Electrophysiologic study of dysrhythmias after atrial operations in dogs.

Experiments were conducted with 159 dogs to investigate the mechanism of persistent dysrhythmias clinically encountered after atrial-level operations. Those found after incisions to the internodal pathways (INPs) of the right atrium were analyzed using cardiac mapping in an anesthetized or extracorporeally perfused state. Longitudinal incisions of the posterior INP often allowed inducible sustained atrial flutter, with circus movement of excitation around the right atrium near the tricuspid orfice. Sustained atrial flutter thus produced was modified in cycle length by coexisting division of the middle INP but inhibited by that of the anterior INP. Its incidence increased at chronic stage, with marked cicatricial changes. The disrupted anterior INP markedly prolonged conduction time to the atrioventricular node and A-H interval compared with the other disruptions. Persistent atrioventricular junctional rhythm developed in about 50% of the animals after disruption of all three INPs or anterior and posterior INPs; division of the anterior INP was the common potent factor, although no single blocked INP produced persistent junctional rhythm. Our results support the "summation theory." The incidence of junctional rhythm and hypoxia of the sinoatrial node (flow rate of less than 10 mL.100 g-1.min-1) were markedly enhanced by coexisting blockade of atrial feeding arteries in addition to division of the anterior INP. In conclusion, massive posterior INP disruption is a potent anatomic substrate in producing sustained atrial flutter, middle INP division a modifier, and anterior INP division an inhibitor. Division of the anterior INP is a potent anatomic substrate in producing junctional rhythm, and hypoxia involving the sinoatrial node reacts as its synergic factor.     

Time course of calcium absorption in humans: Evidence for a colonic component

Summary We examined the time course of calcium absorption (CaAbs) in 155 studies, using a double isotope technique. The subjects were 118 healthy peri-menopausal women (mean age 53.3 years), studied as impatients under metabolic balance conditions. We measured the ratio of radiolabeled calcium (oral:IV) in serum and urine for 144 hours after the oral dose, and generated a composite CaAbs curve for all 155 studies using normalized data. Although CaAbs was 80.9% complete at 3 hours, it was still only 95.8% complete at 7 hours; the remaining 4.2% was absorbed in a slower late component, and did not reach completion until about 26 hours. The rapid initial component probably represents mainly small intestinal absorption and the late component, colonic. At the dietary intakes of our subjects, we estimate the size of the late component at about 6.8 mg/day. For fully accurate measurements of CaAbs, it is necessary to allow for this small late component.     

Implantable pacemakers in children.

Permanent pacemakers were implanted in 12 children, ages 2 weeks to 6 years. The cause of the arrhythmia was congenital in three, postoperative in six, viral in one, and unknown in two. One operative death occurred on the second postoperative day. Two late deaths occurred five and 10-1/2 years postoperatively. The late deaths were in patients with good cardiac capture in whom the block followed repair of tetralogy of Fallot. Ventricular arrhythmias were believed to be the cause of death. Reoperation was required 37 times: for pacemaker exhaustion, 17; electrode problems, 15; wound problems, four; and arrhythmia, one. Nine of 12 patients are alive nine months to ten years eight months postoperatively. The remaining three survived for eight to ten years. Frequent reoperation and dilligent correction of defective pacing is rewarded with long, active lives in children requiring implantable pacemakers.     

Evaluation of accuracy in ankle center location for tibial mechanical axis identification.

Many surgical computer-assisted systems use mechanical axis identification as a reference for their computations. The goal of this study was to compare three methods to determine the location of the distal point of the tibial mechanical axis, based on percutaneous digitization of definite anatomical landmarks. In particular, we evaluated the accuracy of the identified tibial mechanical axis and the repeatability of the obtained results. Tests performed by four surgeons on cadaveric knees showed that the variability in identifying the ankle center using two out of the three methods presented introduced an inaccuracy in the mechanical axis identification of around 1 degrees. This makes their use suitable for computer-assisted systems.     

Surgical complications of implanting pacemakers.

An analysis of the complications of implanting pacemakers at St George's Hospital between 1967 and 1973 highlights the difficulties of implanting foreign bodies. During this 7 years 1543 pacemakers were implanted in 779 adults. In 91 patients there were 118 implants with surgical complications, most of them due to a pressure necrosis or local infection; 3 septicaemias occurred. The various complications are classified and related to technique of implantation. Methods of management of the complications are presented. As an Appendix the operative techniques of first and subsequent implantations are outlined.     

Emergency surgery in colonic obstructions. Retrospective study of 70 cases

70 patients with complete colonic obstruction requiring emergency surgery were treated at the "Clinique Chirurgicale C" between 1977 and 1984. Carcinoma was the cause of obstruction in 65 cases. Obstruction was situated on the right colon 8 times, on the splenic flexure 13 times, and on the left colon 49 times. In emergency obstruction of the right colon was treated by right hemicolectomy in 6 cases with 0 death. Obstruction of the splenic flexure was treated in 10 cases by simple loop colostomy, twice by resection with ileo-sigmoid anastomosis, 1 by resection without anastomosis with 5 deaths. Obstruction of the left colon was treated by simple loop colostomy in 46 cases. Of the 34 patients who survived after loop colostomy, 26 were reoperated and in 23 cases a resection could be performed with 2 deaths and the colostomy could be closed in a third stage in 20 cases without death. 5 years survival of curative resection was 57%. It is concluded that primary resection is the best treatment for obstruction of the right colon and of the splenic flexure. But three stage resection seems to be a good procedure for obstruction of the left colon with low mortality, low morbidity and good 5 year survival.     

Primary colonic non-Hodgkin lymphomas: a retrospective clinicopathologic study of 14 cases.

Fourteen cases of primary colonic non-Hodgkin lymphomas (NHL) with a mean age of 51.5 yrs and 64.3% of them female, are reported. While diagnoses were only obtained by cytologic or histopathologic means, 35.5% of the cases were in Stage 1e (S1e) and a further 42.6% in Stage 2e (S2e) and 7.1% in Stage 3e (S3e) according to the modified Manchester classification. 63.9% were of immunoblastic and 21.3% lymphoblastic type according to the Kiel classification. 85.2% of the tumours were located at the caecum. While acute abdomen required surgery in two patients, 85.2% of the series underwent radical interventions. 14.2% were able to receive chemotherapy with a subsequent total morbidity and mortality figures of 21.3% each. It is the authors' argument that prognosis is not solely dependent on the age, sex or the malignancy state of the tumour but more on its infiltrative stage and on the advent of treatment, whether by radical surgery and/or medical means.     

Tumour location is a prognostic factor for survival in colonic cancer patients

Objective To evaluate survival and prognostic factors in a consecutive series of colon cancer patients from a defined city population in Norway. Method All patients with adenocarcinoma of the colon diagnosed between 1993 and 2000 were registered prospectively. Five‐year actuarial survival and 5‐year relative survival rates were calculated. Cox regression analyses were used to study the effect of prognostic factors on survival. Results In the study period 627 patients were admitted. Overall 5‐year relative survival was 50% in females and 52% in males. Five‐year relative survival in 410 (65%) patients operated with curative intent, was 74% for females and 79% for males. Tumour location in the transverse colon, splenic flexure and descending colon (OR = 1.8), emergency operation (OR = 1.7), TNM stage (OR = 1.8–2.9), blood transfusion of more than two units (OR = 1.8) and age (OR = 4.0–7.1) were independent negative prognostic factors. Conclusion Colon cancer located in the transverse and descending colon is associated with poor prognosis. Comparison of results from different centres is difficult due to selection and classification differences, and different methods used for calculation of survival.     

Experimental study of intraperitoneal suramin on the healing of colonic anastomoses.

INTRODUCTION: The effect of the antiangiogenic agent suramin on the healing of colonic anastomoses was studied in a rat model. METHODS: Rats underwent an end-to-end colonic anastomosis and its healing was tested by measuring bursting pressure, hydroxyproline content and number of newly formed vessels. For the bursting pressure experiment suramin was given intraperitoneally in a dose of 200 mg/kg (maximal tolerable dose) and 100 mg/kg. Hydroxyproline content and vessel density were only tested at 100 mg/kg since the toxicity at this dose was lower whereas bursting pressure was still diminished. RESULTS: There were no deaths. On the fourth day after operation bursting pressure in the control group was significantly higher than that in rats treated with suramin 200 mg/kg (P = 0.006) and 100 mg/kg (P = 0.002). Rupture occurred at the anastomotic line. On day 7, this difference was not statistically significant. Four days after the operation, the hydroxyproline content and vessel density were significantly below that in control segments (hydroxyproline: 10.3 versus 7.8 microg per mg dry weight; vessel content: 85.7 versus 49.6 vessels per x 100 field for control and suramin-treated rats respectively). On the seventh day no difference in hydroxyproline levels was seen but the vessel density was still diminished significantly (P = 0.04). CONCLUSION: Experimentally, suramin significantly inhibits and delays healing of colonic anastomoses. Presented in part to the XXXII Congress of the European Society for Surgical Research in Corfu, Greece, May 1997     

An anatomical study of the superficial inferior epigastric vessels in humans.

The lower abdominal skin and fat has become a standard for breast reconstruction in terms of skin texture, suppleness and colour. Concerns regarding donor site morbidity related to the harvest of rectus abdominis musculocutaneous flap, based on the deep inferior epigastric vessels, have turned attention towards alternative options. The superficial inferior epigastric artery (SIEA) flap is a fasciocutaneous flap that has been used for reconstruction of the breast, as well as head, neck and limb defects. In Taylor's classic dissection series the SIEA was 'absent' in 35% [Plast Reconstr Surg 56 (1975) 243]. In our series of 22 cadaver dissections (eight female, three male) the SIEA was identified in 20 and the vein (SIEV) in 21. In 15, the artery was located at the level of the inguinal ligament, within 1 cm of its midpoint. In 17, the origin, from the common femoral artery, was within 2 cm of the inguinal ligament. In 18, the SIEA arose as a common trunk with the superficial circumflex iliac artery, superficial external pudendal artery, and/or the deep circumflex iliac artery. Mean SIEA calibre was 1.9 mm and the mean pedicle length from origin to inguinal ligament was 5.2 cm. Our findings suggest that the SIEA is more consistently present and larger in calibre than previously reported, and consequently may be of greater clinical use than previously believed.     

Experimental study of colonic anastomoses. Comparison of different suture methods in the rat

A comparative experimental study was conducted on three different suture techniques for end-to-end colonic anastomoses. The development of stenosis, perivisceral adhesions and resistance to endoluminal pressure were assessed. The results show that the one layer all-coat interrupted stitch anastomosis displays less resistance to endoluminal pressure during the first seven days but is followed by fewer complications.     

Pancreaticogastrostomy: a further evaluation.

The anastomosis between the remaining pancreas and the intestinal tract after various types of pancreatic resection has been the site of complications responsible for considerable morbidity and mortality. After Whipple resections reestablishment of pancreatic-intestinal continuity has generally been accomplished in some manner between the pancreas and upper jejunum. This suture line has at times failed, often as the result of postoperative pancreatitis, giving rise to hemorrhage, abscess, and fistula formation. Since 1963, 25 patients undergoing pancreaticoduodenal resection have had some portion of their pancreas implanted into the back wall of the stomach. The operations have been done by the resident and senior staff of the Department of Surgery at the University of Pennsylvania. Morbidity has decreased and operative mortality has fallen from 20-30% to 8%. The technique is not difficult and there seems to be less tendency for the anastomosis to leak. Pancreatic function is usually adequate. The procedure is useful after radical resection of the pancreaticoduodenal region or at times after pancreatic trauma.     

Thecaloscopy through sacral bone approaches, cadaver study: further anatomic landmarks.

Endoscopy of the spinal canal, for interventional studies, diagnosis and therapy, is a scientific topic that has attracted the interest of neurosurgeons, anesthesiologists and orthopedic surgeons for the past twenty years. Endoscopy of the thecal sac was assumed to be less important than endoscopy of the ventricular system by neurosurgeons. Nevertheless, during the last years it has attained increasing scientific interest, firstly because of the introduction of small diameter flexible endoscopes and secondly due to the growing interest for minimal invasive diagnostic and therapeutic procedures in modern neurosurgery. Until now thecaloscopy was performed by the ISGT (International Study Group for Thecaloscopy) using co-axial downward orientated approaches. We have examined transsacral approaches to facilitate the navigation of flexible scopes in the lumbosacral subarachnoid space, and thus we now introduce further recognizable endoscopic anatomic landmarks.