Biomedical subjects
Publications and source records attributed to W H Chapman.
The first robotic Nissen fundoplication using the da Vinci robotic surgical system was performed on a 56-year-old woman with a 20-year history of severe gastroesophageal reflux disease refractory to medical management. The recovery was uneventful, and follow-up continues.
OBJECTIVE: To detail robotic procedure development and clinical applications for mitral valve, biliary, and gastric reflux operations, and to implement a multispecialty robotic surgery training curriculum for both surgeons and surgical teams. SUMMARY BACKGROUND DATA: Remote, accurate telemanipulation of intracavitary instruments by general and cardiac surgeons is now possible. Complex technologic advancements in surgical robotics require well-designed training programs. Moreover, efficient robotic surgical procedures must be developed methodically and safely implemented clinically. METHODS: Advanced training on robotic systems provides surgeon confidence when operating in tiny intracavitary spaces. Three-dimensional vision and articulated instrument control are essential. The authors' two da Vinci robotic systems have been dedicated to procedure development, clinical surgery, and training of surgical specialists. Their center has been the first United States site to train surgeons formally in clinical robotics. RESULTS: Established surgeons and residents have been trained using a defined robotic surgical educational curriculum. Also, 30 multispecialty teams have been trained in robotic mechanics and electronics. Initially, robotic procedures were developed experimentally and are described. In the past year the authors have performed 52 robotic-assisted clinical operations: 18 mitral valve repairs, 20 cholecystectomies, and 14 Nissen fundoplications. These respective operations required 108, 28, and 73 minutes of robotic telemanipulation to complete. Procedure times for the last half of the abdominal operations decreased significantly, as did the knot-tying time in mitral operations. There have been no deaths and few complications. One mitral patient had postoperative bleeding. CONCLUSION: Robotic surgery can be performed safely with excellent results. The authors have developed an effective curriculum for training teams in robotic surgery. After training, surgeons have applied these methods effectively and safely.
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Appendiceal mucocele is a rare entity with a nonspecific preoperative presentation and is diagnosed intraoperatively in a majority of cases. The emphasis lies in accurate pathologic diagnosis, as the final treatment can differ depending on the malignant potential. The case presented was correctly diagnosed preoperatively. Laparoscopic exploration was both diagnostic and therapeutic. This case demonstrates the utility and safety of laparoscopy in the treatment of appendiceal masses.
The role of minimally invasive surgery continues to expand in all the specialties and subspecialties of surgery. At one time, obesity and pregnancy were considered a relative contraindication to laparoscopic surgery. With improved technology and skills, surgeons are able to operate on patients who were once considered to be at too high a risk for laparoscopic surgery. Herein, laparoscopic splenectomy performed at the time of Caesarean section is reported. This case demonstrates the safety and efficacy of laparoscopic splenectomy in a morbidly obese female in the immediate postpartum time.
The GORE (W.L. Gore & Associates, Phoenix, AZ) Suture Passer, a new reusable fascial closure device, is one of the best devices on the market for closure of laparoscopic trocar site wounds. The technique for closure of fascia using this device is described. It is a cost-effective, safe, and easy.
OBJECTIVE: This study was done to determine the potential benefits of minimally invasive mitral surgery performed with intraoperative video assistance. METHODS: From May 1996 until March 1997, a minithoracotomy and video assistance were used in 31 consecutive patients undergoing mitral repair (n = 20) and replacement (n = 11). Their ages ranged from 18 to 77 years (59 +/- 2.6 years; mean +/- standard error of the mean). Ejection fractions were 35% to 62% (55% +/- 1.5%). Operations were done with either antegrade/retrograde (n = 10) or antegrade (n = 19) cold blood cardioplegia and a new transthoracic crossclamp or with ventricular fibrillation (n = 2). Peripheral arterial cannulation (n = 28) and pump-assisted right atrial drainage (n = 26) were used most often. RESULTS: No hospital deaths occurred, but the 30-day mortality was 3.2%. Complications included deep venous thrombosis and a phrenic nerve palsy in one patient each. No patient had a stroke or required reoperation for bleeding. Postoperative echocardiography showed excellent valve function in all but one patient. Cardiopulmonary bypass and arrest times averaged 183 +/- 7.2 and 136 +/- 5.5 minutes, respectively. Compared with 100 patients having conventional mitral valve operations, these patients had significantly shorter hospitalization times (8.6 +/- 0.5 vs 5.1 +/- 0.9 days, p = 0.05). Moreover, 81% of the later cohort were discharged between day 3 and 5 (3.6 +/- 0.2 days). Hospital charges (decreases 27%, p = 0.05) and costs (decreases 34%, p < 0.05) were less than in conventional operations. Patient follow-up suggested minimal perioperative pain and rapid recovery. CONCLUSIONS: Early results suggest that video-assisted minimally invasive mitral operations can be done safely. These methods may benefit patients through less morbidity, earlier discharge, and lower cost.
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A 35-year-old, previously healthy woman, known to be thyrotoxic, was transferred from a community hospital for "acute abdomen." Abdominal pain, distention, and hyperemesis resolved with placement of nasogastric tube (NGT) and return of 2,600 mL of bilious fluid. Continued high NGT output made oral or NGT administration of antithyroid drugs impossible. We gave propylthiouracil (PTU) by retention enemas with therapeutic serum levels and sublingual saturated solution of potassium iodide (SSKI) with 70% absorption based on 24-hour free iodine urinary excretion. The patient's thyroxine (T4) and triiodothyronine (T3) radioimmunoassays were normal on hospital days 10 and 12, respectively. However, free T4 and T3 resin uptake did not normalize until hospital day 31. On hospital day 32, she tolerated removal of NGT without nausea and 4 days later was taking a regular diet. We conclude that our patient's gastrointestinal symptoms were a prominent feature of her thyrotoxicosis and that rectal PTU and sublingual SSKI are effective in administration of antithyroid drugs.
It has been reported that His-119 of ribonuclease A plays a major role as an imidazolium ion acid catalyst in the cyclization/cleavage of normal dinucleotides but that it is not needed for the cyclization/cleavage of 3'-uridyl p-nitrophenyl phosphate. We see that this is also true for simple buffer catalysis, where imidazole (as in His-12 of the enzyme), but not imidazolium ion, plays a significant catalytic role with the nitrophenyl substrate, but both are catalytic for normal dinucleotides such as uridyluridine. Rate studies show that the enzyme catalyzes the cyclization of the nitrophenylphosphate derivative 47,000,000 times less effectively (kcat/kuncat) than it does uridyladenosine, indicating that approximately 50% of the catalytic free energy change is lost with this substrate. This suggests that the nitrophenyl substrate is not correctly bound to take full advantage of the catalytic groups of the enzyme and is thus not a good guide to the mechanism used by normal nucleotides. The published data on kinetic effects with ribonuclease A of substituting thiophosphate groups for the phosphate groups of normal substrates has been discussed elsewhere, and it was argued that these effects are suggestive of the classical mechanism for ribonuclease action, not the novel mechanism we have recently proposed. The details of these rate effects, including stereochemical preferences in the thiophosphate series, can be invoked as support for our newer mechanism.
We have used a combination of spectroscopic, calorimetric, and computational techniques to characterize the properties of nucleic acid complexes with 2',5''- and 3',5''-phosphodiester linkages. Specifically, we have compared the properties of complexes formed by the association of 3',5'' single-stranded 16-mers of adenylic acid (A16) and thymidylic acid (T16) with the complexes formed by the corresponding single-stranded 16-mers with 2',5''-phosphodiester linkages (A*16 and T*16). Our results reveal the following differential features: (i) the 3',5'' strands form either a duplex or a triplex, depending on the sodium ion concentration, whereas the 2',5'' strands form either a triplex or no complex at all; (ii) the 2',5'' and 3',5'' triplexes exhibit significantly different CD spectra, suggesting that the two triplex states are conformationally nonequivalent; (iii) the 2',5'' triplex has a lower charge density than the 3',5'' triplex; (iv) the thermal stability of the 3',5'' triplex, as expected, is concentration dependent, whereas the thermal stability of the 2',5'' triplex is concentration independent; (v) relative to their component single strands, the 2',5'' triplex is thermodynamically much less stable than the 3',5'' triplex, despite being thermally more stable; (vi) the reduced thermodynamic stability of the 2',5'' triplex relative to the 3',5'' triplex is overwhelmingly enthalpic in origin. In the aggregate, our results reveal and characterize significant differences in the properties of complexes formed by the association of strands with identical base sequences but different phosphodiester linkages. We describe a structural model that is consistent with many of the differential properties observed. We also speculate on how these differential properties may have provided an evolutionary advantage for 3',5'' linkages and how the properties of 2',5'' complexes might be exploited in antisense strategies.
Femoral hernias are of very rare occurrence at any age, but are exceedingly rare in the pediatric population. A 10-year survey, 1979-1989, of our experience with pediatric hernias produced a total of 1,134 inguinal hernias and 6 femoral hernias, supporting an incidence of 0.5% for femoral hernias in our population. The correct diagnosis was made in only two cases preoperatively. These two patients had undergone inguinal herniorrhaphies less than 6 months prior to presenting with recurrent groin masses. Femoral hernias were most frequently misdiagnosed as inguinal hernias. Inclusion of this entity in the differential diagnosis of groin masses, an accurate preoperative physical exam, and a careful surgical exploration will allow one to make the correct diagnosis and prevent unnecessary reoperations. In addition, early recurrence of a groin mass after inguinal exploration and herniorrhaphy should make one suspicious of a femoral hernia. At surgery, our recommendations include a simple infra-inguinal exploration medial to the femoral vessels when an inguinal hernia is unexpectedly not found at groin exploration and a Cooper's ligament repair when a femoral hernia is encountered. All six cases in our review were repaired with Cooper's ligament repair without complication.
A case of pulmonary embolism from a venous thrombosis distal to the popliteal vein is reported. This occurred despite venographic and ultrasound verification that the thrombus had not extended to the popliteal vein. The medical literature supports expectant treatment of "calf-only" venous thrombi. Our case clearly demonstrates that clinically significant pulmonary emboli can arise from calf vein thrombi without popliteal involvement.
Thirty-four patients have completed treatment on a bladder-preservation protocol using primary irradiation combined with infusion 5-fluorouracil (5-FU). 4,000 cGy pelvic irradiation was delivered in 5 weeks, with 1,000 mg/m2/day of 5-FU administered as a 96 hr infusion on days 1-4 of week 1 and 4. After a 3-week rest period, patients eligible for cystectomy underwent cystoscopy and biopsy. Those with residual tumor underwent cystectomy, and those without tumor received an additional cycle of chemotherapy and irradiation. Patients ineligible for cystectomy for reasons medical, surgical, or refusal received a third cycle without the 4-week delay or re-evaluation. With a median follow-up of 18 months (range 2-45 months), and with 25/34 patients having T3 (16) or T4 (9) tumors, 17 patients are NED, 4 have died of intercurrent deaths, 7 have died with bladder cancer, and 6 are alive with tumor (2 confined to the bladder). The actuarial cancer-specific survival for the entire group of patients is 64% (+/- 12%) at 45 months, with a freedom from relapse of invasive cancer of 54% (+/- 10%). Twenty-four of the 34 patients retained intact bladders, with 20/24 reporting entirely normal voiding. Of 18 potential surgical candidates, 13/16 (81%) who underwent pathologic re-staging after 2 cycles of chemoradiotherapy had no histologic evidence of residual cancer. Of these 13 patients, 8 remain NED and 2/13 have locally recurrent non-invasive tumors only. Treatment was well-tolerated, with 28/34 patients having received 100% of the planned 5-FU and 34/34 having received greater than 80%. This regimen appears more successful than radiotherapy alone in achieving complete tumor responses, and is an attractive alternative for patients who are unable to receive more aggressive chemotherapy/radiation combinations.
Gonadoblastoma, a rare gonadal neoplasm, presents most frequently in phenotypic female or phenotypically male patients with dysgenetic gonads or undescended testes. To date, only 2 cases of gonadoblastoma have been reported in anatomically normal male patients with scrotal testes. Both of these patients presented with testicular masses and germ cell tumors. We report a case of a genotypically and phenotypically normal, fertile man with descended testes who on evaluation for chronic orchialgia had a gonadoblastoma unaccompanied by a germ cell neoplasm. The tumor was nonpalpable and was initially discovered on scrotal ultrasound.
Urethral catheterization, the standard method for measurement of bladder volume, is associated with patient discomfort plus the risks of urethral trauma and urinary tract infection. A portable ultrasound instrument that automatically determines bladder volume was used for 164 determinations and the digital readout correlated with the catheterized volume (r2 equals 0.79). This instrument is a noninvasive alternative to urethral catheterization for the determination of bladder volume in most patients.
A simple method of vasovasostomy using a unique hollow, biflanged, hydrolyzable, self-retaining intraluminal stent made of polyglycolic acid (PGA) was evaluated in rat and dog animal models. The stented vasovasostomy was compared with a modified two-layer technique in a randomized prospective trial in rats. Twenty of 22 vasovasostomies using the 0.8890 mm and 0.9398 mm stents were patent, whereas only 4 of 22 vasovasostomies using a modified two-layer anastomosis without a stent were patent (P less than 0.01). Eight dogs underwent implantation of the absorbable vasovasostomy stent on one side and two-layer vasovasostomy on the other. Scanning electron microscopy showed superior re-epithelialization and closer return to normal morphology in the stented vasovasostomies than with the conventional two-layer technique.
We discuss 14 children and adolescents with myelodysplasia who underwent bladder augmentation with the ileocecal segment. The bowel was not detubularized nor was the ileocecal valve intussuscepted. Urodynamic evaluation was performed before and after the procedure in 13 patients with a followup of 1 to 8 years. Postoperative capacity and compliance were normal but cecal contractions occurred in 8 patients despite adequate doses of anticholinergics. Reflux was demonstrated at capacity with a cecal contraction in 4 patients but upper tract dilatation and infection were not clinical problems. Three patients required reoperation for complications owing to ureteroileal stenosis and/or urinary tract calculi. Although the clinical results were satisfactory, detubularized segments of bowel with intussuscepted afferent loop valves to prevent reflux may resolve these problems in the future.