Laparoscopic vs open resection for rectal carcinoma--a prospective analysis.

UNLABELLED: In the recent years, laparoscopic surgery has established itself worldwide as a method of treatment for colorectal cancer. Several prospective randomized trials comparing laparoscopic with open resection of the colon, showing the advantages of laparoscopic surgery in terms of a shorter hospital stay, faster recovery of intestinal transit and physical activity in equivalent survival and recurrence rate. However, in many of the studies the data on laparoscopic resection for rectal cancer are scarce and it is still controversial. AIM: In this report, we aimed to make a comparative analysis of the clinical and oncological outcomes after laparoscopic and open rectal resection in patients with a rectal cancer. MATERIAL AND METHODS: We compare and analyze prospectively data from two groups of patients with rectal cancer--66 undergoing laparoscopic and 47 undergoing open rectal resection respectively. Both groups were selected with comparable demographic characteristics (gender, age, body mass index), ASA class (American Society of Anesthesiologists), tumor stage, type of neoadjuvant radiochemotherapy and operations. The data were statistically processed. RESULTS: The mean age was 61, body mass index ranged from 18 to 42. The frequency of conversion was 6.06%. Postoperative complications were similar in both groups, except for wound infection was lower for the laparoscopic group (p = 0.02). The laparoscopic group had a shorter hospital stay (7 and 5 days respectively p < 0.01), faster recovery of intestinal motility (3 and 4.5 days respectively, p < 0.001) compared with the open group. Three-year survival rate and the rate of local and late recurrences were identical in both groups. CONCLUSIONS: Laparoscopic surgery is applicable in the treatment of rectal cancer with similar oncologic outcomes compared with conventional surgery and has all the advantages of miniinvasive methods. There is a need for further randomized studies to refine the applicability of laparoscopic rectal resection for cancer.

Poster - Thur Eve - 22: Bone heterogeneity in kV x-ray radiotherapy.

This study evaluated the dosimetric impact of bone heterogeneity on the surface dose and dose prescription, when dose is assumed to be prescribed on a homogeneous medium in kV x-ray radiotherapy. A heterogeneous phantom containing a thin water layer (thickness = 1-5 mm) over a bone (thickness =1 cm) was used to mimic treatment sites of forehead, knee and chest wall. The phantom was irradiated by a 220 kVp photon beam with field size of 5 cm diameter. Percentage depth dose, surface dose and photon energy spectrum with different thicknesses of water were determined using Monte Carlo simulations (the EGSnrc code) with experimental verifications using parallel-plate ionization chamber and radiochormatic film. Our results (treatment cone of 5 cm diameter) showed that the surface dose increased in a range of 2.5-3.7% when the water layer above the bone was increased from 1 to 5 mm. However, the surface dose did not increase linearly with the increase of water thickness, and the maximum increase of surface dose was found at a water thickness of 3 mm. Results of the percentage depth dose showed that the maximum bone dose was about 210% higher than the surface dose in the heterogeneous phantom. It is concluded that in treatment sites having a thin layer of tissue over a bone in kV x-ray radiotherapy, if increased surface dose due to bone heterogeneity is not considered, this will result in an additional dosimetric uncertainty narrowing down the total error margin (5%).

SU-E-T-571: Prostate IMRT QA: Prediction of the Range of Rectal NTCP Using a 2D Field Approach Based on Variations of the Rectal Wall Motion and Thickness.

PURPOSE: The aims of this study is to (1) introduce a 2D field of possible rectal normal tissue complication probability (NTCP) in prostate intensity modulated radiotherapy (IMRT) plan, so that based on a given prescribed dose the rectal NTCP is merely a function of the rectal wall thickness and rectal motion; and (2) separate the 2D field of rectal NTCP into area of low risk and area of high risk for rectal toxicity < Grade II, based on the threshold rectal NTCP. METHODS: The 2D field of NTCP model was developed using ten randomly selected prostate IMRT plans. The clinical rectal geometry was initially represented by the cylindrical contour in the treatment planning system. Different combinations of rectal motions, rectal wall thicknesses, planning target volume margins and prescribed doses were used to determine the NTCP in prostate IMRT plans. RESULTS: It was found that the functions bordering the 2D field for the given AP, LR and SI direction can be described as exponential, quadratic and linear equations, respectively. A ratio of the area of 2D field containing data of the low risk NTCP to the entire area of the field was introduced and calculated. Although our method is based on the Kutcher's dose response model and published tissue parameters, other mathematical models can be used in our approach. CONCLUSIONS: The 2D field of rectal NTCP is useful to estimate the rectal NTCP range in the prostate pre-treatment and treatment QA. Our method can determine the patient's threshold immobilization for a given rectal wall thickness so that prescribed dose can be delivered to the prostate to avoid rectal complication. Our method is also applicable to multi-phase prostate IMRT, and can be adapted to any treatment planning systems.

[Rupture of splenic artery aneurysm--life-threatening condition for women during pregnancy and after birth (with report of one case)].

Spontaneous rupture of a splenic artery aneurysm is an uncommon and usually catastrophic event during pregnancy and puerperium. The mortality rate among pregnant women is very high at 75% with a fetus mortality rate of 95%. This report describes the clinical course of a 25-year-old woman with hemorrhagic shock four hours after elective Cesarean Section. Symptoms like hypotension, tachycardia, dyspnoe were initially suggestive of pulmonary embolism. Ultrasound demonstrated a nonechogenic mass in the abdomen suggestive of a fluid collection. Ruptured splenic artery aneurysm was recognized during the second emergency laparotomy for hemoperitoneum. Splenectomy was performed. The outcome for the patient was good. We underline that the only way to avoid a fatal event is to know and to think about this rare but very important complication in any woman with unexplained abdominal pain or with clear signs of haemorrhage during pregnancy or shortly after delivery.

Poster - Thurs Eve-24: Dosimetry study on the penumbra region for the irregular MLC fields with stepping patterns.

The aim of this study is to investigate the dosimetric effect in the penumbra region for the multi-leaf collimator (MLC) fields with stepping patterns. Various irregular MLC fields with different stepping patterns were designed. Radiographic films were used to measure the beam profiles (cross-plane (X1-X2 jaw) and in-plane (Y1-Y2 jaw)) for different MLC field configurations of varying lengths of protruded leaves adjacent (on one or both sides) to the beam profile axis. 6 MV photon beams produced by the Varian 21 EX linear accelerator with 120-leaf Millennium MLC were used. The results showed that the penumbra widths (10% - 90%) of the profiles (cross-plane) with 0.5 cm gap width increased with the protruded lengths of the neighbouring leaves, while the penumbra widths did not vary too much for the larger gap widths of 1 cm and 1.5 cm. The neighbouring leaf's influence on the profile was very insignificant, when the distance between the profile and neighbouring leaf edge was larger than 1 cm. Moreover, when both the upper and lower portions of leaves were moved out forming a gap for the profile, the dose at the "edge" region was decreased by about 20% and 6% when the protruded lengths of the leaves were 0.5 cm and 1 cm, respectively. It is important to understand the dosimetric effect in the penumbra region for irregular MLC fields with stepping leaf patterns, especially during the commissioning process for the conformal external beam and intensity modulated radiation therapy.

Sci-Thurs PM: Delivery-01: Sliding Window IMRT: Uncertainties of the leading edge and plateau of the beam profile.

The aim of this work is to analyze the dependence of the dose profile uncertainties for the sliding window IMRT (SW-IMRT) beams under the condition of an extreme dose rate (DR) and leaf velocity (LV). The deviations of the edges and plateau for the beam profiles of small number of MUs delivered using the dynamic MLC were studied. Field sizes with lengths of 5 and 10 cm were irradiated by photon beams of 2-8 MU/beam, DR = 100-600 MU/min and LS = 1-5 cm/s. Kodak TL radiographic films were used in the measurement. The photon beams (6 and 15 MV) were produced by a Varian 21EX Linac with a 120-leaf MLC. It is found that the MLC cannot keep the leaves moving with a proper speed continuously under a stable DR when beam of small MUs are irradiated. For example, the dynamic MLC needs 1.2 s and 12 MU to irradiate a field of 5 cm length with 2 MU using DR = 600 MU/min and LC = 5 cm/s. The plateau of the beam profile has several sinusoidal periods of about 150 ms. The magnitude of the plateau uncertainties was about 7% and 15% for the dose of the beam with DR = 400 and 600 MU/min (2 MU/beam), respectively. It is concluded that SW-IMRT beams of more than 10 MUs, delivered with 1 cm/s ⩽ LV ⩽ 5 cm/s and 100 MU/min ⩽ DR ⩽ 600 MU/min, have a good agreement between the delivered and planned dose profiles.

Optimization of helical tomotherapy treatment plans for prostate cancer.

Helical tomotherapy (HT) is a novel treatment approach where the ring gantry irradiation geometry of a helical CT scanner is combined with an intensity-modulated megavoltage x-ray fan beam. An inverse treatment planning system (TomoTherapy Inc., Madison) was used to optimize the treatment plans for ten randomly selected prostate patients. Five different sets of margins (2, 5, 7.5 and 10 mm uniform 3D margins and a non-uniform margin of 5 to 10 mm) were employed for the prostate (GTV2) and seminal vesicles (GTV1). The dose distribution was evaluated in targets, rectum, bladder and femoral heads. HT plans are characterized by a rapid dose fall off around the target in all directions resulting in low doses (less than 30% of the dose at ICRU reference point) to the femurs in all cases. Up to a margin of 5 mm for target structures, it was always possible to satisfy the requirements for dose delivery set by RTOG protocol P-0126. Using a 'class solution', HT plans require minimal operator interaction and result in excellent sparing of normal structures in prostate radiotherapy.

A clinical study of a silicate toothpaste with extract from propolis.

Propolis is bee-produced substance with pronounced anti-inflammatory effect. It is an ingredient of many drugs; it is added to toothpastes as a prophylactic component for periodontal diseases. The plaque-cleaning, plaque-inhibiting and anti-inflammatory actions of the silicate paste were studied. The study included 42 individuals in good clinical health and a minimum of 20 intact teeth - 11, 16, 24, 31, 36, 46. Control exams were performed on days 1, 7, 14, 21 and 28. The baseline values gradually decreased after each control tooth brushing with a statistically significant difference between them. The toothpaste shows very good plaque-cleaning, plaque-inhibiting and anti-inflammatory effect.

Abdominoperineal resection and perineal colostomy for low rectal cancer. The Lazaro da Silva technique.

PURPOSE: We sought to evaluate a new technique for creation of a continent perineal colostomy following abdominoperineal resection (APR) of the rectum for low rectal cancer. METHODS: Nine selected patients with low rectal cancer (two males; median age, 55.6 years; classified as Dukes A, 6 patients and as Dukes B, 3 patients) underwent APR. Following this, the original Lazaro da Silva technique was used as follows: 1) for performance of three circular myotomies in the distal sigmoid with a distance between each couple of no more than 8 cm; 2) repair of the myotomies, thus creating three circular colonic valves, the most distal of which remained extraperitoneally; 3) for construction of a perineal colostomy lying flush with the perineal skin; 4) after the patient starts consuming a regular diet, enemas through the perineal stoma are done, usually twice per week, to achieve defecation. Functional outcome was assessed by evaluation of bowel movements and neoanal continence. RESULTS: There were no deaths. From January 1994 until October 1995, no tumor recurrence has occurred, and fecal continence has been good. Four of the patients were able to defecate without enemas (2-4 times per week), and in five patients the self-administration of enemas (2-4 times a week) were necessary to accomplish defecation. CONCLUSION: Initial results with the Lazaro da Silva technique have been encouraging.

Stercoral perforation of the normal colon: report of five cases.

A series of five consecutive patients with stercoral perforation of the colon is presented. Four of the patients had free perforation and one had an abscess between the splenic flexure, spleen and surrounding organs, a yet unreported entity. All patients underwent emergency surgery including laparostomy with repeated explorations and lavages in two of them. The ethiology, pathophysiology and treatment of the condition are updated. A graphic algorithm for decision-making in appropriately dealing with stercoral perforation of the colon is proposed.

Ingested foreign bodies of the gastrointestinal tract: retrospective analysis of 542 cases.

Ingested foreign bodies (FBs) present a common clinical problem. As the incidence of FBs requiring operative removal varies from 1% to 14%, it was decided to perform this study and compare the data with those from the world literature, as well as to outline an algorithm for management, including indications for surgery. We reviewed all patients with FB ingestion from 1973 to 1993. There were 542 patients with 1203 ingestions, aged 15 to 82 years. Among them, 69. 9% (n = 379) were jail inmates at the time of ingestion, 22.9% (n = 124) had a history of psychosis, and 7.2% (n = 39) were alcoholics or denture-wearing elderly subjects. Most foreign bodies passed spontaneously (75.6%; n = 410). Endoscopic removal was possible in 19. 5% (n = 106) and was not associated with any morbidity. Only 4.8% (n = 26) required surgery. Of the latter, 30.8% (n = 8) had long gastric FBs with no tendency for distal passage and were removed via gastrotomy; 15.4% (n = 4) had thin, sharp FBs, causing perforation; and 53.8% (n = 14) had FBs impacted in the ileocecal region, which were removed via appendicostomy. Conservative approach to FB ingestion is justified, although early endoscopic removal from the stomach is recommended. In cases of failure, surgical removal for gastric FBs longer than 7.0 cm is wise. Thin, sharp FBs require a high index of suspicion because they carry a higher risk for perforation. The ileocecal region is the most common site of impaction. Removal of the FB via appendicostomy is the safest option and should not be delayed more than 48 hours.

The Lichtenstein open tension-free inguinal hernia repair using a new prosthetic mesh-Bulgarian irresorbable ampoxen.

The routine use of mesh for repair of inguinal hernia has been popularized by Lichtenstein and coworkers. We adopted this technique and performed it widely using a mesh unknown in the Western world. Ampoxen [multifilamented polycaproamide, impregnated with 5-Nitro-8-Hydroxyquinolinum (Nitroxolinum, DCI), MEDICA, SA, Sandanski, Bulgaria] was discovered in 1975 and proved to be an excellent prosthetic material for replacement of attenuated or destroyed abdominal wall; furthermore, this mesh is very cheap and became widely applicable in our country. This report describes our experience with the first 846 adult inguinal hernia repairs under local anesthesia using Ampoxen. All 846 patients had excellent results, without recurrence. There were nine wound infections (1.1%), 16 testicular oedemas (1.9%), no seromata and no deaths. In no patient was the prosthetic mesh removed. There were no complications related to the use of Ampoxen; this mesh is permanent, has a great degree of fibrous tissue reaction, and wide spectrum antimicrobic activity. We advocate the Lichtenstein technique using irresorbable mesh (particularly Ampoxen) for all adult groin hernias except Types 1 and 2 (according to Nyhus' classification), and for all adult recurrent groin hernias.

Comparison between three methods for laparostomy in the treatment of generalized feculent peritonitis

Recentemente, o conceito abdômen aberto tem sido utilizado frequentemente em pacientes com peritonite generalizada. Como não existe evidências objetivas que um tipo de laparotomia é superior a outra, os autores decidiram comparar três técnicas de laparotomia em série de 92 pacientes consecutivos tratados em sua instituição.

Acquired benign esophago-airway fistulas.

MATERIALS AND METHODS: Over a period of 25 years, 35 patients with acquired benign esophago-airway fistulas were treated. Only two of them were female. The etiology of the communications was corrosive burns, penetrating wounds, postoperative and endoscopic lesions, esophageal diverticula, prolonged ventilatory assistance, pleural empyema and foreign bodies. Radical operative treatment was performed in 31 cases. In four of these the procedure was palliative, because of poor general condition and lung complications. The operative approach was chosen after precise endoscopic and contrast X-ray examinations. A cervical approach with partial median sternotomy to the third intercostal space was performed in 19 patients. In the rest of the patients a thoracotomy was performed. Simple excision of the fistula, longitudinal suture of the trachea and horizontal suture of the esophagus was the method of choice in nine patients. A flap from the left sternocleidomastoid was additionally interposed in front of the esophagus in 12 patients. In six cases circular resection, reconstruction of the trachea and plastic suture of the esophagus were performed. Esophagectomy with ensuing colon substitution was necessary in four patients. RESULTS: Excellent or good results were obtained in 29 of the 31 patients operated on. We had two deaths in the early postoperative period (6.8%) due to lung complications in patients with chemical burns of the esophagus. The operated patients were followed up for period ranging from 3 to 20 years. CONCLUSION: Acquired esophago-respiratory fistulas require emergency surgical treatment. The proper choice of operative approach is largely dependent on the precise diagnosis. Preoperative intensive care and metabolic balance are important factors in this report. Radical operative treatment depends on the basic disease, local inflammation and lung complications.

Stercoral perforation of the colon.

An elderly man presented with abdominal pain and signs of peritonitis. Emergency laparotomy was performed and a stercoral perforation of the cecum was found with a large scybalum plugging the defect. The patient was treated with right colectomy and a stoma was formed from the terminal ileum and transverse colon. Stercoral perforation of the colon is extremely unusual and carries high morbidity and mortality. The etiology, diagnosis and treatment of the condition are briefly discussed.

Perforated nonspecific ulcer of the sigmoid colon: four cases in one year.

During 1993, four consecutive adult male patients underwent emergency surgery for free perforation of nonspecific sigmoid colon ulcers. All four patients presented with peritonitis and in each patient the Hartmann's procedure was performed. In each patient there was a single perforation but two of the patients presented with multiple erosions and ulcerations, and the other two- with solitary ulcers. All patients survived and had uneventful postoperative course. Three of them underwent uncomplicated restorations of the bowel continuity. Colonoscopy should be attempted in every suspicious case to confirm or to exclude the presence of nonspecific colon ulcers that could threat patient's life.

[The basic principles of the antibiotic therapy of burn patients]. / Osnovni printsipi na antibiotichnata terapiia pri bolni s izgariane.

Proceeding from many years experience with antibiotic treatment of bacterial infections in burnt patients, accumulated in the Section of Burns and Plastic Surgery, and pertinent literature reports, the basic principles of antibacterial therapy in this contingency of patients are set forth. A detailed protocol is presented, based on: 1) presence of clinical and laboratory evidence of infection and its location, and the most likely causing agents involved, 2) bacteriological data on the commonest causing agents of local and systemic infection in burns, and their sensitivity to antibiotics, 3) duration and surface, deepness and location of the burn injury, and 4) spectrum of action, pharmacokinetics, pharmacodynamics and side effects of the various groups of antibiotics, consistent with the age and concomitant diseases of the patients. A number of antibiotic constellations in cases presenting sepsis where resorting to "blind" therapy is necessitated, are recommended. It is underscored that the protocol suggested is open for modifications, and also that antibiotic therapy efficiency may be anticipated only when combined with adequate infusional and operative management.