Q What is radical esophagectomy?
A It includes both two field and three field esophagectomy
Two field esophagectomy
For tumors of the middle or lower thoracic esophagus, the en-bloc specimen would include, in addition to the tumor-bearing organ, the pericardium anteriorly
both pleural surfaces laterally, thoracic duct and all other lympho-areolar tissue wedged posteriorly between the esophagus and the spine.
Additionally, for tumors traversing the diaphragm, a 1-in cuff of diaphragm is excised circumferentially around the esophagus.
The associated two-field lymphadenectomy includes en-bloc resection of all nodal groups between the tracheal bifurcation superiorly to the celiac axis inferiorly.
Lymph node stations include
Periesophageal, parahiatal, subcarinal, and aortopulmonary window nodes.
In the abdomen, an upper abdominal and retroperitoneal node dissection is performed, and includes resection of the celiac, splenic, common hepatic, left gastric, lesser curvature, and parahiatal nodes
Three field esophagectomy
40% of patients who had resected squamous cell esophageal cancer developed isolated cervical lymph node metastases
The additional third field of dissection included excision of the nodes along both recurrent nerves as they course through the mediastinum and neck, as well as a modified cervical node dissection. The latter includes the nodes posterior and lateral to the internal jugular vein and an infraomohyoid node dissection bilaterally
There is substantial morbidity rates associated with three-field lymphadenectomy, recent research focuses on refining patient selection for this procedure. From mostly retrospective studies, it can be shown that survival advantage may not be demonstrable for lower-third tumors], for patients who have positive nodes in all three surgical fields where intramural metastases are present, or in those who have five or more involved nodes
Q Why AST and ALT get elevated in Acute Cholecystitis?
A There are two reasons given in Sabiston text book of surgery which makes interesting reading
1. Direct contact of inflamed gallbladder with liver surface enciting a response
2. Sepsis in general brings about changes in heptocyte cell membrane
Q Differences between Non Cirrhotic Portal fibrosis and Extra hepatic portal vein obstruction
1. Etiology- At birth infection or a prothrombotic event precipitates thrombosis in the portal vein or its radicals. It is NCPF if thrombosis occurs in Medium or small branch of Portal vein but it is EHPVO if the thrombosis is a major event and affects the major branch.
Also if a major thrombosis recanalises it may lead to NCPF.
2. pathology - In NCPF portal vein is thickened and dilated with thick sclerosed walls.
3. HPE- Obliterative porto venopathy ie subendothelial thickening of portal venous branches . There is intimal thickening of intrahepatic portal venous channels in NCPF
4. Wedged Hepatic venous pressure is normal or only slightly elevated in NCPF
5. Clinical features- young, low socio economic status, male, well tolerated episodes of upper GI bleed, hypersplenism in NCPF
6. Lab parameters show anemia and hypersplenism
7. Ultrasound- Ultrasonography is the investigation of choice. It shows a dilated and patent splenoportal axis with significantly thickened walls of the portal vein and its main branches.
Q Why Ileocaecal region is the most common site of intestinal Tuberculosis
This is because of
- i) Ileocaecal region is the point of physiological stagnation
- ii) It has the maximum number of lymph nodes in the small intestine
iii) Minimal digestive activity
- iv) Increased rate of fluid and electrolyte absorbtion occurs here
Q How does alcohol produce chronic pancreatitis?
Direct toxic effect
Ethanol forms acetaldehyde which stimulates pancreatic stellate cells and leads to deposition of coolagen
Pancreatic stone Protein (PSP) or Lithostatin is decreased by alchol. This protein is required to prevent precipitaion of calcium crstals in pancreatic ducts.
Then there is the question why some patients who drink excessive alcohol do not develop pancreatitis
Alcoholic pancreatitis occur in patients who are gentetically predisopsed. Mutations of CFTR, SPINK1 and PRSS are important
Q) What is the mechanism of pain
Patients who have undergone resection histologic changes are seen in the nerves within the pancreas. There is an increased mean diameter of the nerves and altered structure to the nerve sheath. Neurotransmitters, including substance P, neuropeptide YY, and calcitonin gene-related peptide (CGRP), are also shown to be overexpressed. This overexpression creates an environment for overstimulation of the local pain-sensing apparatus and a potential humoral component for pain sensation in the setting of chronic pancreatitis.
Q What is the meaning of Borderline Resectability in Pancreatic tumors?
A In Carcinoma head of pancreas Varadhachary and colleagues introduced the term borderline resectable to include those tumors with limited arterial abutment (defined as tumor-vessel contact of <180°) or venous abutment or encasement (defined as tumor-vessel contact of >180°). The introduction of the terms abutment and encasement allowed physicians to use accurate terminology in contrast to the vague descriptors used in the past such as venous “involvement,” which may have been used to describe subtle tumor abutment and near-complete vessel occlusion.
Also added are tumors with arterial abutment in which resection maybe possible after neoadjuvant therapy
Short segment venous involvement
Further Refinement to the definition was done by Katz
Katz Type Patient, Tumor, or Disease Characteristics
A CT images to include 1 or more of the following findings:
(1) tumor abutment (180° or less of the circumference of the vessel) of the SMA or celiac axis
(2) tumor abutment or encasement (>180° of the circumference of the vessel) of a short segment of the hepatic artery, typically at the origin of the gastroduodenal artery
(3) short-segment occlusion of the SMV, PV, or SMV-PV confluence that was amenable to vascular resection and reconstruction because of a patent SMV and PV below and above the area of tumor-related occlusion
B Patients with borderline resectable disease because of a concern for possible extrapancreatic metastatic disease. This subgroup included those with CT findings suspicious for, but not diagnostic of, metastatic disease and those with known N1 disease from either prereferral laparotomy or EUS-guided FNA
C Patients with borderline resectable disease because of a marginal performance status (Zubrod 3), or those with a better performance status and significant preexisting medical comorbidity believed to require protracted evaluation that precluded immediate surgery.