<PAGE>   1
                                                                   EXHIBIT 10.35




                                 PROMISSORY NOTE
                                 BY AND BETWEEN
                               CHARLES A. LAVERTY
                                       AND
                             UROHEALTH SYSTEMS, INC.


Principal Amount:  $1,500,000                              DATED:  APRIL 2, 1997

        FOR VALUE RECEIVED, Charles A. Laverty ("MAKER"), does hereby promise to
pay to UROHEALTH Systems, Inc. ("HOLDER"), in lawful money of the United States
and in immediately available funds, the principal amount of one million five
hundred thousand dollars ($1,500,000), with interest compounding annually
thereon. Interest shall accrue at a per annum rate equal to six and two
one-hundredths percent (6.02%).

        The balance of the principal amount of the Note outstanding and all
accrued and unpaid interest thereof shall be due and payable in full upon the
earlier of (a) November 25, 1999 or (b) within thirty (30) days of the
termination for any reason of that certain Employment Agreement by and between
Maker and Holder in effect as of the date hereof. Maker agrees to apply any
future bonuses awarded Maker by the Compensation Committee of the Board of
Directors of Holder to the repayment of the principal amount of this Note.

        Payment shall be delivered to Holder at the address as set forth below,
or at such other address as designated by Holder.

               The following shall constitute an Event of Default:

   (i)   A default in payment by Maker to Holder of any payment due hereunder,
         when due and payable which continues for five (5) days after any such
         payment is due; or

   (ii)  Maker shall be adjudicated a bankrupt, or a decree or order approving
         as properly filed a petition or answer asking reorganization of Maker
         under the federal bankruptcy laws, as now or hereafter amended, or
         under the laws of any state, shall be entered, and any such decree,
         judgment, or order shall not have been vacated, stayed, or set aside
         within ninety (90) days from the date of its entry or granting; or

   (iii) Maker shall file, or admit the jurisdiction of the court and the
         material allegations contained in, any petition in bankruptcy or any
         petition pursuant to, or purporting to be pursuant to, any current or
         future acts of Congress on the subject of bankruptcies or any
         amendments to such acts, or Maker shall institute any proceedings, or
         Maker shall give its consent to the institution of any proceedings,
<PAGE>   2
         for any relief of Maker under any bankruptcy or insolvency laws, or any
         laws relating to the relief of debtors, readjustment of indebtedness,
         reorganizations, arrangements, compositions, or extensions; or

   (iv)  Maker shall make any assignment for the benefit of creditors or shall
         apply for a consent to the appointment of a receiver for Maker or any
         of the property of Maker; or

   (v)   A decree or order appointing a receiver of the property of Maker shall
         be made and the decree or order has not been vacated, stayed, or set
         aside within ninety (90) days from the date of its entry or granting.

        Upon the occurrence of an Event of Default, the entire outstanding
principal balance together with accrued interest hereunder shall, at the option
of Holder, become immediately due and payable and Holder shall thereupon have
all rights and remedies provided hereunder, in any other agreement between Maker
and Holder, or otherwise available at law or in equity.

        Maker waives presentment, demand for payment, notice of dishonor, and
all other notices or demands in connection with the delivery, acceptance,
performance, or default of this Note.

        Nothing herein contained, nor any transaction related hereto, shall be
construed or so operate as to require Maker, or any other person liable for
repayment of same, to pay interest at a greater rate than is now lawful in such
case to contract for, or to make any payment, or to do any act contract to law.
Should any interest or other charges paid by Maker, or parties liable for the
payment of this Note, result in the computation or earning of interest in excess
of the maximum rate of interest which is legally permitted under the laws of the
applicable jurisdiction, then any and all excess shall be and the same is hereby
waived by the Holder, and any and all such excess shall be automatically
credited against and in reduction of the balance due under this indebtedness,
and the portion of said excess which exceeds the balance due under this
indebtedness shall be paid by the Holder here for the Maker and parties liable
for the payment of this Note.

        All notices, requests, demands, and other communications provided for
hereunder shall be in writing and shall be deemed to have been duly given if (i)
delivered in person; (ii) given by prepaid telex or telegram, or by facsimile or
other instantaneous electronic transmission device; (iii) sent by Federal
Express or other nationally recognized overnight delivery service, charges paid
by the sender, or (iv) deposited in the United States mail, first class,
registered or certified, return receipt requested, with proper postage prepaid,
as follows:




<PAGE>   3
                       If to Maker:

                       2230 North Euclid Avenue
                       Upland, CA  91784

                       If to Holder:

                       Suite 100
                       5 Civic Plaza
                       Newport Beach, CA  92660
                       Attn:  General Counsel

        Notices given pursuant to (I), (II), and (III) above shall be deemed
received and effective upon receipt by the addressee thereof. Notices given
pursuant to Section (iv) above shall be deemed received and effective three (3)
days after the date deposited in the mail.

        In the event of a dispute between the parties arising from this Note,
the prevailing party shall be entitled to recover reasonable attorney's fees and
cost of the suit.

        This note shall be governed by the laws of the State of California.


                                             CHARLES A. LAVERTY


                                               /s/ CHARLES A. LAVERTY
                                             -------------------------------
                                             Signature