Surgeon-specific factors in the acquisition of laparoscopic surgical skills.

BACKGROUND: Training and experience vary widely among surgeons performing laparoscopic surgery (LS). Visual perceptual demands are greater for LS than for traditional surgery, necessitating greater understanding of surgeon variables in skill acquisition and performance. METHODS: During an LS skills course incorporating didactic and simulator-based instruction, 94 surgeons completed an experience/demographic questionnaire, a test of course-specific knowledge acquisition, 10 trials of three dexterity drills, 15 suturing trials using course-specific methods, and 3 standardized tests of visual perception. RESULTS: Age, years posttraining, and visual perception correlated significantly with time required to complete drills and suturing trials (Pearson correlations ranged from r = 0.21, P <0.05, to r = 0.51, P <0.001) even after statistically controlling for variations in knowledge acquisition, which correlated (r = 0.30, P <0.01) with suturing speed. CONCLUSIONS: Surgeon variables play a significant role in speed of acquisition and performance of LS skills. Further studies need to elucidate their role in quality of LS performance.

Experience and visual perception in resident acquisition of laparoscopic skills.

Assess the role of experience and visual perception (VP) in resident acquisition of laparoscopic surgical skills (LSS).Thrity-nine residents (20 PGY-1s tested just before starting residency; 19 PGY 3+) completed an LSS course, including examination of course-specific knowledge before and after didactic tutorials, 10 trials of 3 dexterity drills and suturing, and 3 standardized VP tests.Mean speed increased significantly (p < 0.001) across trials for all dexterity drills and suturing. Senior residents performed suturing trials 1 to 4 significantly faster (p < 0.05) than did PGY 1's (M +/- SD averaged across trials 1 to 4: 166.5 +/- 59.9 vs 252.3 +/- 108.2 seconds, p < 0.01). Group differences on later trials were progressively smaller and nonsignificant, as were all group differences on dexterity drills. Significant correlations between VP and speed on drills ranged from (r = -0.41, p < 0.01) to (r = -0.71, p < 0.001). Visual perception did not correlate significantly with suturing speed; neither pretest nor posttest scores correlated significantly with drill or suturing speeds.Residents at all levels can significantly increase LSS performance speed to comparable levels during a brief intensive skills course. Proficiency in specific aspects of VP is directly associated with performance speed on dexterity drills, shown in previous studies to be fundamental in the development of intracorporeal suturing skill. (Curr Surg 57:368-372. Copyright 2000 by the Association of Program Directors in Surgery.)

M(mu-CN)Fe(mu-CN)M' chains with phthalocyanine iron centers: preparation, structures, and isomerization.

The molecular building blocks Fe(II)Pc (Pc = phthalocyaninato2-), Fe(III)Pc, ZnPc, Cp(dppe)Fe, and Cp(PPh3)2Ru were combined in the cyanide-bridged dinuclear reference compounds with M-CN-ZnPc and M-CN-FePc-CN arrays containing Fe(II)Pc and Fe(III)Pc. The linear trinuclear species with the M(mu-CN)Fe(mu-CN)M' backbone were prepared for both Fe(II)Pc and Fe(III)Pc centers, for terminal Fe/Fe, Fe/Ru, and Ru/Ru combinations and for all three possible cyanide orientations (M-CN-Fe-NC-M', M-CN-Fe-CN-M', and M-NC-Fe-CN-M'). The 15 complexes obtained were identified from their IR spectra and six structure determinations. The preferred orientation of the cyanide bridges could be established starting from the [Fe-NC-Fe(III)Pc-CN-Fe]+ complex, which is labile in solution and isomerizes to the corresponding [Fe-CN-Fe(III)Pc-NC-Fe]+ complex. A kinetic analysis of this isomerization has yielded an activation barrier of roughly 110 kJ/mol.

M(mu-CN)Fe(mu-CN)M' chains with phthalocyanine iron centers: redox, spin-state, and mixed-valence properties.

Dinuclear complexes with M-CN-ZnPc and M-CN-FePc-CN arrays and trinuclear complexes with M(mu-CN)Fe(mu-CN)M' arrays containing central metal phthalocyaninato (Pc) and external Cp(dppe)Fe or Cp(PPh3)2Ru building blocks (M) and having all possible orientations of the bridging cyanide ligands were subjected to electrochemical and preparative redox reactions. The species with unpaired electrons show characteristic MMCT bands in the near-IR spectra, the energies of which depend in a typical fashion on the nature of the building blocks and the orientation of the cyanide bridges and can be correlated with the redox potentials. Cyclic voltammetry has revealed electronic communication between the external organometallic units. An analysis of the MMCT spectra allows the assignment of the odd-electron complexes as class II mixed-valence species. The magnetic moments of the complexes with central Fe(III)Pc units are characteristically higher than the spin-only value for one unpaired electron. A Mössbauer investigation has shown that the M-CN-Fe(III)Pc-NC-M complexes undergo a low-spin-to-high-spin crossover of the Fe(III) component above room temperature.

Psychoneuroimmunological correlates of persisting sciatic pain in patients who underwent discectomy.

Patients suffering from persisting sciatic pain 8 weeks following discectomy were compared with patients displaying low complaints and healthy, pain-free volunteers regarding their interleukin-6 (IL-6) levels, morning cortisol levels and degree of psychological distress. Whereas serum concentrations of IL-6 were measured by collecting blood samples between 0945 and 2400 h in intervals of 45 min, morning cortisol levels were obtained by sampling saliva on five ensuing measurements, beginning immediately after awakening. In addition, questionnaires aimed at measuring depressive mood, somatic symptoms, coping and chronic stress were filled out by the subjects. The patients with ongoing pain displayed significantly elevated IL-6 levels and an attenuated elevation of cortisol secretion after awakening compared to the two other groups. Patients with persisting pain were also suffering more frequently from depressive mood and ongoing work-related strains. In addition, maladaptive coping strategies were favoured by these patients. The presented data support the hypothesis that the persistence of pain in many of the concerned patients may significantly be related to dysfunctional reciprocal relations between neural, endocrine and immune function.

Entrapment of small bowel after laparoscopic herniorrhaphy.

As laparoscopic hernia repair continues to evolve as an operative procedure, papers will continue to be published discussing new variations and new techniques which will better the operative procedure as a whole and quite possibly decrease its associated complications (i.e., morbidity and mortality). We present a case of laparoscopic bilateral herniorrhaphy in which after uncomplicated surgery and an immediate, uneventful postoperative course, the patient returned to our institution with both a rectus sheath hematoma and small bowel obstruction. The patient, who was initially treated conservatively, ultimately required laparotomy for persistent small bowel obstruction. Laparotomy revealed incarcerated small bowel in a cavity between the posterior rectus fascia and the rectus muscle proper. The patient did well after laparotomy and was discharged home with no further complications.

Model of intestinal continence using an implantable pulse generator and a myoprosthetic sphincter.

Past attempts at artificial continence using a wide range of surgical procedures and devices have met with only limited success because of excessive rates of infection, rejection, incomplete continence, and technical difficulty. Presented here is a model of artificial continence using a lumen-occluding Teflon loop powered by the rectus abdominus muscle and activated by an implantable pulse generator. Eight female mongrel dogs underwent laparotomy with creation of a Brooke ileostomy and insertion of a hand-tooled Teflon band around the ileum. The free ends of the loop were sutured, under tension, to the posterior rectus sheath creating extrinsic compression of the bowel by the tightened loop. After denervation of the rectus, stimulating electrodes were implanted and connected to a transcutaneously activated pulse generator (Medtronic SE-4). Stimulation caused contraction of the muscle segment. As the free ends of the prosthetic sling approach each other, the occlusive band loosens, resulting in free drainage of intestinal contents and reduction in intraluminal pressure of the proximal ileum. Withdrawal of current allows for relaxation and return of the muscle to its resting length; this reoccludes the bowel. At 2 weeks, all dogs were continent to solid matter and all but two were continent to liquids. Two dogs developed wound infections requiring drainage. Signal attenuation across the skin resulted in total uncontrollable continence in two dogs because of an inability to transfer sufficient current to the muscle. Direct probe stimulation by an external pulse generator resulted in drainage in these dogs. Necropsy showed no evidence of bowel ischemia in any of the specimens examined at 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheter fracture and embolization in a totally implanted venous access catheter.

A totally implanted venous access system was placed in a 24-year-old male patient with Hodgkins disease for chemotherapy. Twelve months after implantation it was noted on chest x-ray that the catheter had fractured and the distal fragment embolized to the right ventricle. Catheter separation and embolization is a recognized but uncommon complication of Hickman catheters. It is an even rarer complication of implanted central venous catheters. With the increasing use of these new venous access systems this complication may become a more prevalent, but an avoidable complication.

Placement of an implantable percutaneous permanent triple-lumen catheter.

A new technique has been described for the placement of an implantable percutaneous triple-lumen catheter. This procedure eliminates the need for a large bore introducer. It also provides a mechanism to change these catheters over a wire if necessary. This cannot be accomplished with the Hickman or Broviac catheters. The three lumens allow multiple, simultaneous intravenous therapies to be administered in the long-term inpatient, as well as the outpatient.

Sclerosing cholangitis, chronic pancreatitis, and Sjogren's syndrome: a syndrome complex.

The disease complex of chronic pancreatitis, sclerosing cholangitis, and Sjogren's syndrome seems to be a well-defined entity with an autoimmune cause similar to that which occurs in primary biliary cirrhosis. Treatment depends on the component of primary sclerosing cholangitis and, more particularly, on the degree of extrahepatic involvement.

CT diagnosis of fecaloma.

The diagnosis of fecaloma can occasionally be difficult. A case is presented in which computed tomography was valuable in making the diagnosis.

The problem of liver metastasis.

The detection and management of tumors metastatic to the liver is still unsettled. The uniformly poor prognosis only underlines the need to diagnose and treat the primary malignant lesion earlier, before systemic metastases lodge in the liver, lung or brain. Serologic markers are not specific or sensitive enough although when used serially they may follow the course of some tumors. The exciting advances in radiologic diagnosis have allowed a more accurate and pictorial representation of disease, exciting cross-sectional views but not earlier diagnosis. The use of scans and ultrasound as a screening measure is investigational only as there is not good evidence to support this as a routine screening test. The treatment of hepatic metastases is also insoluble. For primary lesions that are controlled surgically and whose natural history is measured in years (not months) a more aggressive approach is justified. Lesions confined to one lobe, particularly single lesions, lend themselves to resection. Segmental or wedge resection is the equal of formal hepatic lobectomy and is safer for patients and surgeons. For most patients (70 to 85 percent) operation is not a reasonable choice. How does one select from no therapy, intravenous chemotherapy, intraarterial chemotherapy (implantable pumps, infusion plus embolization) or hepatic artery embolization? These decisions are not easily reached. Institutional enthusiasm is as much a reflection of local expertise and biases as are meaningful data. There are responders to all of these methods, but few long-term survivors. Side effects that limit life style and activity detract from some of the remaining days. Today patients share in the decision-making process. Their own biases are frequently in discord with the treating physician's. When this exists and data do not support one treatment method we acquiesce to the patient's wishes and use his or her experience to increase our data base. Intraarterial chemotherapy is making a strong impact, objective information not withstanding. Unless an implantable pump is covered by third party payments we prefer a "test trial" of several monthly intraarterial injections of chemotherapy to see if a positive effect occurs. Intravenous chemotherapy remains our therapeutic choice particularly if part of a trial. If there is no response and side effects are severe, we prefer to withdraw treatment.

Another facet of Mirizzi's syndrome.

Mirizzi's syndrome is a rare entity of common hepatic duct obstruction that results from an inflammatory response secondary to a gallstone impacted in the cystic duct or neck of the gallbladder. It results from an almost parallel course and low insertion of the cystic duct into the common hepatic duct. In a variant of Mirizzi's syndrome, the cause of the common hepatic duct obstruction was a primary cystic duct carcinoma rather than gallstone disease.

Evaluation of unaccountable phlebitis with the long arm silastic catheter.

This study was initiated to identify the causal factor responsible for the development of "unaccountable phlebitis" when using the long arm silastic catheter. Use of computerized axial tomography has provided a means of analyzing veins containing indwelling silastic catheters of the upper arm. Physical data of diameters of the veins are limited to inaccuracies of the machine and must only be regarded as relative. We have been able to detect a great variability of cross-sectional vein diameter and area within any one patient. This narrowing tends to occur in the mid-upper arm region and may explain the occurrence of "unaccountable" phlebitis in this area. It appears that laminar blood flow and flotation of the catheter in the vein is inhibited in these areas of narrowing.

Toxic megacolon complicating Crohn's colitis.

Toxic megacolon complicating ulcerative colitis has been a well-recognized entity since its original description in 1950. The presence of toxic megacolon frequently has precluded a diagnosis of Crohn's colitis. Recent literature, however, has demonstrated that the incidence of toxic megacolon associated with Crohn's colitis (4.4-6.3%) may be higher than that in ulcerative colitis (1-2.5%). Differentiation between these two catastrophic forms of colitis is important in respect to prognosis and long-term results. Medical management of toxic megacolon may be initially successful in either type of colitis. Surgical intervention is indicated if the patient's condition does not improve within 48-72 hours. A subtotal colectomy with an ileostomy and mucous fistula is probably the treatment of choice for most of these extremely ill patients. The influence of the type of colitis on the results of subsequent management of the rectal stump remains unresolved.