Latex-Infused Porcine Abdominal Model: A Novel Microsurgery Simulator for Deep Inferior Epigastric Perforator Dissection.

BACKGROUND: Perforator dissection and flap elevation are routinely performed for microsurgical reconstruction; however, there is a steep learning curve to mastering these technical skills. Though live porcine models have been utilized as a microsurgical training model, there are significant drawbacks that limit their use, including cost, limited ability for repetition, and obstacles associated with animal care. Here we describe the creation of a novel perforator dissection model using latex augmented non-living porcine abdominal walls. We provide anatomic measurements that demonstrate valuable similarities and differences to human anatomy to maximize microsurgical trainee practice. METHODS: Six latex-infused porcine abdomens were dissected based on the deep cranial epigastric artery (DCEA). Dissection was centered over the abdominal wall mid-segment between the second and fourth nipple line. Dissection steps included exposure of lateral and medial row perforators, incision of anterior rectus sheath with perforator dissection, and dissection of DCEA pedicle. DCEA pedicle and perforator measurements were compared with deep inferior epigastric artery (DIEA) data in the literature. RESULTS: An average of seven perforators were consistently identified within each flap. Assembly of the model was performed quickly and allowed for two training sessions per specimen. Porcine abdominal walls demonstrate similar DCEA pedicle (2.6 ± 0.21 mm) and perforator (1.0 ± 0.18 mm) size compared with a human's DIEA (2.7 ± 0.27 mm, 1.1 ± 0.85 mm). CONCLUSION: The latex-infused porcine abdominal model is a novel, realistic simulation for perforator dissection practice for microsurgical trainees. Impact on resident comfort and confidence within a microsurgical training course is forthcoming.

Preoperative visualization of midline-crossing subcutaneous arteries in transverse abdominal flaps using photoacoustic tomography.

BACKGROUND: Photoacoustic tomography is a noninvasive vascular imaging modality that uses near-infrared pulsed laser light and ultrasound to visualize vessels. We previously demonstrated the utility of photoacoustic tomography for anterolateral thigh flap surgery involving body-attachable vascular mapping sheets. However, it was not possible to obtain clear separate images of arteries and veins. In this study, we tried to visualize subcutaneous arteries that cross the midline of the abdomen, since these arteries are known to be important for obtaining large perfusion areas in transverse abdominal flaps. METHODS: Four patients scheduled to undergo breast reconstruction with abdominal flaps were examined. Photoacoustic tomography was performed preoperatively. The tentative arteries and veins were traced according to the S-factor, an approximate hemoglobin oxygen saturation parameter calculated using 2 laser excitation wavelengths (756 and 797 nm). Intraoperatively, arterial-phase indocyanine green (ICG) angiography was performed after abdominal flap elevation. Images of vessels speculated to be arteries by preoperative photoacoustic tomography were merged with those of intraoperative ICG angiography and analyzed in an 8 × 4-cm2 area below the umbilical region. RESULTS: The S-factor was used to visualize the midline-crossing subcutaneous arteries in all 4 patients. A matching analysis compared preoperative tentative arteries according to photoacoustic tomography with ICG angiography results in the 8 × 4-cm2 area below the umbilical region and indicated a 71.3-82.1% match (average: 76.9% match). CONCLUSIONS: This study demonstrates that the S-factor, a noninvasive, label-free imaging modality, can be used to successfully visualize subcutaneous arteries. This information can aid in selecting perforators for abdominal flap surgery.

Vascular Anatomy and Variations of the Anterior Abdominal Wall - Significance in Abdominal Surgery.

Detailed knowledge of the human anatomy is an integral part of every surgical procedure. The majority of surgery related complications are due to a failure to possess appropriate knowledge of human anatomy. However, surgeons pay less attention of the anatomy of the anterior abdominal wall. It is composed of nine abdominal layers, which are composed of fascias, muscles, nerves, and vessels. Many superficial and deep vessels and their anastomoses supply the anterior abdominal wall. Moreover, anatomical variations of these vessels are often presented. Intraoperative and postoperative complications associated with entry and closure of the anterior abdominal wall could compromise the best surgical procedure. Therefore, sound knowledge of the vascular anatomy of the anterior abdominal wall is fundamental and a prerequisite to having a favourable quality of patient care. The purpose of the present article is to describe and delineate the vascular anatomy and variations of the anterior abdominal wall and its application in abdominal surgery. Consequently, the most types of abdominal incisions and laparoscopic accesses will be discussed. Furthermore, the possibility of vessels injury related to different types of incisions and accesses will be outlined in detail. Morphological characteristics and distribution pattern of the vascular system of the anterior abdominal wall is illustrated by using figures either from open surgery, different types of imaging modalities or embalmed cadaveric dissections. Oblique skin incisions in the upper or lower abdomen such as McBurney, Chevron and Kocher are not the topic of the present article.

Analysis of 461 Consecutive Patients' Donor Site Morbidity following Abdominal Tissue-Based Breast Reconstruction without Fascia Reinforcement Graft.

Despite the popularity of breast reconstruction with abdominal flap, the integrity of the abdominal wall gets compromised after the operation. To decrease donor site morbidity, researchers have developed various inlay or onlay graft materials. However, the indications of use are unclear and dependent on the subjective decision of the surgeons. In this study, we have investigated donor site morbidities in breast reconstruction with free abdominal flap surgery in which graft materials were not used. We reviewed 461 consecutive cases for the preoperative characteristics of patients, intraoperative details, and postoperative donor site complications from May 2013 to March 2019. While 386 patients underwent deep inferior epigastric perforators (83.7%), muscle sparing type 2 transverse rectus abdominis musculocutaneous flaps were performed in 75 patients (16.3%). Bilateral dissection of the pedicle was performed in 162 patients, compared to unilateral dissection in 299 patients. The mean follow-up duration was 22.7 months. The overall complication rate in the donor site was 7.2%. The flap height was significantly associated with the overall complication. While majority of them were delayed wound healing (n = 28, 6.1%), there were four cases of hematoma (0.9%). There were two cases of bulging (0.4%), which occurred in patients receiving bipedicle dissection; however, there was no case of hernia. Conclusions. Breast reconstruction with an abdominal free flap can be safely performed without fascia reinforcement graft even with bilateral dissection of the pedicle. With complete preservation of fascia and zigzag fascial incision, a low incidence of abdominal bulging can be obtained even with bilateral harvesting of the flap.

A vein-viewing application enabled detecting abdominal wall varices related to the presence of non-treated gastroesophageal varices: a cross-sectional study.

BACKGROUND: Gastroesophageal varices (GOV) are a life-threatening complication in chronic liver disease. A method for non-invasively predicting GOV is crucial for management. This study aimed to determine whether a vein-viewing application can detect abdominal wall varices (AWV) and elucidate the relationship between AWV and GOV. METHODS: One-hundred patients with chronic liver diseases were prospectively enrolled. All the patients underwent esophagogastroduodenoscopy within three months of the enrollment. Unmanipulated images (UI) and vein-weighted images (VWI) were taken for assessing AWV by a vein-viewing application on iPhone. Two doctors independently evaluated both image types. We defined the grading of both UI and AWV as grade 0 (non-detectable), grade 1 (slightly detectable), and grade 2 (distinct). RESULTS: The causes of liver diseases among the 71 men and 29 women (median age, 70.5 yr) included Hepatitis B (n = 19), Hepatitis C (n = 21), alcoholism (n = 33), primary biliary cholangitis (n = 3), autoimmune hepatitis (n = 4) and others (n = 20). GOV was indicated in 60 patients, and half of them had not been treated previously (non-treated). VWI could significantly visualize AWV than UI (72% vs. 24%, p = 0.0005). The presence of cirrhosis (chronic hepatitis vs. cirrhosis = 64.6% vs. 91.4%, p = 0.004) and GOV (52.3% vs. 74.3%, p = 0.032) were significantly higher in the VWI-AWV grade 2 group. Multivariate analysis demonstrated that VWI-AWV grade 2 was an independent factor related to the presence of non-treated GOV [OR = 3.05 (1.24-7.53), p = 0.016]. CONCLUSIONS: The vein-viewing application non-invasively detected AWV related to the presence of cirrhosis and GOV, and VWI-AWV grade 2 was an independent factor related to the presence of non-treated GOV.

Diagnostic complexity of rifampicin-induced coagulopathy in a patient with spontaneous muscle bleeding: A case report.

INTRODUCTION: Rifampicin is currently used to treat various bacterial infections, with the most significant application in the treatment of tuberculosis. Dose-independent side effects of the drug can lead to the development of various coagulation disorders, among which disseminated intravascular coagulation is the most dangerous. The mechanism of coagulopathy itself is multifactorial, but it is thought to be mediated by an immune response (formation of antigen-antibody complexes) and consequent damage to platelets and the vascular endothelium. PATIENT CONCERNS: A 66-year-old woman, with numerous comorbidities including chronic renal failure, condition after implantation of a permanent pacemaker, and a positive blood culture for Staphylococcus aureus, presented with spontaneous bleeding in the muscle wall, and in the clinical picture of hemorrhagic shock. DIAGNOSIS: Knowing the multifactorial mechanism of rifampicin-induced coagulopathy, possible factors were considered, such as infections, comorbidities, drug use and drug-drug interactions, pathological laboratory parameters, and coagulograms. Clinical presentation of abdominal pain and intra-abdominal mass, with laboratory verification of prolonged activated partial thromboplastin time and computed tomography-proven hematoma suspected of acute bleeding, redirects clinical suspicion of drug-induced coagulopathy. INTERVENTIONS: By discontinuing rifapicin and administering vitamin K and fresh frozen plasma, normalization of laboratory coagulation parameters was achieved. Bleeding from the muscle wall required correction of acute anemia with red cell concentrates, surgical intervention, and additional antibiotic therapy for secondary infection of the operative wound. OUTCOMES: At the end of 6 weeks of antibiotic (antistaphylococcal) therapy (due to the basic suspicion of possible infectious endocarditis), the normalization of inflammatory parameters occurred with a sterile control blood culture and a normal coagulogram. CONCLUSION: Clinicians should be aware of the possible side effects of the administered drugs, especially taking into account the overall clinical picture of a patient, including comorbidities and possible drug interactions.

Arterial anatomy of the anterior abdominal wall: Ultrasound evaluation as a real-time guide to percutaneous instrumentation.

INTRODUCTION: Instrumenting the anterior abdominal wall carries a potential for vascular trauma. We previously assessed the presence, position, and size of the anterior abdominal wall superior and inferior (deep) epigastric arteries with computed tomography (CT). We now present a study using ultrasound (US) assessment of these arteries, to evaluate its use for real time guidance of percutaneous procedures involving the rectus sheath. MATERIALS AND METHODS: Twenty-four participants (mean age 67.9 ± 9 years, 15 M:9 F [62:38%]) were assessed with US at three axial planes on the anterior abdominal wall: transpyloric plane (TPP), umbilicus, and anterior superior iliac spine (ASIS). RESULTS: An artery was visible least frequently at the TPP (62.5 - 45.8%), compared with the umbilicus (95.8-100%) and ASIS (100%), on the left, χ2 (2) = 20.571; p < .001, and right, χ2 (2) = 27.842; p < .001, with a moderate strength association (Cramer's V = 0.535 [left] and 0.622 [right]). Arteries were most commonly observed within the rectus abdominis muscle at the level of the TPP and umbilicus, but posterior to the muscle at the level of the ASIS (95.8-100%). As with the CT study, the inferior epigastric artery was observed to be larger in diameter, start more laterally, and move medially as it coursed superiorly. CONCLUSIONS: These data corroborate our previous results and suggest that the safest level to instrument the rectus sheath (with respect to vascular anatomy) is at the TPP. Such information may be particularly relevant to anesthetists performing rectus sheath block and surgeons during laparoscopic port insertion.

Preoperative computed tomography assessment for a deep inferior epigastric perforator (DIEP) flap: a new easy technique from the Bologna experience.

BACKGROUND: Deep inferior epigastric perforator (DIEP) flap reconstruction is the gold standard reconstructive technique for women undergoing breast cancer surgery. A preoperative computed tomography angiography (CTA)-dedicated protocol and 3D reconstructions are mandatory for correct surgical planning. PURPOSE: To evaluate the diagnostic performance of a new preoperative CTA protocol and a new reconstruction method in the assessment of DIEP technique. MATERIAL AND METHODS: A total of 263 women (median age 49 years, age range 26-73 years) underwent preoperative CTA examination before DIEP flap breast reconstruction. A CTA-dedicated protocol followed by 3D-reconstructions were performed. Identification, branching pattern, and caliber at origin were assessed for each perforator. Intraoperative findings were the standard of reference. The sensitivity, positive predictive value, and diagnostic accuracy of the preoperative CTA protocol were calculated. RESULTS: In 255/263 (97%) patients, the dominant perforators assessed by CTA resulted adequate for surgical reconstruction. In 260/263 (99%) cases, the imaging localization of the dominant perforators corresponded with those seen intraoperatively (mean errors ≤1 cm). The preoperative CTA imaging sensitivity, positive predictive value, and diagnostic accuracy in determining the localization of perforators were 99% (95% CI 98-100), 100% and 99% (95% CI 98-100), respectively. No statistically significant differences were found between the CTA findings and the surgical findings for the assessment of branching pattern and caliber of the dominant perforators (P < 0.001). CONCLUSION: The present protocol has demonstrated high accuracy in the CTA imaging assessment of the perforators before DIEP flap reconstruction with high reproducibility between CT and surgical findings.

Impact of opioid-free anesthesia on complications after deep inferior epigastric perforator flap surgery: A retrospective cohort study.

This study measured the number of complications after deep inferior epigastric perforator (DIEP) flap reconstruction performed under opioid-free anesthesia (OFA) combined with goal-directed fluid therapy or opioid anesthesia with liberal fluid therapy (OA). This retrospective cohort study consisted of 204 patients who underwent DIEP flap reconstruction at AZSint Jan Brugge between April 2014 and March 2019. Primary outcomes were complications, according to the Clavien-Dindo classification and the length of hospital stay (LOS). The secondary outcomes were flap failure, postoperative nausea and vomiting (PONV), postoperative pain, postoperative opioid consumption, and postoperative skin flap temperature. OFA included a combination of dexmedetomidine, lidocaine, and ketamine without any opioid administered pre- or intraoperatively. OA included a combination of sufentanil and remifentanil. OFA patients received strict goal-directed fluid therapy, whereas OA patients received liberal fluids to maintain perfusion pressure. All patients except 7 (TIVA with remifentanil) received inhalation anesthesia combined with an infusion of propofol. Of the 204 patients, 55 received OFA and 149 received OA. There were no differences in major complications, but fewer minor complications in the OFA group (17.9% vs. 51.4% and P < 0.001). Flap failure occurred in three patients of the OA group. Six patients developed flap thrombosis (five OA patients and one OFA patient). OFA was associated with fewer postoperative opioids, shorter LOS, less PONV, and less pain. In patients without previous nausea, the PONV incidence was higher in the OA group than in the OFA group (12.7% vs. 43.6% and P < 0.001). Patients with previous nausea more frequently required postoperative opioids and had a nausea rate of 60.87%.

Consecutive Bilateral Breast Reconstruction Using Stacked Abdominally Based and Posterior Thigh Free Flaps.

BACKGROUND: Multiple perforator flap breast reconstruction is an option that avoids implants in selected patients with minimal donor tissue. The technique addresses the need for additional skin to help create a breast envelope with more natural ptosis and additional volume to help create a body-appropriate breast mound while avoiding serial fat grafting. Using four flaps for the reconstruction of two breasts (bilateral stacked flap reconstruction) has recently become feasible with the advancement of microsurgical techniques, increased experience with alternative perforator flaps, and use of co-surgery. In this article, we describe our early experience with bilateral stacked flap breast reconstruction. METHODS: From January of 2014 to October of 2018, the senior co-surgeons performed 50 consecutive bilateral stacked flap operations at a single institution. All reconstructions were performed in delayed fashion with a mean operative time of 10 hours. Most breasts (94 percent) were reconstructed with a deep inferior epigastric perforator flap combined with a profunda artery perforator flap. Most flap microanastomoses (91.5 percent) were performed directly with internal mammary vessels. The larger of the two flaps was typically placed inferiorly (66 percent), but there was significant inset variability. RESULTS: Of 200 flaps, five were lost (2.5 percent). Seven take-backs were needed for a flap-related concern, which included two negative explorations and a flap salvage. The most common non-flap-related complication was a thigh wound (17 total, eight requiring a procedure). CONCLUSION: The authors' early experience suggests that bilateral stacked flap breast reconstruction is a powerful tool that can be performed with an acceptable microsurgical risk and an acceptable complication profile in highly selected patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Neoumbilicus after Selective Excision in Deep Inferior Epigastric Perforator Flap Breast Reconstruction.

The umbilicus offers no functional importance to the adult human but remains a key aesthetic landmark of the anterior abdominal wall, and its absence can be a cause for concern in aesthetic and reconstructive patients. Umbilical reconstruction or transposition for abdominoplasty and abdominally based flap operations is frequently complicated by umbilical death, infections, development of wounds needing prolonged wound care, and generally poor aesthetic outcomes. A multitude of techniques have been described to create the "ideal" neoumbilicus, but none has proven to be superior to the technique that comes before it. Our data demonstrate that, in a select set of patients, it may be beneficial to electively remove the umbilicus. Thus, umbilical reconstruction can be performed as an adjunct procedure to the primary operation with a superior aesthetic result and minimal risk for complications. This article describes the authors' approach to delayed neoumbilical reconstruction in patients undergoing elective umbilical resection.

Activity of Gas Transmitters in Vessels of the Anterior Abdominal Wall after Implantation of a Polypropylene Mesh.

The distribution of NO and H2S in the arterial vessels of the anterior abdominal wall after implantation of a polypropylene mesh was studied by immunohistochemical methods at different stages of healing of the surgical wound in mature male Wistar rats. The presence of enzymes of NO and H2S synthesis in the wall of arterial vessels of the soft tissues of the anterior abdominal wall has been established. It has been shown that endothelial NO synthase is localized exclusively in the endothelium of both large and small vessels. Cystathionine γ lyase in small vessels is located only in the endothelial lining, whereas in large arteries and vessels of medium caliber, it is located in the endothelium and in myocytes. Inducible NO synthase appears in the artery wall only in animals with implanted polypropylene mesh by day 5 of the postoperative period, reaching the maximum by day 10. The content and localization of cystathionine γ lyase in the vascular wall of sham-operated and experimental rats did not much differ from the control values.

Sonography of abdominal wall vascular malformation: a case report and review of the literature.

Vascular anomalies are classified as vascular tumors (VT) and vascular malformations (VM). VTs are divided according to their clinical behavior, while VMs are classified according to their flow characteristics, histopathologic features, and associations with other anomalies. Sonography emerges as the diagnostic imaging method of first choice for assessing abdominal wall disorders and masses, thus representing a valuable tool for the diagnosis and follow-up of abdominal wall VMs. In this review, we report a case of abdominal wall arteriovenous malformation (AVM) in a 17-year old and briefly discuss the cases of abdominal wall VMs.

Immediate unilateral breast reconstruction and contralateral breast augmentation with bilateral free deep inferior epigastric perforator flaps.

A 42-year-old woman was referred for consideration of left-sided mastectomy and immediate reconstruction. She previously had a bilateral breast augmentation using silicone implants. She desired to maintain her breast size and natural appearance. Owing to the availability of sufficient abdominal tissue, the option of an immediate unilateral breast reconstruction and contralateral augmentation with a differentially split deep inferior epigastric perforator flaps was offered to the patient. The patient had a successful reconstructive and contralateral symmetrising procedure with an uneventful postoperative recovery. She was satisfied with her breast size, which was achieved without the use of implants. In selected patients the free deep inferior epigastric perforator flap provides an appropriate option for unilateral breast reconstruction and contralateral breast augmentation. It has numerous advantages including making use of available excess abdominal tissue and avoiding implant related complications.

Refining our knowledge of macrovascular arteriovenous shunts (MAS): Anatomical and pathological studies.

BACKGROUND: The macrovascular arteriovenous shunt (MAS) connecting the deep inferior epigastric artery (DIEA) and superficial inferior epigastric vein (SIEV) in the abdominal wall has already been identified as an important structure, and further study has been deemed necessary to establish its role and function. METHODS: Review of CT angiograms (CTA) of 38 female patients was undertaken, by means of analysis of fine-cut axial images and three-dimensional image reconstructions of the cutaneous vasculature of the deep and superficial vasculature. In vivo dissection of the structure was also performed to establish its communications. Lastly, a histopathological analysis was carried out to investigate its intrinsic structure and function. RESULTS: The MAS was identified in both sides of the abdomen in all subjects and the diameter ranges from 0.72 to 2.81 mm with a median diameter of 1.28 mm. In vivo dissection revealed it as a distinct structure connecting the DIEA and SIEV. Pathological analysis showed that it has characteristics of both elastic and muscular arteries, which constitutes a new vessel. CONCLUSION: These further investigations have yielded a better understanding of the MAS shunt, its position, structure and function. This can be of crucial importance to reconstructive surgeons when raising the DIEP flap.

Transarterial embolization with n-butyl cyanoacrylate for the treatment of abdominal wall hemorrhage.

PURPOSE: We aimed to evaluate the effectiveness and safety of n-butyl cyanoacrylate (n-BCA) in the context of the transarterial embolization (TAE) of abdominal wall hemorrhage in an urgent scenario. METHODS: A retrospective study of cases admitted from January 2008 to December 2017 in the emergency unit of our institution revealed 11 patients with abdominal wall hemorrhage who underwent digital subtraction angiography and TAE with n-BCA. We analyzed the sex, age, hemorrhagic risk factors, etiology, embolized vessel, technical success (no rebleeding in the embolized area), clinical success (hemoglobin level control and hemodynamic stability after the procedure), complications inherent to the procedure, and clinical outcome (mortality in 30 days). RESULTS: The mean age was 63.4 years (52-83 years), with a predominance of the female sex (64%). The majority (91%) of patients presented hemorrhagic risk factors (chronic hepatopathy and anticoagulation drug usage). Spontaneous hemorrhage was present in 18% of patients, and the other 82% had an iatrogenic etiology. Technical success was achieved in 100% of the patients, which required the embolization of inferior epigastric artery in 10 patients (91%), circumflex iliac artery in 2 (18%), and superior epigastric artery in 1 (9%). Five patients were hemodynamically unstable, and despite achieving technical success, 4 (36%) died in less than 30 days due to decompensation of their clinical comorbidities caused by the acute phase. There were no complications inherent to the procedures. CONCLUSION: The present study concludes that TAE with n-BCA is a safe and effective treatment for abdominal wall hemorrhage in an urgent scenario, with high rates of technical and clinical success.

Estimation of Contralateral Perfusion in the DIEP Flap by Scoring the Midline-Crossing Vessels in Computed Tomographic Angiography.

BACKGROUND: In deep inferior epigastric perforator flap surgery, the amount of perfusion achievable in the contralateral side over a midline is unclear. Predicting contralateral perfusion preoperatively using computed tomographic angiography will allow efficient breast reconstruction with decreased complications. The authors used computed tomographic angiography to determine whether contralateral perfusion is related to blood vessel status across the midline. METHODS: Preoperative computed tomographic angiography scans and intraoperative perfusion in patients who underwent breast reconstruction with a deep inferior epigastric perforator flap between January of 2018 and July of 2018 were checked prospectively. A vessel scoring system was prepared according to vessel density across the flap midline on the scan (grade 0, no visible vessels; grade 1, visible vessels with disconnection or could not be judged as grade 0 or 2; grade 2, definite vessels). Intraoperative flap perfusion was confirmed with indocyanine green angiography. Postoperative fat necrosis was analyzed using ultrasonography. RESULTS: Ninety-four patients were analyzed. Mean maximal contralateral perfusion length was as follows: grade 0, 7.50 ± 1.89 cm; grade 1, 7.93 ± 2.01 cm; and grade 2, 10.14 ± 2.29 cm. Grade 2 had a statistically significantly greater contralateral perfusion length than grade 0 (p < 0.001) and grade 1 (p < 0.001). Fat necrosis occurred in 27.3 percent (grade 0), 19.1 percent (grade 1), and 8 percent (grade 2), which was statistically significant (p = 0.035). CONCLUSIONS: A definite vessel connection across the midline (as in grade 2) in preoperative computed tomographic angiography indicates that contralateral perfusion will be sufficiently achieved. This vessel scoring system would be helpful in predicting flap perfusion and planning the surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.