The prime function of the oesophagus is the transfer of ingested food from the pharynx to the stomach. This is facilitated by its structure. The oesophagus traverses the posterior mediastinum to emerge through the diaphragmatic hiatus into the abdomen. The structure, function and disorders of the diaphragm directly affect oesophageal function. Diaphragmatic hiatal herniae, affect food transport through the oesophagus and is one of the causes of gastro-oesophageal reflux. Chronic reflux contributes to oesophagitis and peptic strictures. Congenital, traction and pulsion oesophageal diverticula can also affect food transport across the oesophagus and be responsible for dysphagia. Muscular and mucosal rings, cysts and duplications can also affect oesophageal function and cause disordered swallowing. Traumatic and spontaneous oesophageal injuries and perforations can be life threatening and the emphasis is on early diagnosis, prompt resuscitation and antibiotic cover followed by definitive surgical treatment. Oesophageal variceal haemorrhage can be catastrophic and with significant mortality. It tends to occur in patients with liver disease. Urgent resuscitation, evaluation and appropriate management are all too essential. Patients should be enlisted in surveillance and therapeutic programs to prevent further bleeds. A number of endoscopic and surgical techniques have evolved to manage all these benign disorders of the oesophagus.

Pathological gastro-oesophageal reflux is multifactorial chronic disorder with increasing prevalence. Incompetence of the physiological anti-reflux mechanisms at the gastro-oesophageal junction results in this reflux and the cardinal symptoms are heartburn and regurgitation as well as a host of extra-oesophageal manifestations. Severe chronic GORD results in prolonged oesophageal acid exposure and to the development erosive esophagitis, deep ulcers, strictures and Barrett's oesophagus. The goal of treatment for GORD is to control symptom control, to heal any oesophagitis and to improve the quality of life. Acid suppression represents the mainstay of medical treatment for GORD. Proton pump inhibitors provide symptomatic relief and healing of erosive oesophagitis in over 80% of patients. Surgical intervention aims to provide a curative reconstruction of the anti-reflux barrier at the GOJ and should be considered in patients with continuing or drug-refractory GORD. Anti-reflux surgery has shown greater resolution of reflux symptoms and oesophagitis compared to medical therapy. Currently laparoscopic total or partial fundoplication is the gold standard for surgical intervention. The most common post-operative complications are gaseous bloating, dysphagia and diarrhoea. A number of novel therapies, such as the LINX and Esophyx, have shown promise in achieving good symptomatic relief by correcting pathological reflux and possessing a better side-effect profile than surgical fundoplication.

Barrett’s oesophagus (BE) is a metaplastic change of the oesophageal mucosa from squamous to columnar mucosa (with intestinal metaplasia). The condition is recognized endoscopically as pink salmon extensions in the lower oesophagus. It is an acquired condition arising as a result of chronic gastro-oesophageal reflux disease (GERD) and is regarded as a premalignant condition of the oesophagus leading to oesophageal adenocarcinoma. Patients typically present with symptomatic GERD, but the condition also occurs in asymptomatic individuals. The diagnosis of BE is made endoscopically and confirmed histologically. BE is a common problem with prevalence rates ranging from 5% to 15% in the general population. The condition is associated with an increased risk of oesophageal adenocarcinoma (OAC), approximately 0.5% per patient per year. This translates to an estimated lifetime risk of cancer development of 5-8%. There is growing acceptance of the metaplasia, dysplasia, adenocarcinoma sequence in the development of adenocarcinoma of the oesophagus. A small but significant proportion of patients with Barrett’s metaplasia will develop dysplastic change. Those who progress from low-grade dysplasia (LGD) to high-grade dysplasia (HGD), have a 10% annual risk of developing adenocarcinoma and the 5-year survival for these patients is of the order of 12%. Treatment is dependent upon the degree of dysplasia, and for cancer, the depth of invasion and the presence of lymphovascular invasion. Endoscopic surveillance is warranted for those with low-grade dysplasia (LGD), followed by endoscopic mucosal resection and ablative therapy in those with HGD limited to the mucosa. Surgical resection is reserved for those with established submucosal disease and a high likelihood of lymphovascular invasion.