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Biomedical subjects

Michael Woods

Publications and source records attributed to Michael Woods.

11 recordsLinked to original sources
PubMed2006

Transperitoneal versus extraperitoneal robotic-assisted radical prostatectomy: is one better than the other?

OBJECTIVES: To evaluate the differences, if any, in outcomes with transperitoneal (TP) versus extraperitoneal (EP) approaches during robotic-assisted radical prostatectomy (RARP). METHODS: We reviewed the data from 40 consecutive patients who underwent EP-RARP at our institution by the same surgical team. The outcomes were compared with those of 40 consecutive patients who underwent TP-RARP performed by the same team in a nonrandomized manner. The operative and postoperative parameters (total operative time, estimated blood loss, length of stay, robotic console time, and robotic anastomosis time), as well as complications and surgical margin status, were analyzed and compared. RESULTS: The patient demographics were similar in both groups. Nerve sparing was performed in 35 and 36 patients in the TP and EP groups, respectively. Pelvic lymphadenectomy was performed in 14 and 12 patients in the TP and EP groups, respectively. The operative time was slightly longer with the TP approach at 236 minutes (range 111 to 360) compared with 229 minutes (range 143 to 382) in the EP group, but the difference was not statistically significant (P = 0.5722) between the two groups. Also, the differences in robot console time, anastomosis time, estimated blood loss, and length of stay were not statistically significant between the two groups at the 5% significance level. The complication and positive surgical margin rates were similar in both groups. CONCLUSIONS: As expected, the EP approach is feasible with RARP. Our data suggest that the EP approach is comparable to the TP approach and produces favorable outcomes. Surgeon preference will likely play a significant role in the approach used.

Aged↗
PubMed2006

Robotics in urologic surgery: an evolving new technology.

Rapid technological developments in the past two decades have produced new inventions such as robots and incorporated them into our daily lives. Today, robots perform vital functions in homes, outer space, hospitals and on military instillations. The development of robotic surgery has given hospitals and health care providers a valuable tool that is making a profound impact on highly technical surgical procedures. The field of urology is one area of medicine that has adopted and incorporated robotic surgery into its armamentarium. Innovative robotic urologic surgical applications and techniques are being developed and reported everyday. Increased utilization and development will ultimately fuel the discovery of newer applications of robotic systems in urologic surgery. Herein we provide an overview of the history, development, and applications of robotics in surgery with a focus on urologic surgery.

Equipment Design↗
PubMed2006

A clinical comparison between nickel titanium springs and elastomeric chains.

OBJECTIVES: To compare the rates of maxillary canine retraction and molar anchorage loss when using either NiTi springs or elastomeric chains delivering a known force with sliding edgewise mechanics. METHODS: Twelve patients who required maxillary canine retraction into first premolar extraction sites as part of their orthodontic treatment were selected. In a split-mouth design, these patients received precalibrated NiTi springs (112 quadrants) and pre-measured elastomeric chains (12 quadrants), all delivering initial forces of approximately 200 g and being reactivated at 28 day intervals. Space closure and forward movement of the maxillary first molars were evaluated using maxillary impressions, which were taken before the start of canine retraction and then at 28 day intervals until canine retraction was almost complete. RESULTS: Statistical analysis revealed that the mean rate of space closure with NiTi springs (1.85 mm/month) was only 0.17 mm/month greater (p = 0.011) than that produced with the elastomeric chains (1.68 mm/month). The mean rates of anchorage loss for the NiTi springs and elastomeric chain were 0.46 mm/month and 0.45 mm/month respectively. This difference was not statistically significant. These amounts of forward molar movement were calculated to be between one quarter and one third of the average space closure per month, even in the presence of a fixed transpalatal arch. CONCLUSION: The results indicate that the rates of space closure and molar anchorage loss using either NiTi springs or elastomeric chains, if reactivated every 28 days, are likely to be similar.

Adolescent↗
PubMed2005

The mandibular muscles and their importance in orthodontics: a contemporary review.

It is widely accepted that the orthodontist should have a thorough understanding of the craniofacial musculature and its association with the growth and development of the dentofacial complex. There is still much controversy regarding the influence of the mandibular muscles on normal growth and development, and on orthodontic treatment and stability. This review presents an outline of the mandibular muscles and the vertical facial pattern. The different methods by which the mandibular muscles have been investigated are discussed. The potential influence of these muscles on normal morphologic variation in different people is also discussed, along with the implications for contemporary orthodontic treatment and stability.

Bite Force↗
PubMed2005

Technical modifications for robot-assisted laparoscopic pyeloplasty.

PURPOSE: Laparoscopic pyeloplasty (LP) is gaining acceptance as a standard of care for the repair of ureteropelvic junction (UPJ) obstruction, with results comparable to those of open repair. However, it remains a technically challenging procedure requiring intracorporeal suturing skills. Recent reports have demonstrated equally effective results with robot-assisted laparoscopy with shorter operative times. We present our modified technique for daVinci robot-assisted LP. PATIENTS AND METHODS: From November 2002 to May 2004, 32 consecutive patients underwent LP with the daVinci robotic system for UPJ obstruction. Just prior to laparoscopy, 31 patients underwent retrograde pyelography and cystoscopic placement of a ureteral catheter just distal to the UPJ, which was prepared into the operative field. The remaining patient had an indwelling stent placed preoperatively. Three transperitoneal ports are placed for the robot. A fourth port is placed for retraction, suction, dissection, and suture passage by the bedside surgeon. This port was placed at McBurney's point in the first two patients and the subxiphoid area in the subsequent 30 patients. A ureteral stent was inserted retrograde intraoperatively with laparoscopic assistance after exchanging the ureteral catheter for a guidewire. A Jackson-Pratt drain was placed in all cases. RESULTS: All procedures were completed laparoscopically. Anderson-Hynes dismembered pyeloplasty was performed in 31 patients, while Fengerplasty was performed in 1 patient. The average operative time was 300 minutes (initial 12 procedures: 384 minutes; last 10 procedures: 197 minutes). The average blood loss was approximately 50 mL and the average hospital stay 1.1 days. A crossing vessel was present in 44% of the cases. Stone extraction was performed in 5 cases (23%) and kidney biopsy in 1 case. The only perioperative complications were one migrated stent, which was repositioned under sedation without sequelae and one urinary tract infection. Of the 18 patients with follow-up exceeding 6 months (average 10.3 months), 16 have improved drainage and function and are asymptomatic. One patient with flank pain has no evidence of obstruction. One with delayed, although improved, drainage is asymptomatic. CONCLUSIONS: The daVinci robot system can be used effectively for LP. Although initial operative times were long, there was a significant decrease after the first 12 cases. Having retrograde access to the ureter allows simple intraoperative stent placement. We found that the subxiphoid placement of the fourth port gave the bedside surgeon the optimal location for suction, dissection, and intracorporeal suture passage. This approach and technique have become standard in our treatment of UPJ obstruction.

Adolescent↗
PubMed2005

Robotic assisted laparoscopic pyeloplasty in children.

PURPOSE: Historically, open pyeloplasty has been the gold standard of treatment for ureteropelvic junction obstruction in the pediatric age group. The prospect of using technology such as the robot in this age group has been a concern. Several non-urological robotic procedures have been performed in children. We undertook a retrospective study to evaluate the feasibility and outcomes of robotic assisted laparoscopic pyeloplasty in the pediatric population. MATERIALS AND METHODS: Seven patients 6 to 15 years old underwent robotic assisted laparoscopic pyeloplasty at our institution between June 2003 and November 2004. All patients underwent dismembered pyeloplasty (Anderson-Hynes). Variables analyzed included length of stay, estimated blood loss, operative time, anastomosis time and docked robotic time. RESULTS: Mean followup was 10.9 months (range 2 to 18). Mean length of stay was 1.2 days (range 1 to 3). Mean operative time was 184 minutes (range 165 to 204), with a mean robotic anastomosis time of 39.5 minutes (30 to 46). Mean estimated blood loss was 31.4 ml (range 10 to 50). Stent size varied from 3.8Fr to 6Fr. Six of the 7 patients have had followup studies demonstrating improved drainage, symptom resolution and no evidence of obstruction on diuretic renal scans or excretory urogram. The remaining patient is awaiting 3-month followup evaluation. CONCLUSIONS: Robotic assisted pyeloplasty can be safely performed in the pediatric population. The precision in dissection, incision and suturing allows for comparable results to open pyeloplasty in this age group.

Child↗
PubMed2004

Laparoscopic partial nephrectomy of solid renal masses without hilar clamping using a monopolar radio frequency device.

PURPOSE: Partial nephrectomy is currently recommended for most amenable solid renal tumors, especially if they are exophytic and less than 4 cm. We reviewed our initial experience with laparoscopic partial nephrectomy for solid renal masses without clamping the renal vasculature using a monopolar device that uses radio frequency energy with low volume saline irrigation for simultaneous blunt dissection, hemostatic sealing and coagulation of the renal parenchyma (TissueLink, TissueLink Medical, Inc., Dover, New Hampshire). MATERIALS AND METHODS: From September 2002 to April 2003, 10 patients underwent transperitoneal laparoscopic partial nephrectomy, including 9 with solid renal masses and 1 with a complex cyst. In all cases the renal hilum was dissected and the renal vessels were isolated but none had renal vascular clamping. The TissueLink DS dissecting sealer or Floating Ball (TissueLink Medical, Inc.) was used to dissect the tumor free bluntly, while simultaneously sealing and coagulating bleeders. RESULTS: Mean patient age was 54.6 years (range 42 to 72). Mean American Society of Anesthesiologists score was 2.3 (range 2 to 4). Mean tumor size was 3.9 cm (range 2.1 to 8). The mass had a peripheral location in 7 cases and a central location in 3. Mean operative time was 232 minutes (range 144 to 280) and mean blood loss was 352 ml (range 20 to 1000). One patient received blood transfusion and all tumor margins were negative. Mean hospital stay was 1.7 days (range 1 to 5) and pain medication use was minimal. One patient had a brief period of urine leakage from the lower pole calix, which was managed successfully by ureteral stenting and Foley catheter drainage of the bladder. CONCLUSIONS: Laparoscopic partial nephrectomy can be performed without renal vascular clamping. TissueLink technology allows complete tumor resection and provides adequate parenchymal hemostasis of the tumor bed. Its scant tissue charring production does not interfere with the pathological assessment of the tumor margin status.

Adult↗
PubMed2002

And hemolysis goes on: ventricular assist device in combination with veno-venous hemofiltration.

BACKGROUND: Ventricular Assist Device (VAD) is an accepted treatment as a bridge to cardiac transplantation, and may be of help in patients as destination therapy for end-stage cardiac failure. The low output state associated with end-stage cardiac failure predisposes patients to renal dysfunction and the need for short-term renal support. The use of cardiopulmonary bypass for VAD insertion, VAD, and hemofiltration expose the blood to mechanical trauma and activated inflammatory cascades that can result in hemolysis. This produces free hemoglobin, a known nephrotoxin; this is a further renal insult. This study assesses the effect of VAD alone and in combination with continuous veno-venous hemofiltration (CVVHF) on hemolysis. METHODS AND RESULTS: From July 1999 to December 2000, Thoratec VAD was used in 11 patients. Nine (all males) were included in this study as all had laboratory profiles. Hemolysis was quantified by plasma free hemoglobin (PFHb) and hydroxybuterate dehydrogenase (HBD) levels measured daily, defined as PFHb level greater than 40 mg/L and HBD greater than 250 IU/L. Data relate to the following time intervals while the VAD was still in situ: T1 = 24 hours post-VAD insertion, T2 = 24 hours post-CVVHF start, T3 = 48 to 72 hours with the same CVVHF circuit, T4 = 24 hours post-stopping of CVVHF, and T5 = CVVHF off for over 48 hours. The mean (SD) PFHb levels were 19.6 (10.9) at T1, 31.7 (0.6) at T2, 93.7 (16.4) at T3 (p < 0.05), 32.5 (20.9) at T4, and 14.2 (3.8) at T5 (p < 0.05). These changes were paralleled by the mean (SD) HBD levels: T1 = 1,337 (616), T2 = 2,025 (509), T3 = 2,676 (1,170) (p < 0.05), T4 1,780 (618), and T5 = 1,310 (436). CONCLUSIONS: Thoratec VAD was associated with a mild degree of hemolysis. This was worsened by concomitant use of CVVHF. The effect was accentuated if the same CVVHF circuit was used for over 48 hours but was reversible within 24 hours of stopping the hemofilter.

Adult↗
PubMed2002

Maxillonasal dysplasia (Binder syndrome): a lateral cephalometric assessment.

Binder syndrome or maxillonasal dysplasia was first described by Binder in 1962, and is a disorder characterised by nasomaxillary hypoplasia. The records of 33 patients who had been diagnosed clinically with Binder syndrome at the Royal Children's Hospital of Melbourne were examined. Of these 33 patients, 14 were selected because they met the incusion criteria: that they had not had prior surgical and/or orthodontic treatment, and that high-quality lateral cephalometric radiographs were available. The craniofacial morphology of these patients was determined on lateral cephalometric radiographs and compared with published age- and sex-matched norms. In agreement with published studies, the anteroposterior lengths of the anterior cranial base and maxilla were reduced, and the majority of patients had a Class III skeletal relationship. Although the lower incisors tended to be prominent, both overjet and overbite 'ell within the ranges for the normal population. Despite the fact that the orthodontic and surgical treatment for patients with Binder syndrome is normally carried out within specialised units, clinicians should be aware of the variety of ways in which this condition may present.

Adolescent↗
PubMed2002

Lower incisor changes on basal bone and in relation to the lower face: combined growth and treatment effects in the late mixed-dentition.

This study was designed to determine and compare the ranges of combined growth and late mixed-dentition treatment changes in the positions of the lower incisors, either on basal bone or in relation to the APog line. While there was considerable individual variation, movements of the lower incisors in relation to APog were found to be related more to changes in the angulation of the APog line itself, than to the movements of the incisors on the basal bone. In individual cases in which considerable forward movement had occurred at pogonion and in which deep anterior overbites had been reduced, it was often found that the lower incisors had moved forward considerably in relation to the APog line without necessarily having moved forward at all on the underlying basal bone. It was concluded therefore that, in such cases, lower incisor movements on basal bone may actually occur in the opposite direction to those in relation to the APog line because of the complex interaction of changes occurring in the vertical and horizontal positions of both point A and pogonion. In these cases, it seems possible for the lower dentoalveolus to be passively carried forward with growth of the underlying basal bone, once any deep overbite has been reduced.

Analysis of Variance↗