Herbert Cares, M.D.

Scientific Article

[This is the first series in the world literature of ruptured lumbar disc surgery performed on an outpatient basis.]

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Copyright © 1988 by the Congress of Neurological Surgeons
Vol, 22, No. 3, 1988
Printed in U.S.A.

Ambulatory Microsurgery for Ruptured Lumbar Discs: Report of Ten Cases

Herbert L. Cares, M.D., Robert S. Steinberg, M.D.,
Edgar T. Robertson, M.D., and Paolo Caldini, M.D.

Departments of Neurosurgery, Orthopedics, Neurology, and Anesthesiology, Newton- Wellesley Hospital, Newton, Massachusetts

Advances in microsurgical techniques combined with a widening interest in same-day surgery led us to investigate ambulatory lumbar discectomy. We could find no precedent in the literature. Ten patients with classic ruptured lumbar discs confirmed by computed tomography chose to participate. They were aged 31 to 5 1, seven men and three women, in excellent general health. A microsurgical approach through a 25-mm skin incision was performed. The technique emphasized removal of sufficient medial facet to allow excision of the disc with minimal or no root retraction. Once awake in the recovery room, patients were transferred to a separate ambulatory step-down unit. They were discharged only after they had voided, ambulated, taken oral nourishment, and been examined by the surgeon. A visiting nurse checked the patient at home the evening of operation and the next day. All returned to their usual occupation between 3 and 14 days postoperatively. All were satisfied and would choose the outpatient program again. Our experience indicates that ambulatory lumbar microdiscectomy can be a safe, effective option for selected patients. (Neurosurgery 22:523-526, 1988)

Keywords: Ambulatory surgery, Intervertebral disc surgery, Lumbar vertebra, Microsurgery

Early postoperative mobilization (12), improved microsurgical technique (3), and widening interest in same-day surgery led us to investigate ambulatory lumbar discectomy. We report our initial experience with 10 patients. We could find no previous reports in the literature.


Patient selection

All patients had leg pain refractory to routine conservative measures, focal signs of nerve root compression, and a unilateral ruptured lumbar disc demonstrated by computed tomographic (CT) scan. These features are documented in Table I and illustrated in Figure 1. The first patient had a myelogram on a previous admission; the remainder had CT scans alone. All were under 55 years of age, were in general good health, and were American Society of Anesthesiology Class I (11). Patients whose disease followed an industrial or motor vehicle accident were excluded. Each patient chose the outpatient surgery program voluntarily. Demographic details of the patient population are shown in Table 2.

Preoperative preparation

Patients were informed about the expected benefits and risks of operation and about the usual course in the recovery room, in the day surgery unit, and at home. They were told that they would have incisional pain and might have paresthesias in the distribution of their preoperative radicular pain. At least two patients discussed the experience with alumni of the program.

Frequent walking was encouraged for a week preoperatively to avoid potential thromboembolicc disease. Within 3 days before operation, patients underwent complete blood count, urinalysis, electrocardiogram, chest roentgenogram, and coagulation profile (prothrombin time, partial thromboplastin time, bleeding time, and platelet count). Patients came to the hospital on the morning of operation having taken nothing by mouth after midnight. No preoperative medication was given.


General endotracheal anesthesia was used, in accordance with established standards for ambulatory anesthesia (5). No preanesthetic medications were given. In all patients, general anesthesia was induced with thiopental, 6 mg/kg, followed by succinylcholine to facilitate tracheal intubation. Anesthesia was maintained with 60% nitrous oxide and I to 2%, isoflurane. Incremental doses of fentanyl and nondepolarizing muscle relaxants were used to maintain stable, balanced anesthesia. An effort was made to minimize the amount of narcotic used intraoperatively; the doses given are shown in Table 3.

Surgical technique

Patients were positioned prone on laminectomy rolls. Loupes were used, and a 25-mm incision was made in the midline over the spinous processes of the involved interspace, which was located by palpation. The aponeurosis of the lumbodorsal fascia was divided 5 mm from the midline, and the paraspinal muscles were retracted laterally with a specially modified Taylor retractor. An operating microscope was used for the remainder of the procedure. Although the technique was similar to those previously reported (3, 6), emphasis was placed on removal of the medial portion of the facets with a high speed diamond-burred air drill and microrongeurs. This allowed exposure of the disc and adjacent anatomy, including the second, higher root, with minimal or no root retraction. Free disc fragments, if present, were removed, the annulus was opened sharply, and the interspace was cleared of loose disc. At the end of the dissection, the operative team could see into the interspace with no retraction of the dura mater or root, which was slack and pulsatile. The wound was closed in layers with a subcutaneous inverted interrupted skin closure, and a vapor-permeable dressing was applied.

Postanesthesia care

Recovery room care was the same as for other outpatients having general anesthesia (14). Intravenous fluids were discontinued, and a heparin lock was placed before discharge from the recovery room to an ambulatory step-down unit. The importance of the segregation of outpatient from inpatient has been emphasized (14). Once in the step-down unit, patients received only oral analgesics. They were discharged when they met generally accepted discharge criteria (14), in particular after they had voided, walked, retained food, and been examined by the surgeon. Patients were taken home by family members between 3 and 6 p.m. Details of the postanesthetic experience are in Table 3.


Clinical Characteristics of Patient Population

Case Duration of Symptoms Focal Deficitsa Level of CT Abnormality Findings at Operation
1 9 wk Flaccid EHL L4-L5, R Free fragment
2 8 wk Trace AJ L5-Sl, L Ruptured disc
3 1 yr Diminished AJ, gastrocnemius 4/5 L5-Sl, L Ruptured disc
4 3 wk Diminished AJ, EHL 4/5 L5-SL L Free fragment with superior migration
5 2 mo Diminished AJ, gastrocnemius 4/5 L5-Sl, R Large free fragment
6 8 mo Absent AJ, gastrocnemius 4/5 L5-S1, L Ruptured disc
7 5 mo Gastrocnemius 4/5 with fasciculations L5-SI, L Small ruptured disc shallow lateral recess
8 3 mo EHL 3/5, positive Trendelenburg sign L4-L5, L Ruptured disc with inferior migration
9 5 wk Diminished AJ, gastrocnemius 4/5 L5-S1, L Ruptured disc
10 6 mo Absent AJ, gastrocnemius 4/5 L5-S1, R Free fragment impacted under S1 foot

Abbreviations: AJ, ankle jerk; EHL, extensor hallucis longus.

A B  
Disc photo Disc photo  
C D  
Disc photo Disc photo  

















FIG. 1. A: CT scan of Patient I through the L4-L5 interspace after water-soluble contrast myelography. Note the ruptured disc fragment (arrow), extending inferiorly over the body of L5.
B: CT scan of Patient 2 through L5-S1. Note the typical unilateral disc herniation on the left (arrow).
C: CT scan of Patient 4 through L5-S1, showing herniated disc (arrow). A free fragment was found at operation.
D: CT scan of Patient 9, showing substantial unilateral lumbosacral disc herniation (arrow).


Demographic Characteristics of Patient Population

Case Hospital Sex Age Occupation
1 MWRH Male 41 Auto Body Repair
2 NWH Female 37 Housewife
3 NWH Male 32 Engineer
4 NWH Male 33 Epidemiologist
5 WWH Male 32 Factory worker
6 NWH Female 39 Housewife
7 NWH Female 31 Nurse
8 NWH Male 43 Accountant
9 WWH Male 51 Factory foreman
10 NWH Male 32 Construction foreman

Abbreviations: MRWH = Milford-Whitinsville Regional Hospital; NWH = Newton-Wellesley Hospital; WWH = Waltham-Weston Hospital.

Care after discharge

A visiting nurse saw the patient at home and either the patient or the visiting nurse telephoned the surgeon during the evening of operation and on the next day. Further telephone contact with the surgeon was encouraged. Patients returned to the surgeon's office within a week for removal of the vapor-permeable dressing and postoperative evaluation.


Five patients had free fragments at operation. All patients were relieved of leg pain, all were satisfied, and all were back at their usual occupations in 3 to 14 days (Table 2). No patient had wound hematoma or infection, urinary retention, or thromboembolic disease. One patient had a fever of 101 *F on the night of operation; it resolved by the next morning. No patient required hospitalization on the day of operation or later. Patient compliance approached 100%. Each patient, when asked, stated that he or she would choose the outpatient mode again.


Intraoperative and Postoperative Narcotics and Analgesics

Case Narcotics Intraoperative Time in Recovery Room (min) Pain/Nausea Medication
in Recovery Room
Time in Stepdown
Unit (min)
Pain/Nausea Medication
in Stepdown
1 Morphine, 5 mg None 75 None 130 Acetominophen
2 None 100 Propoxyphene 65 170 None
3 Fentanyl, 0.05 mg 60 None 300 Acetominophen
4 None 120 None 215 Acetominophen

Fentanyl, 0.2 mg

80 Oxycodone 180 Oxycodone
6 Fentanyl, 0.05 mg 120 Inapsine 190 None
7 Fentanyl, 0.05 mg 110 None 115 Acetominophen
8 Fentanyl, 0.05 mg 120 None 175 None
9 Fentanyl, 0.05 mg 120 None 130 Acetominophen
10 Fentanyl, 0.2 mg 90 Oxycodone 150 None


Patient safety was a paramount concern. Four safeguards were incorporated in the program's design. Patients were carefully screened, and those with the slightest potential medical problem were excluded. For example, one candidate only 33 years old and in excellent general health was excluded because he had a brother who had died at 31 of a myocardial infarction. The surgical team was sufficiently experienced so as to discern the slightest deviation from an optimal intraoperative or postoperative course. Our own and published experience suggests that serious complications are likely either to be manifest in the recovery room (such as great vessel injury) or to remain obscure for several days (such as wound infection) (2). Thromboembolic disease is reported rarely (less than 1% (12)), if at all (3), and we hope that it was minimized by the outpatient format. Had the slightest concern on the part of the patient, physician, or visiting nurse arisen as to added risk at any stage, the patient would have been hospitalized. With these safeguards, the outpatient format did not expose patients to additional risk. Incidentally, we did not provide for physician house calls in our protocol because this would be a distortion of the outpatient format.

Patient comfort was also a concern. Few patients needed parenteral medication after leaving the recovery room after unilateral lumbar disc operation. Less sedated patients feel more in control and are less likely to ask for pain medication (10). Outpatients in this study had the same analgesics as our inpatients. At first, we infiltrated the wound with bupivacaine before closing (8), but we did not use it as a rule and found no difference when this step was omitted.

Some patients find confinement in the hospital, with enforced isolation from family and friends and the imposition of an alien routine, more frightening and stressful than being home in a familiar, private environment. This seemed to play a role in the motivation of the patients in this study. Each patient's choice of the outpatient program was voluntary from the outset and remained so; at any time, a patient was free to change his or her mind about going home.

The relative merits of microsurgery vs. a more traditional approach have been discussed elsewhere (15). We think that microsurgery allows a safer operation and, with a smaller incision, there seems to be less of a perceived sense of bodily violation.

The patients in this study came from three Massachusetts counties, underwent operation at three different hospitals, and were served by a variety of visiting nurse associations. This approach is well within the capabilities of existing facilities.

The performance of lumbar disc operation on ambulatory patients is a logical projection of current trends (4, 13). According to the Commission on Professional and Hospital Activities (1), the mean length of stay for simple lumbar disc excision in patients between 20 and 55 years of age decreased from 9.0 days in 1981 to 7.9 days in 1985, the most recent year of available data. No national figures are available specifically for postoperative length of stay but, in our Health Service Area (greater Boston), the average postoperative length of stay for patients undergoing unilateral lumbar disc excision in acute care, nonfederal hospitals in 1984 was 5.6 days (7).

Not every patient is a suitable candidate for outpatient discectomy, and not every medically suitable patient will choose it. The existence of an outpatient option, however, should influence the perspective of patients requiring lumbar disc surgery. Consumer demand for what appears as a less invasive alternative was demonstrated in the enthusiasm for chemonucleolysis (9) and should not be underestimated. Preliminary experience indicates that ambulatory lumbar microdiscectomy is a safe, effective option for selected patients.


The authors thank Howard Richter, M.D., and Claudette Healey, C.R.N.A., for assistance in preparation of the manuscript. The authors also thank Nicholas Zervas, M.D., for reviewing the manuscript.

Received for publication, June 27, 1987; accepted, September 16, 1987.

Reprint requests: Herbert L. Cares, M.D., 2000 Washington Street, Suite 220, Newton, MA 02162.


1. Commission on Professional and Hospital Activities: Length of Stay by Operation, United States, Northeastern Region, 1984. CPHA, 1985.

2. Horwitz NH, Rizzoli, HV: Postoperative Complications in Neurosurgical Practice. Baltimore, Williams and Wilkins, 1967, pp 237-257.

3. Hudgins RW: The role of microdiscectomy. Orthop Clin North

Am 14:589-603, 1983.

4. Hudgins RW: Comment. Neurosurgery 16:147, 1985.

5. Lichtiger M, Wetchler BV, Philip BK: The adult and geriatric patient, in Wetchler BV (ed): Anesthesia for Ambulatory Surgery. Philadelphia, JB Lippincott, 1985, pp 175-224.

6. Maroon JC, Abla A: Microdiscectomy versus chemonucleolysis.

Neurosurgery 16:644-649, 1985.

7. Massachusetts Health Data Consortium, Inc: Post-Operative Stay, Patients Ages 20-55, Excision of Intervertebral Disc 1984. Report, Oct 15, 1986.

8. Mullen JB, Cook WA: Reduction of postoperative lumbar hemilaminectomy pain with Marcaine. J Neurosurg 51:126-127, 1979.

9. Nordby EJ: A comparison of discectomy and chemonucleolysis.

Clin Orthop Res 279-283, 1985.

10. O'Donovan TR, O'Donovan PG: The future is now, in Wetchler BV (ed): Anesthesia for Ambulatory Surgery. Philadelphia, JB Lippincott, 1985, pp 1-32.

11. Orkin FK: Selection, in Wetchler BV (ed): Anesthesia for Ambulatory Surgery. Philadelphia, JB Lippincott, 1985, ch 3, pp 77123.

12. Sachdev VP: Microsurgical lumbar discectomy: A personal series of 300 with at least I year of follow-up. Microsurgery 7:55-62, 1986.

13. Scoville WB, Corkill G: Lumbar disc surgery: Technique of radical removal and early mobilization. J Neurosurg 39:265-269, 1973.

14. Wetchler BV: Problem solving in the postanesthesia care unit, in Wetchler BV (ed): Anesthesia for Ambulatory Surgery. Philadelphia, JB Lippincott, 1985, ch 7, pp 275-320.

15. Wilson DH, Harbaugh R: Microsurgical and standard removal of the protruded lumbar disc: A comparative study. Neurosurgery 8:422-427, 1981.


The authors have demonstrated what many experienced spine surgeons have recognized as possible, but had no incentive to do. They have performed outpatient microdiscectomies in highly selected, healthy, young adults with no other medical problems and classical clinical and radiographic findings. They also were highly motivated patients who were not on compensation.

On several occasions, we have discharged patients within 24 hours of microdiscectomy with similar good results. As we reported, the average postoperative stay for our patients is 3 days, but in retrospect we estimate that 10 to 20% of our patients could be safely discharged on the same evening or the next day if there was follow-up care by a visiting nurse and, psychologically, the patients were well prepared and informed of all aspects of their treatment and care.

With the refinement in surgical technique and the elimination in many cases of invasive diagnostic procedures, outpatient microdiscectomy seems to be a reasonable option in the highly selected and informed patient. As the authors state, however, every patient is not a suitable candidate for outpatient discectomy. Although insurance carriers undoubtedly

Neurosurgery, Vol. 22, No. 3

would be delighted to see this done routinely, physicians must constantly bear in mind that many patients consider any invasive procedure and, in particular, "back surgery" a serious undertaking. Many patients require the psychological and medical support available in a hospital.

Joseph C. Maroon
Pittsburgh, Pennsylvania

The authors have satisfactorily demonstrated in this small group of selected patients that surgery for ruptured disc can be accomplished in an ambulatory setting. This is not only commendable, but also proves once again that open operation is less traumatic and allows a better recovery than intradiscal therapy.

In my opinion, however, the reason for their success, is not microdiscectomy but rather the selection of appropriate patients. My personal opposition to the operation known as lumbar microdiscectomy stems from the fact that there is inadequate exposure and unsatisfactory decompression for the massive ruptured disc. In a number of cases where further bone removal would be advantageous, there is a high rate of complications, especially dural tears, in the large series reported. Furthermore, I have reoperated on some patients who have had this procedure to remove retained, undetected fragments of extruded disc (1).

The majority of patients who undergo operation for ruptured disc at our institution are hospitalized for I night, many of these because they must travel significant distances to their homes. They are, of course, ambulatory on the afternoon of operation and require only oral analgesics, although their skin incisions are more likely to approximate 250 mm than 25 mm.

Charles A. Fager
Burlington, Massachusetts

1. Fager CA: Lumbar microdiscectomy: A contrary opinion. Clin Neurosurg 33: 1986.