Perioperative Care of the Surgical Patient: Reconstructive Surgery

Applied Surgical, Pathologic, and Physiologic Concepts

General

The resection of tumors may cause large aesthetically and functionally unacceptable defects. Similarly, adjuvant therapies may leave functional tissue impairment or chronic nonhealing wounds requiring excision and reconstruction. Reconstructive surgery aims to obliterate dead space, provide structural support for remaining tissues, ensure adequate wound closure and healing, and maintain an aesthetically acceptable appearance.

Flap surgery has improved markedly over the last few decades, with success rates of greater than 95% reported. This is the result of enhanced microsurgical techniques and an evolving appreciation for perioperative optimization. In this setting of progress, however, anesthetic perioperative management of free flap surgery is varied, reflecting the paucity of high-level evidence guiding best practice. Continued critical review of current flap surgery literature and extrapolation from other surgical fields is imperative to improve outcomes.

Surgical Concepts

Autologous flap reconstructions can be categorized as “pedicled” or “free.” A pedicled flap remains partially connected to the donor site via an intact vascular pedicle. The pedicle is at most 5 cm long, limiting reconstruction to local defects. A latissimus dorsi flap, used in breast reconstruction, is a commonly used example. Free flaps are completely detached from the donor site and constitute any combination of skin, fat, fascia, muscle, bone, nerves, bowel, or omentum. These flaps are used for more distant reconstructions.

There are several distinct phases during free flap surgery. In the initial phase, donor tissue and its vascular pedicle (artery and vein) are dissected or raised . The clamping and division of the pedicle leads to cessation of blood flow to the donor tissue. This primary ischemic phase varies in duration but typically lasts between 60 and 90 min. Donor blood vessels are then anastomosed to distant recipient blood vessels using microsurgical techniques. Restoration of blood flow and reversal of the effects of anaerobic metabolism occur during this reperfusion phase . This phase, also called the secondary ischemic phase , is susceptible to ischemic reperfusion injury.

There is a single surgical anastomosis of each vascular pedicle, making free flaps extremely vulnerable to hypoperfusion and venous congestion. Common causes of impaired blood flow include arterial or venous thrombosis at the anastomotic site, arterial vasospasm, and insufficient venous drainage. Ruptured anastomosis with hematoma formation, tightly applied dressings, and poorly positioned equipment can cause external compression on the pedicle. Some vascular pedicles are prone to kinking or stretching with changes in patient positioning. Prolonged ischemic times and flap hypoperfusion secondary to low cardiac output states may exacerbate the secondary ischemic injury.

Pathologic Concepts Associated With Free Flap Complications: The Endothelial Glycocalyx, Inflammation, and Ischemic Reperfusion Injury

The endothelial glycocalyx (EG) is a gel-like structure, lining the intraluminal surface of the endothelial cells of all blood vessels and organs. It has several well-defined functions and plays an integral role in blood vessel wall integrity. It is a delicate structure and can rapidly change under certain metabolic and inflammatory conditions. Lifestyle risk factors (obesity, smoking), adjuvant treatments (radiotherapy), and chronic pathologic conditions (hyperglycemia, renal and cardiovascular disease) predisposes this delicate structure to pathologic insults. ^, Acute degradation of the EG has also been observed in patients undergoing major surgery, leading to capillary leak, platelet aggregation, and loss of vascular responsiveness. In the perioperative setting, this can result in tissue edema, detrimental to wound healing, acute kidney injury, increased risk of venous thromboembolism (VTE), and lability of arterial pressure.

Flap surgery has the potential to cause major systemic inflammatory perturbation in the postoperative period. Large, multisite tissue disruption, and ischemic reperfusion injury, seen within the flap microvasculature, can cause disruption to the composition and structure of the fragile EG. Degradation leads to loss of the barrier function between blood components and the underlying vessel wall. The adhesion of circulating immune cells and activation of several proinflammatory pathways cause further disruption and dysfunction within this layer. These pathologic processes may progress and lead to localized effects (flap complications, organ dysfunction) or systemic effects (systemic inflammatory response syndrome, coagulopathies). ^,

Following ischemic reperfusion injury, deactivation of some of the protective antioxidative enzymes within the EG leads to oxidative stress. This includes the deactivation of superoxide, a natural antioxidant active within the EG, which keeps reactive oxygen species and free radicals in equilibrium under physiologic conditions. It also has a role in the functionality and release of other antioxidants such as nitric oxide. Nitric oxide causes localized vasodilation in response to increases in shear stress (increased blood flow). Therefore a reduction in its levels will result in loss of microvascular autoregulation, possibly compromising reperfusion.

In addition a degraded and exposed endothelium is vulnerable to platelet adhesion and activation of the coagulation cascade with subsequent thrombus propagation. As previously mentioned, venous and arterial thrombosis can be detrimental to flap viability. Venous thrombosis is more prevalent than arterial thrombosis.

Blood flow and oxygen delivery to free flap tissue may become impaired with a rise in local interstitial tissue pressure. Several factors predispose free flap tissues to this pathologic process.

In its physiologic state, the EG is a protein-rich layer that contributes significantly to intravascular oncotic pressure. According to the revised Starling equation, this oncotic pressure is an important factor opposing fluid filtration across the endothelial layer into the interstitium. With degradation and loss of the protein content of the EG, the layer becomes more permeable with increased filtration of fluid and other intravascular molecules into the interstitium. This is commonly seen in inflammatory states and contributes to a decrease in the half-life of intravenous (IV) crystalloids and colloids alike. ^, ^, Reabsorption of interstitial fluid relies exclusively on intact lymphatic flow and not on reabsorption from the venous capillaries, as previously stated by the original Starling equation. Transplanted free flap tissues are devoid of an intact lymphatic system and therefore vulnerable to any increase in fluid accumulation.

Perioperative fluid management is known to have a profound impact upon the integrity of the glycocalyx : acute hypervolemic hemodilution causes EG injury by mechanical stress on the vascular wall and via the secretion of atrial natriuretic peptide. This peptide is secreted in response to atrial stretch, which can be a consequence of rapidly infused IV fluid. It also increases microvascular permeability permitting fluid and colloid extravasation into the interstitium. Studies have shown that when 5% human albumin or 6% hydroxyethyl starch (HES) is infused into a normovolemic patient, 60% of the colloid rapidly extravasates into the interstitium.

The combination of the above-mentioned pathologic processes are likely reasons why multiple studies specific to flap surgery have linked high volumes of IV fluids with worse surgical (wound healing, flap failure) and medical (pulmonary congestion) outcomes.

Relevant to cancer surgery, the EG layer also acts as a barrier to prevent interaction between the ligands on circulating tumor cells and the adhesion receptors on endothelial cells. Following surgical tissue damage, inflammatory activation of procoagulant and prothrombotic pathways may cause clot formation in the microvasculature and platelet adhesion onto circulating tumor cells. This pathologic process has two consequences. The platelet coat on the circulating tumor cells decreases detection by host defense mechanisms such as natural killer cells. In addition, microvascular occlusion promotes adhesion of these cells onto the degraded endothelium, enabling migration across this layer. In effect, inflammatory mediators may contribute to colonization and lymphatic spread, promoting metastasis. ^,

Hyperoxia causes increased levels of reactive oxygen species with increased tissue destruction after ischemic reperfusion injury. Studies looking at outcomes after ischemic events such as cerebral vascular accidents and myocardial infarction have linked hyperoxia with expansion of infarct size and worse outcomes. ^, Intraoperative inspired oxygen concentrations should be carefully titrated to the arterial partial pressure of oxygen (Pao ₂ ) deemed appropriate for the clinical setting. Perioperative measures to improve pulmonary function should be employed to reduce the need for and duration of oxygen therapy.

In conclusion, seemingly safe routine perioperative therapies such as IV fluid and oxygen therapy can potentially cause harm by exacerbating the degradation of the EG seen during surgery. Possible strategies to reduce EG breakdown are discussed in the section on Strategies for Hemodynamic Optimization .

Physiology of Flap Perfusion and Relevant Perioperative Factors

The blood supply and drainage of free flap tissue can be complex. One cannot assume that an isolated understanding of the physiologic laws governing blood flow is sufficient. Instead, there is a dynamic and complex interplay between the pathologic and other physiologic processes requiring more complex consideration.

The Hagen-Poiseuille law is frequently used to describe the determinants of flap perfusion/flow:

Q = ∆Pπr ⁴ /8ηl

where Q (flow) is directly proportional to ∆P (perfusion pressure) and the fourth power of r (radius), and inversely proportional to η (viscosity) and l (length of the tube).

The radius of the blood vessels is an important determinant of blood flow but is not constant and homogeneous within the flap. This can be due to a number of independent factors. Irregularities in the endothelial layer close to the surgical anastomosis will invariably cause turbulence in blood flow and a decrease in the radius of the blood vessel. Reperfusion injury causes localized vasospasm, as well as shedding of the endothelial cells and glycocalyx with resultant microthrombus formation and propagation. Surgical manipulation and cold exposure of the vascular pedicle may also cause vasospasm. In addition, acute denervation of pedicle blood vessels causes an attenuated vasoconstrictor response to systemic catecholamines. As a result, normal physiologic laws do not hold true, and medical interventions aimed at altering the radius of the blood vessels might not reliably lead to improvements of blood flow.

The Hagen-Poiseuille law states that cardiac output is directly related to a pressure differential across a vascular bed. This is one of the reasons why routine intraoperative blood pressure (macrovascular) monitoring is used as a surrogate for tissue perfusion (microvascular). This has several limitations, as follows.

Cardiac output or blood flow is also dependent on systemic vascular resistance, as seen in the following equation:

Cardiac output = (mean arterial pressure – right atrial pressure)/systemic vascular resistance

An increase in peripheral resistance seen after the administration of a vasopressor agent may lead to an increase in blood pressure but a decrease in flow or cardiac output. This may compromise the free flap tissues. Additionally, the physiologic response to a hypovolemic state is to preserve perfusion pressure to vital organs at the expense of nonvital organs (skin and fat in the free flap). As a consequence, a predetermined target blood pressure may not reflect adequate flap perfusion and may be falsely reassuring.

Under physiologic conditions, there is an expectation that microvascular perfusion will improve in parallel with macrovascular optimization. This is referred to as hemodynamic coherence. Loss of hemodynamic coherence has been described in states of infection, inflammation, and reperfusion injury. The resultant impaired function of the endothelium and the EG leads to microvascular obstruction, vasoconstriction, and interstitial edema, despite correction of the macrovascular parameters. Regardless, optimization of the macrovascular parameters should be primarily achieved prior to targeting the microcirculation.

Noninvasive, intraoperative optical techniques may be used in real time to assess the microcirculation of free flap tissue. Novel techniques under investigation include optical coherence tomography (vessel density and decorrelation), side-stream darkfield microscopy (velocity, microvascular flow index, total vessel density, perfused vessel density), laser speckle contrast imaging (perfusion units), and fluorescence imaging (time constant and time to peak measured). Once integrated into standard practice, these bedside measurements may allow for dynamic assessment of medical interventions to optimize macrovascular parameters and flap tissue perfusion.

Strategies for Hemodynamic Optimization

Surgical intervention leads to an increase in oxygen consumption and metabolic demand. The aim of hemodynamic optimization is to reduce tissue hypoperfusion and meet the increased metabolic demands of the tissues. These measures should be instituted in the early preoperative period and may be continued postoperatively to overcome potential oxygen debt.

Preoperative Carbohydrate Drinks

Adequate preoperative hydration starts with minimization of fasting times. Complex carbohydrate drinks up to 2 h prior to surgery are safe and improve metabolism, and decrease insulin resistance and postoperative nausea and vomiting (PONV). Postoperatively, early transition to oral hydration should be encouraged, and IV fluids should be discontinued once the patient is hemodynamically stable.

Goal-Directed Therapy

Perioperative administration of IV fluid plays a pivotal role in patient management and has a direct impact on outcomes. The principles of IV fluid administration are to maintain central normovolemia for optimal cellular perfusion and to avoid interstitial edema from salt and water excess. The utilization of goal-directed therapy (GDT) allows for tailored IV fluid, inotropic, and vasoactive agent administration. Contemporary minimally invasive devices derive measurements such as cardiac index, stroke volume, or stroke volume variation from pulse power analysis, pulse contour analysis, and esophageal Doppler monitoring. Medical therapy is titrated according to these explicit targets that reflect end-organ blood flow.

Although a large number of randomized trials have been conducted investigating the effect of GDT on perioperative outcomes, concerns exist regarding the quality of studies, with the majority being single-center trials with methodological limitations and risk of bias. A systematic review and meta-analysis of 31 studies carried out by the Cochrane group in 2013 found no difference in mortality between patients receiving GDT compared with controls, but reported a significant reduction in overall complication rate and a reduced rate of renal and respiratory failure, wound infection, and length of hospital stay (LOHS). Two multicenter studies with larger participant numbers investigating the effects of GDT have been published since this review. ^, Addition of the OPTIMISE study, a multicenter randomized trial of high-risk patients undergoing major gastrointestinal surgery, to the original meta-analysis confirmed an overall reduction in complication rates across trials when GDT was utilized. These findings were reproduced in the FEDORA trial, where patients were randomized to GDT with optimization of circulating volume prior to vasopressor use versus standard care : significantly fewer complications were observed in the GDT group, and again a reduction in LOHS was observed. Finally, a recent meta-analysis of 95 randomized controlled trials comparing GDT versus standard hemodynamic care showed a reduction in mortality and complications, although a high risk of bias and poor methodological quality was again present in a number of included studies.

Studies specific to autologous breast flap surgery comparing standard care with GDT in combination with an Enhanced Recovery After Surgery (ERAS) protocol have shown a reduction in LOHS with no difference in complications. The average amount of intraoperative fluids used in the GDT group averaged 3.85 L versus 5.5 L in the preimplementation group.

Central line placement in free flap surgery is not indicated unless prolonged vasoactive infusions are anticipated. Central venous pressure monitoring does not improve hemodynamic optimization and has been associated with worse outcomes and complications from line placement. ^,

Intraoperative oliguria defined as urine output of less than 0.5 mL/kg/h has not been correlated with acute kidney injury in noncardiac surgery. Oliguria should not be interpreted in isolation. Careful consideration of the patient’s comorbidities, the clinical context, and other hemodynamic parameters should be used as a guide for fluid resuscitation.

Choice of Intravenous Fluid Therapy

Consensus has been reached within the anesthesia community that perioperative IV fluid therapy to meet maintenance fluid requirements should consist of the infusion of balanced crystalloid solutions, with the avoidance of 0.9% saline. Administration of saline results in hyperchloremic metabolic acidosis and has been associated with renal dysfunction, increased LOHS, and increased mortality in patients undergoing noncardiac surgery. There is insufficient evidence to preferentially direct the choice of balanced crystalloid specifically for reconstructive surgery. Rate of infusion of maintenance crystalloid is pertinent in the perioperative management of these patients, primarily in the avoidance of iatrogenic fluid overload and the resultant effects on EG disruption previously discussed. A recent systematic review recommended intraoperative volume replacement during autologous tissue transfer surgery to be maintained between 3.5 and 6.0 mL/kg/h.

Ongoing debate continues regarding whether HES colloids are safe to administer in the perioperative period for volume therapy. Significant concerns regarding the use of HES and the risk of acute kidney injury in critically unwell patients have resulted in cautious perioperative use, although evidence from recent trials is challenging this mindset. A systematic review and meta-analysis of the impact of perioperative administration of HES reported no difference in risk of acute kidney injury in the elective surgical setting with colloid use, although the authors noted that trials were typically small and underpowered. Results from two larger randomized controlled trials recently published confirm these findings: GDT consisting of colloid versus crystalloid boluses revealed no increased risk of renal toxicity with colloid administration, with one study reporting an increase in disability-free survival in the treatment group. ^,

A paucity of studies examining the effect of IV colloid infusion specifically during autologous reconstruction surgery exists. A single study compared the effects of HES and 5% albumin solution for volume replacement therapy during major reconstructive head and neck (HN) surgery, with both colloids effectively maintaining physiologic variables in the perioperative period. No difference in outcome was observed until an excess of 30 mL/kg HES occurred over a 24-h period, which was associated with coagulopathy and increased risk of allogenic blood transfusion. Allogenic blood transfusion has been associated with increased mortality and surgical site infection following free flap reconstructive surgery for oral cancer.

Historically, the rheological properties of dextran, a complex branched glucan polysaccharide, were thought to confer benefit in reconstructive flap surgery for prophylaxis of microvascular thrombosis. This ideology has since been disproved, with a significant increase in risk of flap failure with dextran use observed in high-risk oncologic patients, no observed benefit in flap survival, and an association with higher incidence of systemic complications, including unwanted bleeding, acute renal failure, allergic reactions, and cerebral edema.

Vasoactive and Inotropic Drugs

Utilization of vasopressor support in an attempt to improve end-organ perfusion and reduce perioperative complications requires consideration of not only the resultant mean arterial pressure achieved but also the context in which the vasopressor is used with regard to both circulating intravascular volume and adequacy of flow. Vasopressor use in the setting of hypovolemia may be detrimental to tissue and microcirculatory blood flow, and optimization of circulating volume prior to vasopressor use should be considered in the perioperative period.

It is known that sustained periods of intraoperative hypotension should be avoided due to their association with adverse outcomes: myocardial injury, acute kidney injury, and increased risk of mortality. A recent consensus statement from the perioperative quality initiative stated that even brief durations of systolic blood pressures <100 mmHg or mean arterial pressures <60–70 mmHg are harmful during noncardiac surgery. A novel trial reported that individualized targeting of systolic blood pressure within 10% of baseline value significantly reduced the risk of organ dysfunction compared with standard care.

The use of vasoactive and inotropic drugs during flap surgery remains contentious. Concerns exist that these drugs may cause anastomotic and flap microvascular vasoconstriction, limiting flap tissue perfusion. Multiple studies have demonstrated no link between perioperative vasoactive/inotropic agent use and flap complications, including flap failure. ^, The acute denervation of pedicle blood vessels changes their response upon exposure to vasoconstrictor agents. Specifically, they have an attenuated response; hence vasoconstriction may not occur at these sites despite the administration of a vasoconstrictor such as noradrenaline. This is in contrast to the vasoconstriction seen in innervated skin blood vessels. Another contributory explanation is the anticipated increase in the cardiac index with appropriate inotropic drug administration in normovolemic patients. This may result in increased flap perfusion.

With respect to choice of agent, noradrenaline increases free flap skin blood flow in hypotensive patients in a dose-dependent manner. Dobutamine increases free flap blood flow to a lesser extent without increasing mean arterial blood pressure. The use of dobutamine may be limited by tachycardia, especially in patients predisposed to ischemic heart disease. Adrenaline and dopexamine both decrease free flap skin blood flow and are not suitable agents for flap surgery. Milrinone, an inodilator, does not improve free flap outcomes and is associated with increased intraoperative use of vasopressor support.

Therapies Targeting the Endothelial Glycocalyx

Therapeutic approaches aimed to protect or restore the EG against injury represent a promising direction in clinical medicine. Strategies to reduce oxidative stress and inflammation may include the perioperative use of glucocorticoids, human plasma, plasma augmented with albumin, and IV lidocaine. There is currently insufficient evidence supporting the routine integration of these modalities into clinical practice.

Perioperative Considerations for Microvascular Free Flap Transfer Procedures

Patient outcomes are broadly determined by an interplay of three major variables: the extent of the surgical insult, the patient’s risk factors as determined by acute and chronic medical disease, and the quality of the perioperative care they receive.

The extent of tissue injury during flap reconstruction can be considerable. There may be numerous surgical sites, including the area of cancer ablation surgery, and one or more donor sites for flap harvesting. This may result in significant metabolic and physiologic derangements. Anticipating these disturbances is important for anesthetic planning and potential patient optimization.

Patient risk factors, as determined by their comorbidities and diseases of lifestyle, should be identified and modified where possible. There is emerging evidence that risk factors, such as smoking and hyperglycemia, affect the EG and predispose patients to inflammatory processes in the perioperative period. In addition, cancer burden and neoadjuvant therapies may further contribute to adverse outcomes. Adequate optimization might not be possible in the setting of time-pressured cancer surgery.

Perioperative care is ideally provided by a multidisciplinary team. The implementation of perioperative care bundles reduces variation in practice and aims to address modifiable factors leading to incremental and cumulative improvements in outcomes. ^, (See sections on Autologous Breast Reconstruction and Enhanced Recovery After Surgery for Autologous Breast Reconstruction .)

Perioperative Considerations

Identification and Optimization of Risk Factors Associated With Poor Flap Outcomes

Smoking and Nicotine Replacement Therapy

Smoking is an independent risk factor for complications in reconstructive procedures. It has been linked to deep surgical site infections, incisional dehiscence, and a higher return to theater rates. ^, Smoking causes harm via a number of pathways. Carbon monoxide alters the oxygen-carrying capacity of hemoglobin. Nicotine causes vasoconstriction and promotes the formation of microthrombi via catecholamine and thromboxane A2 release, respectively. Hydrogen cyanide impairs the function of enzymes implicated in cell metabolism. Combined, these factors contribute to impaired wound healing. Each week of abstinence allows reversal of some of these processes, with a significant benefit demonstrated at approximately 4 weeks. Preclinical animal studies link nicotine replacement therapy with wound healing complications; however, it is unclear if this translates into worse outcomes for reconstructive procedures. While nicotine replacement therapy is preferred to active smoking, complete cessation of both is preferable in the perioperative period.

Diabetes Mellitus and HbA1c

There is little research specifically assessing the impact of diabetes in patients undergoing reconstructive surgery. In the field of reconstructive breast surgery, studies have demonstrated a greater incidence of adverse outcomes in diabetic patients undergoing autologous breast reconstruction. This has not been demonstrated with implant-based breast reconstruction.

Current guidelines have been extrapolated from diabetic patients undergoing other major surgeries, cardiac and noncardiac, in which there is a demonstrable increase in both morbidity and mortality. Good preoperative glycemic control, as determined by HbA1c concentrations, is associated with a lower incidence of systemic and surgical complications, decreased mortality, and shorter LOHS.

Radiotherapy

Preoperative radiation to the recipient site causes fibrosis to the vasculature and surrounding tissue with an increased risk of flap-related complications. Complications include poor wound healing, fat necrosis, and flap loss. ^, Radiotherapy to the HN region is also a risk factor for a difficult airway.

Anemia

Anemia is defined as a hemoglobin level <13 g/dL for men and <12 g/dL for women. It is diagnosed in almost 50% of cancer patients during the course of their disease and is an independent risk factor for increased 30-day morbidity and mortality in patients undergoing major noncardiac surgery. In the setting of oncosurgery, the causes of anemia include impaired production of red blood cells (systemic inflammation, chemotherapy-related bone marrow suppression, and renal tubular toxicity with decreased erythropoietin production) and iron deficiency anemia (occult bleeding, decreased iron absorption).

Studies specifically assessing preoperative anemia in autologous reconstruction surgery did not show an association with surgical complications, including flap thrombosis or flap loss. Postoperative hemoglobin levels <10 g/dL were associated with increased LOHS and medical complications, but did not increase flap-related complications. ^, Intraoperative blood transfusion correlated with postoperative medical complications (mostly respiratory related), but again not with surgical complications.

Anterolateral thigh (ALT) free flaps were associated with more blood loss and have higher rates of intraoperative blood transfusion when compared with radial forearm free flaps (RFFF) and fibular free flaps.

Specific management of preoperative anemia involves a multidisciplinary approach targeting the likely causes of anemia. Proven therapeutic interventions include diet modification and IV iron therapy. Oral iron supplementation has reduced efficacy and does not meet the time constraints of planned surgery. Treatment of anemia with recombinant erythropoietin has been associated with symptomatic venous thrombosis in the setting of chronic inflammation in cancer patients. It is unclear if this translates into a risk for flap thrombosis. The modest benefit in treating anemia with erythropoietin in the short term may not justify this theoretical risk for flap thrombosis. Expert opinion should be sought.

In conclusion, preoperative anemia should be optimized to minimize the risk of transfusion-related medical complications. Anemia and perioperative blood transfusions are not independently associated with flap complications and therefore should not influence the consideration for blood transfusion.

Malnutrition

The prevalence of malnutrition in cancer surgery is reportedly as high as 47%. Causation can be multifactorial: secondary to the inflammatory or neoplastic disease, or due to altered metabolic state, poor access to nutrition, or gastrointestinal tract dysfunction. The Nutrition Risk Screening tool-2002 (NRS-2002) and the Subjective Global Assessment (SGA) tool are currently the most validated nutrition screening tools in the surgical population. The NRS-2002 is a good predictor of postoperative complications and can be used to predict mortality, morbidity, and LOHS.

Key elements of nutritional optimization involve provision of protein and micronutrient supplementation to increase muscle mass and support metabolic functions. There is currently no consensus on the duration of nutritional support. However, a 5- to 7-day duration of preoperative nutrition therapy is reported to reduce postoperative morbidity by 50%. The European Society for Clinical Nutrition and Metabolism guidelines advocate a 7- to 14-day supplementation period for severely malnourished patients.

Autologous Breast Reconstruction

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