Bestoun H. Ahmed

Aberrant crypt foci as precursors in colorectal cancer progression.

Colorectal cancer progression originates when accumulated genetic and epigenetic alterations cause genomic instability and a malignant phenotype. Subsequent molecular pathway deregulation leads to histopathologic changes that are clinically evident as aberrant crypt foci (ACF) and visualized by high‐magnification chromoscopic colonoscopy. ACF are biomarkers of increased colorectal cancer risk, particularly those with dysplastic features. Genetic profiling using genomic instability, loss of heterozygosity, and methylation analysis has revealed a minority population of ACF genotypically analogous to cancer. J. Surg. Oncol. 2008;98:207–213.

Proton therapy may allow for comprehensive elective nodal coverage for patients receiving neoadjuvant radiotherapy for localized pancreatic head cancers.

BACKGROUND Neoadjuvant radiotherapy has the potential to improve local disease control for patients with localized pancreatic cancers. Concern about an increased risk of surgical complications due to small bowel and gastric exposure, however, has limited enthusiasm for this approach. Dosimetric studies have demonstrated the potential for proton therapy to reduce intestinal exposure compared with X-ray-based therapy. We sought to determine if neoadjuvant proton therapy allowed for field expansions to cover high-risk nodal stations in addition to the primary tumor. METHODS Twelve consecutive patients with nonmetastatic cancers of the pancreatic head underwent proton-based planning for neoadjuvant radiotherapy. Gross tumor volume was contoured using diagnostic computed tomography (CT) scans with oral and intravenous contrast. Four-dimensional planning scans were utilized to define an internal clinical target volume (ICTV). Five-mm planning target volume (PTV) expansions on the ICTV were generated to establish an initial PTV (PTV1). A second PTV was created using the initial PTV but was expanded to include the high-risk nodal targets as defined by the RTOG contouring atlas (PTV2). Optimized proton plans were generated for both PTVs for each patient. All PTVs received a dose of 50.4 cobalt gray equivalent (CGE). Normal-tissue exposures to the small bowel space, stomach, right kidney, left kidney and liver were recorded. Point spinal cord dose was limited to 45 CGE. RESULTS Median PTV1 volume was 308.75 cm(3) (range, 133.33-495.61 cm(3)). Median PTV2 volume was 541.75 cm(3) (range, 399.44-691.14 cm(3)). In spite of the substantial enlargement of the PTV when high-risk lymph nodes were included in the treatment volume, normal-tissue exposures (stomach, bowel space, liver, and kidneys) were only minimally increased relative to the exposures seen when only the gross tumor target was treated. CONCLUSIONS Proton therapy appears to allow for field expansions to cover high-risk lymph nodes without significantly increasing critical normal-tissue exposure in the neoadjuvant setting.

Laparoscopic management of sigmoidorectal intussusception.

This case of sigmoidorectal intussusception was caused by a large tubovillous adenoma and managed with laparoscopic sigmoidectomy.

Surgery for Peptic Ulcer Disease

Abstract Gastroduodenal peptic ulcer disease (PUD) is a common problem with significant geographic variation in prevalence. In Western countries, the incidence of PUD has steadily declined and the prevalence is much higher in developing countries. Such variations are likely related to the prevalence of Helicobacter pylori, smoking, and the use of ulcerogenic drugs, such as nonsteroidal antiinflammatory drugs. The advent of histamine H2-receptor antagonists (H2 blockers) in the 1970s and the development of proton pump inhibitors (PPIs) in the late 1980s led to further acid reduction and faster, more efficient healing of active ulcer disease. The combined use of PPIs and endoscopic treatment has further decreased the need for emergency operation. PUD complications include bleeding, perforation, and gastric outlet obstruction. There has been a significant downward trend in the incidence of these complications. Complications of PUD also vary depending on the geographic location. Bleeding is the most common in the United States, and obstruction may be more common in other locations in the world. The goals of surgical procedures are to permit ulcer healing, prevent or treat ulcer complications, address the underlying ulcer etiology, and minimize postoperative digestive consequences.

Minimally invasive Ivor-Lewis esophagectomy for esophageal cancer with right aortic arch

Right aortic arch (RAA) is a rare congenital vascular abnormality in which the aorta descends in the right thorax and encircles the esophagus. Historically, esophagectomy for patients for RAA is done through a left thoracotomy as exposure and mobilization of the esophagus is difficult through a right thoracotomy. A 73-year-old male was found to have an esophageal adenocarcinoma. Endoscopic ultrasound showed a T3N0 lesion in the lower third of the esophagus. PET CT demonstrated a circumferential lesion without evidence of distant disease or involved lymph nodes and a RAA which was not associated with congenital heart disease or symptoms. The patient received neo-adjuvant chemoradiation (50.4 Gy) with carboplatin and paclitaxel. Minimally invasive Ivor-Lewis esophagectomy (MIE) utilizing conventional right thoracoscopy was done. Esophageal mobilization, transection and mediastinal lymph node dissection was performed through anteriorly placed trocars, thereby avoiding the right side descending aorta that is lying anterior and to the right of the esophagus. In this video we demonstrate MIE utilizing right thoracoscopy. Total operative time was 250 minutes and the patient was discharged home on post-operative day 8. Final pathology showed complete pathological response, with 0/22 involved lymph nodes and uninvolved surgical margins. Minimally invasive esophagectomy has been reported to deliver superior outcomes to the open approach. MIE can be performed in selected patients with RAA, and herein we demonstrate a minimally invasive option for the treatment of distal esophageal cancer in patients with RAA. To our knowledge this is the 1st reported case in the English literature utilizing this approach in patient with RAA.

Minimally Invasive Surgical Techniques for Cancers of the Small Intestine

The rarity of small intestinal malignancies and the advanced nature at presentation have traditionally limited the use of laparoscopic operations in dealing with cancers of the small intestine. However, in the recent past, with advanced experience and improved technology, laparoscopic surgery for these disorders is gaining popularity in mainstream practice. This chapter provides an insight into the disease processes, diagnosis, and treatment of small intestinal neoplasms, while giving a step-by-step description on performing these complex procedures using minimally invasive surgical techniques.