Monday, 14 March 2016

Top 50 Abdominal wall and acute abdomen Objective Type Questions And Answers

11.                Chylous ascites is the accumulation of chyle within the peritoneal cavity. Which of the following statement(s) is/are true concerning chylous ascites?

a.          The cisterna chyli lies at the anterior surface of the first and second lumbar vertebrae and receives lymphatic fluid from the mesenteric lymphatics
b.          Chylous ascites is most commonly associated with abdominal lymphoma
c.          Paracentesis and analysis of chylous fluid typically reveals elevated triglycerides, protein, and leukocyte levels with cytologic analysis reflecting the underlying presence of malignancy
d.          Treatment of chylous ascites with dietary manipulation will be successful in most cases
e.          The mortality rate in adults with chylous ascites is in excess of 50%
Answer: a, b, e

Chylous ascites is accumulation within the peritoneal cavity of chyle, a lymphatic fluid with a high lipid content. Access of intestinal lipids to the circulation is via mesenteric lymphatics that enter the cisterna chyle, which in turn becomes the thoracic duct which eventually enters the venous system at the junction of the left subclavian and internal jugular veins. The cisterna chyli lies at the anterior surface of the first and second lumbar vertebrae slightly to the right of the aorta. Chylous ascites may result from injury to major lymphatic duct or the cisterna. However for lymphatic leakage to persist, widespread occlusion of lymphaticovenous collaterals within the abdomen must be present. Malignancy is the predominant cause (88%) of spontaneous chylous ascites in adults, with lymphoma the most common malignancy. Diagnostic studies must include not only documentation of lymphatic origin of the abdominal fluid but also an attempt to delineate the cause of chylous ascites. Paracentesis and analysis of chylous fluid typically reveals elevated triglycerides, protein, and leukocyte levels, with a predominance of lymphocytes. Unfortunately, cytology is seldom positive despite the presence of malignancy. Lymphangiography may define the site of lymphatic leak for patients in whom the leak is from the cisterna or retroperitoneal lymphatics but not when from the mesenteric or hepatic lymphatics. Of noninvasive studies, CT is the test of choice, with a high diagnostic yield in nontraumatic chylous ascites in adults. Frequently, laparotomy with node biopsy is required for histology and typing in cases suspected to be cancer, particularly for lymphoma. Treatments for chylous ascites have been directed toward decreasing lymph and triglyceride accumulation. Successful resolution of chylous ascites has been achieved using a fat-restricted diet with added medium-chain triglycerides in an attempt to reduce lymphatic transport of triglycerides and perhaps intestinal lymph flow. Although there have been reports of success using such dietary manipulation, many failures have been reported. Therefore, in most patients with chylous ascites, treatment is likely to be successful only when directed toward the underlying cause. For patients with lymphoma, therapy effective against lymphoma is likely to eliminate chylous ascites.
The prognosis for patients with chylous ascites is much better in infants and children than in adults, principally because of the differences in causes of the condition. A mortality of 21% is reported in infants and children whereas a mortality of 88% has been noted in adults. Patients with chylous ascites with associated neoplasms typically have the gravest prognosis.

12.                Which of the statement(s) is/are true concerning laparoscopic hernia repair?

a.          General anesthesia is required
b.          Either an abdominal or preperitoneal approach is possible
c.          The use of prosthetic mesh is required in all variations
d.          Long-term results suggest that the laparoscopic approach is equal or better than traditional repairs
Answer: a, b, c

The laparoscopic approach to the repair of groin hernias has been recently developed. Either a transabdominal approach, wherein the peritoneum in the inguinal area is opened, and the repair is performed in the preperitoneum or an entirely preperitoneal approach can be used. In either technique, which are both performed under general anesthesia, after reducing the visceral contents out of the hernia, the repair is performed by placing a sheet of prosthetic mesh over the internal aspect of the inguinal floor and internal ring. Although early results and short-term benefits appear promising, long-term follow-up data is still not available to compare these techniques with traditional repairs.

13.                A 28-year-old woman with a history of an appendectomy presents with a nontender palpable mass in the right lower quadrant abdominal incision. The following statement(s) is/are true concerning the diagnosis and management of this patient.

a.          The best diagnostic test involves imaging of the abdominal wall by either CT or MRI
b.          Resection of the mass with a 2 cm margin is usually adequate
c.          Low dose radiation is a suitable alternative to surgery for primary treatment
d.          Re-resection for recurrence will likely have a higher rate of recurrence than for primary resection
Answer: a

Desmoid tumors are fibromatous tumors that may resemble low-grade fibrosarcoma but never metastasize. The tumor often infiltrates adjacent muscle and has a high incidence of recurrence despite seemingly adequate gross resection. The highest frequency is in women of childbearing age of which over 90% of tumors are abdominal in location. For abdominal wall desmoid tumors, approximately one-third are associated with a previous operation at the tumor site. The most frequent presenting symptom is a nontender, palpable abdominal wall mass. Diagnostic imaging is best carried out by CT or MRI, which delineate the extent of involvement of the layers of the abdominal wall and potential intraperitoneal extension. Initial treatment of abdominal wall desmoid tumors is surgical. Because the margins of the tumor are not easily determined and because the tumor often infiltrates muscle and periosteum, limited margins around the gross tumor frequently result in microscopic tumor at the margin. Recurrence rates for abdominal desmoid tumors vary from 9% to 40%, and recurrence is frequent with inadequate margins. A 5-cm margin of resection is considered adequate with mono bloc resection of rib cage, pubic or iliac bone or involved portions of organs such as bladder to achieve these margins. Reconstruction of the abdominal wall with polypropylene mesh is necessary in most cases. In patients in whom adequate margins of resection are achieved, there is no benefit from adjuvant radiotherapy. Second and third resections after recurrence have been associated with no higher rate of recurrence than primary resection. Radiotherapy alone has achieved local control in desmoid tumor in as many as 100% of tumors treated primarily and 75% of recurrent tumors. Radiation doses at least 60 Gy are considered necessary for consistent control. The large radiation dose risks major damage to adjacent bowel and therefore primary radiation treatment of abdominal wall desmoid tumors has a limited role.

14.                Which of the following statement(s) is/are true concerning repair of inguinal hernias?

a.          The Bassini repair approximates the transversus abdominis aponeurosis and transversalis fascia and the shelving edge of the inguinal ligament.
b.          The Bassini repair is an adequate repair for a femoral hernia
c.          A relaxing incision is important for repairs of direct and large indirect inguinal hernias to prevent excessive tension in the closure
d.          An advantage to the use of prosthetic material is the mesh incites formation of scar tissue to further increase tensile strength provided by the mesh alone
Answer: a, c, d

The Bassini repair is an inguinal hernia repair used world-wide and has been the standard against which other repairs are judged. The repair involves approximation of the transversus abdominis aponeurosis and transversalis fascia and the lateral edge of the rectus sheath to the shelving edge of the inguinal ligament. A femoral hernia cannot be repaired by the Bassini repair because the orifice to the femoral canal lies deep to the inguinal ligament. A Cooper’s ligament repair does approximate the structures to the transversalis fascia of the pectineal (Cooper’s) ligament between the pubic tubercle and the femoral vein and therefore is appropriate for repair of a femoral hernia. A relaxing incision for repairs of direct and large indirect inguinal hernias prevents excessive tension in the closure. There are an increasing number of proponents for the use of prosthetic material for the routine repair of inguinal hernias. Prosthetic material, such as polypropylene mesh, have been used for years for repair of large or recurrent inguinal and femoral hernias. The prosthetic mesh provides a low-tension repair for such large defects which otherwise could not be closed without excessive tension. In addition, the mesh incites the formation of scar tissue to further increase tensile strength beyond that provided by mesh alone. Results reported for inguinal hernia repairs using mesh have been excellent, although there is a slight risk of infection of the prosthetic material which must be considered.

15.                The following statement(s) is/are true concerning the epidemiology of inguinal hernias.

a.          Inguinal hernias occur with a male-to-female ratio of about 7:1
b.          Femoral and umbilical hernias are more common in women, with a female-to-male ratio of 4:1
c.          The frequency of inguinal hernias increases with age
d.          Almost all umbilical hernias occur in the pediatric age group
Answer: a, c

Inguinal hernias are the most frequently occurring hernia by a factor of five over other individual types. Umbilical hernias constitute about 14% of hernias, femoral hernias about 5%, and other types are rare. There is a male prevalence in inguinal hernias of about 7:1 (male-to-female), whereas there is a female dominance in femoral and umbilical hernias of 8:1 and 7:1 (female-to-male), respectively. For inguinal hernia, which occurs at all age levels, frequency increases with age. Umbilical hernias have a bimodal distribution, peaking in the pediatric population and then in the 40 to 60 year group, in which the hernias are principally paraumbilical.

16.                A 77-year-old multiparous female presents with a bowel obstruction. She has no previous abdominal operations and no abdominal wall hernias can be detected. In addition to her abdominal symptoms, she reports pain in her right medial thigh. The following statement(s) is/are true concerning her diagnosis and management.

a.          Expectant management with nasogastric suction and IV fluid replacement is indicated
b.          A right groin approach is indicated for exploration and repair of the presumed hernia
c.          The use of a polypropylene mesh will likely be necessary for repair
d.          A correct diagnosis can usually be made by visualizing an external mass in the upper, medial thigh
Answer: c

An obturator hernia is a hernia that occurs through the obturator canal, accompanied by the obturator vessels and the obturator nerve. Although rare, most obturator hernias occur in older multiparous women and are predominantly right-sided. Symptoms are frequently intermittent but tend to be acute and become increasingly severe with incarceration of the hernia. Intestinal symptoms predominate, but dysesthesia or pain in the medial thigh with occasional radiation to the hip is often present. Dysesthesia results from compression of either division of the obturator nerve. Although the hernia is never externally visible, in a small percentage of patients a mass can be palpated in the upper, medial thigh. A correct diagnosis of obturator hernia is made in only about one-third of patients presenting with intestinal obstruction. Plain radiographs are seldom helpful, however a CT scan will usually confirm the diagnosis. Treatment is operative. There is no place for expectant therapy, especially in a patient with pain an parasthesias along the inner aspect of the thigh or with clinical or radiographic evidence of bowel obstruction. Many surgical approaches have been promoted, but the transabdominal approach should be used because it has several advantages. It best confirms the diagnosis and exposes the obturator canal, orifice, vessels, and nerve, also permitting bowel resection when required. The sac is dealt with in a standard fashion. The hernia defect should be repaired, but repair usually requires a polypropylene mesh patch because the margin of the defect cannot be approximated primarily.

17.                The following statement(s) is/are true concerning umbilical hernias in adults.

a.          Most umbilical hernias in adults are the result of a congenital defect carried into adulthood
b.          A paraumbilical hernia typically occurs in multiparous females
c.          The presence of ascites is a contraindication to elective umbilical hernia repair.
d.          Incarceration is uncommon with umbilical hernias
Answer: b

An umbilical hernia in a child is usually considered to be congenital. Only about 10% of umbilical hernias in adults are thought to be the result of a congenital defect carried into adulthood. Most adult umbilical hernias are acquired and are called paraumbilical hernias. The paraumbilical hernia typically occurs in a multiparous female. Other patients with increased intraabdominal pressure, particularly with concomitant chronic abdominal distension as from ascites, are also at increased risk for the development of paraumbilical hernias. Umbilical and paraumbilical hernias vary from small to extremely large. Incarceration is frequent in the large hernias, which typically have a small neck.
Indications for umbilical hernia repair in adults include symptoms, incarceration, large hernia relative to the neck, and trophic changes in the overlying skin. Among adults with associated ascites, repair is advocated to avoid potentially serious complications. The presence of discoloration or ulceration of overlying skin or a rapid increase in size of the hernia herald impending rupture. Spontaneous rupture of the hernia in these patients can be catastrophic and is frequently associated with mortality rates approaching 30%. By comparison, elective umbilical hernia repair can be performed safely in patients with ascites with acceptable morbidity and mortality.

18.                Retroperitoneal fibrosis is a fibrosing condition of retroperitoneum, which is of significance as it generally encompasses the ureters and eventually causes hydronephrosis and kidney damage. Which of the following statement(s) is/are true concerning this condition?

a.          The majority of cases are idiopathic in nature
b.          A history of use of methysergide for treatment of migraine headaches would be significant
c.          There is no known association of malignancy with retroperitoneal fibrosis
d.          The disease occurs more commonly in women than in men
Answer: a, b

Retroperitoneal fibrosis is a rare condition in which fibrosis develops in the retroperitoneal space. The ureters frequently will become encompassed by the process eventually causing hydronephrosis and kidney damage. Retroperitoneal fibrosis occurs most commonly in the fifth and sixth decades with a 2:1 male-female predominance. The pathophysiology of retroperitoneal fibrosis remains to be delineated. In fully two-thirds of cases, retroperitoneal fibrosis is idiopathic, however, an autoimmune process has been suggested as a potential cause. About 12% of cases of retroperitoneal fibrosis have been associated with the use of methysergide, a serotonin agonist used for vascular and migraine headache, and in this subgroup females outnumber males 2:1. Primary or metastatic malignancy in the retroperitoneum is found in 8% of patients with retroperitoneal fibrosis. Sarcomas are the most common primary tumors, but non-Hodgkin and Hodgkin lymphomas and ureteral cancer have also been found. Metastases have originated from cancer of the stomach, breast, colon, carcinoid, pancreas, prostate, ovary, and cervix. The focus of tumor may be small but may induce desmoplasia that is grossly indistinguishable from benign variance of retroperitoneal fibrosis.

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